Energy from human activity - Page 1
Forum section: electronics / general

author: DenCraw
author_rank: Contributor
timestamp: September 23, 2019, 03:15:14 pm
content: Hi.I am Dennis, I live in Spain.I wonder how much power could be "sucked" from a gym.I don't know how many watts the human body produces while training, as well, I don't know what is the expected efficiency from a well designed gym machinery.(dynamo)How much is lost in heat, and mechanical transmission etc.best regards.Dennis(No. I am not planning to do a Matrix)

author: tom66
author_rank: Super Contributor
timestamp: September 23, 2019, 03:23:28 pm
content: Average dissipation of an idle human is around 150 watts.An average healthy male can output around 250 watts.A professional athletic cyclist can output around 800 watts ~ 1000 watts in short bursts.But the metabolic efficiency of a human is barely 20%. If you feed the human from beef burgers, then it is probably much worse than powering things from a diesel generator. From plants it is probably a little better.Quick calculation. A cyclist burns about 50 kcal per mile. A quarter pounder beef burger is 225 kcal so one burger = 4.5 miles or 7.2 km of cycling. Roughly 36 kg of CO2e is produced or negatively offset, in the production of 1 kg of beef, so our burger costs us about 3.6 kg of CO2e. 7.2 km on 3.6 kg of CO2e is about 500gkm/CO2e.The best petrol cars are around 1/4 of that and electric cars even better, so cycling (powered by beef burgers) is worse for the environment than driving a petrol car. Of course, vegans have moral superiority here.

author: FreddieChopin
author_rank: Regular Contributor
timestamp: September 23, 2019, 04:48:54 pm
content: Quote from: tom66 on September 23, 2019, 03:23:28 pmWhat about oil changes, timing belts, tyres, acid in batteries? I had my MTB for 12 years already and the only thing im changing is brakes and chain every 3 years. Everything else either broke years ago or doesnt need replacing.

author: SiliconWizard
author_rank: Super Contributor
timestamp: September 23, 2019, 04:58:32 pm
content: I remember we already talked about that on a topic about a startup? willing to do this kind ot thing to recharge batteries while people would be pedalling on bicycles.So are we going to repeat indefinitely that energy doesn't come from nowhere?If you're going to "suck" energy from any human activity, said humans will just have to produce more energy for the given task than if you didn't suck any. That's pretty simple.Whether some people are OK with that - ask them. Sure, at least you're targetting gym settings, so yeah, machines have to resist human force anyway and that's wasted energy. You could replace that with something that actually uses the energy for something. That still doesn't mean everyone would be OK with it. Why so? Unless they get something back from that, many if not most people will prefer wasting their own energy rather than give it away for free to someone else, especially if this is for profit!tom66 gave some figures (that IIRC seem to be in the right ballpark) that could give you an idea of what you could technically expect. And that's not very interesting, not even from an environment POV actually!

author: Bud
author_rank: Super Contributor
timestamp: September 23, 2019, 05:08:49 pm
content: If people are smart enough to care about their health and go to gym, they would not eat burgers.

author: FreddieChopin
author_rank: Regular Contributor
timestamp: September 23, 2019, 05:14:04 pm
content: Quote from: SiliconWizard on September 23, 2019, 04:58:32 pmHonestly I also don't understand what's the point of wasting energy on a gym machine. If you drive a bike then at least you get to see countryside, maybe you'll find something cool (once after a rain I spotted 2 7.92x57 Mauser shells from 1938, fired from MG42 - so the place has history). Gym would be fun if it ended in strength exercise like that

author: SiliconWizard
author_rank: Super Contributor
timestamp: September 23, 2019, 06:38:01 pm
content: Quote from: FreddieChopin on September 23, 2019, 05:14:04 pmWell, that's a fair point. You of course know the answer. It's all related to the way most of us live - in a very sedentary manner. Many in cities in which what you describe is unfortunately not much of an option, or could even be unsafe. So people just exercise on machines instead, just to stay healthy. Well, in an attempt no to become too unhealthy anyway...

author: tom66
author_rank: Super Contributor
timestamp: September 23, 2019, 09:05:07 pm
content: Quote from: FreddieChopin on September 23, 2019, 04:48:54 pmI don't mean to deride cyclists - by all means please do cycle.Just an interesting energy comparison - powering a 1.5-tonne petrol car is more efficient than a 150kg-human+bike, despite the car weighing 10x as much, if the cyclist eats a primarily meat-based diet. Maintenance is obviously excluded, annual oil changes and services probably do contribute some more emissions.Vegans and vegetarians will do much better than meat eaters in terms of carbon emissions - it is just physics. Since if you eat a beef burger or beef products to cycle, there are three conversions: sunlight to grow crops, those crops fed to a cow, and that cow fed to a human then cycling under stress. So it is understandable that it is very lossy.If you eat the crops directly (e.g. plant based diet) then cycling is probably better than a petrol car but an electric car is probably still better. A cyclist eating just chicken is probably about the same as a petrol car, as chicken is much more efficient than beef.This website says vegan burgers produce 10% of the emissions of regular beef burgers. (https://www.plantbasednews.org/lifestyle/vegan-beyond-burger-more-sustainable-beef) That puts the veggie burger cyclist at about half the emissions per km of that of the petrol car, but still about twice as much an electric car per km on UK electricity.Probably the best option here is an e-bike or e-scooter; little human energy input but also much less electrical energy required to power it. But then you don't get fit!

author: Seekonk
author_rank: Super Contributor
timestamp: September 23, 2019, 09:08:01 pm
content: Most people at a gym can't do 50W.

author: Mr. Scram
author_rank: Super Contributor
timestamp: September 23, 2019, 09:43:55 pm
content: Who eats a primarily meat based diet? Even the meat centric US doesn't seem to manage that. Of course just proteins and fats won't properly sustain a human. You need carbohydrates to burn and those tend to come from plants. Note that this is mainstream medical and dietary knowledge. If you make different choices or have different beliefs that's for another thread

author: Mr. Scram
author_rank: Super Contributor
timestamp: September 23, 2019, 09:46:24 pm
content: Quote from: tom66 on September 23, 2019, 09:05:07 pmWhere's your calculation? The few sources I find seem to conclude that the impact of cycling is about a tenth of driving a car per distance. Some diets can indeed be worse than others but you obviously also tend to drive further than cycle.https://ecf.com/files/wp-content/uploads/ECF_BROCHURE_EN_planche.pdf

author: DenCraw
author_rank: Contributor
timestamp: September 24, 2019, 07:08:11 am
content: "Vegans and vegetarians will do much better than meat eaters in terms of carbon emissions"Quote from: tom66 on Yesterday at 09:05:07 pmWell that is a strange statement.I am in a Healty Keto diet since April and besides went down to 73Kg from 87, from my previous believes on carb diet, my blood constants, liver levels, kidneys, are perfect as 20 years ago!.The amount of intake calories are compose of 70% FAT, 20% Protein and 10%Carbs. I do OMAD, one meal a day, doing exercise and as a bonus, i produce less CO2 than the vegans.The navy seal are adopting this diet.But the point is, given that the people, here in Spain, are going massively to the gym, I thought that it is worth to recover that energy for doing something useful.

author: tom66
author_rank: Super Contributor
timestamp: September 24, 2019, 07:11:06 am
content: Quote from: Mr. Scram on September 23, 2019, 09:46:24 pmAs above in post #1 though I did assume the cyclist only ate beef, which as Scram mentioned is unusual, although I do know some people whose diet is probably 80% meat (in calorific value).1kg beef produces 36kg CO2 - sourcehttps://www.theguardian.com/environment/2007/jul/19/climatechange.climatechangeA quarter pounder burger weighs 113g (duh), effectively produces 4.06kg CO2e and has a calorific value of ~225kcalhttps://www.myfitnesspal.com/food/calories/112885313So 1kcal = 18g CO2. 50kcal per mile for an average cyclist, 1 mile = 904g CO2 = ~560gCO2/kmQuoteI would be interested to see what the figures look like for a more typical diet, as I really only did this as a thought experiment on how inefficient humans are at extracting energy from their food, especially if we eat an animal that has also had to do that conversion into muscle mass.(I am a meat eater, for what it is worth, though I have reduced my diet to consist mostly of chicken with beef only once a fortnight.)

author: martin1454
author_rank: Regular Contributor
timestamp: September 24, 2019, 07:14:02 am
content: When I use the crosstrainer or bike in the gym, im around 200W for 30min, so around 100Wh - If everybody did that, it would make a bit of power but nothing significant

author: Zero999
author_rank: Super Contributor
timestamp: September 24, 2019, 09:18:00 am
content: Quote from: DenCraw on September 24, 2019, 07:08:11 amI've done a similar diet before. It worked in the short term, but not for long. Five months is nothing. See what happens to your body after five years of that diet.Yes it's true that sort of diet is bad for the environment. It takes much more energy and CO2emissions to grow plants, feed them to animals and eat the animals, rather than to just eat the plants in the first place. The only time it makes sense to eat animals, is in places, with lots of natural, non-nutritious vegetation (mountains, grasslands, tundra) and aren't suitable for agriculture, but it's not possible to sustain a large population density of humans. Even in those instances, it's often better to import food or use technology such as greenhouses or irrigation to grow crops, than eat meat.I used to be overweight and slimmed down without changing my diet, which wasn't the problem in the first place. I just exercise lots and get the extra calories from plant based carbohydrates. I'm not vegetarian. I do eat meat, but it's not where I get my extra calories from, when I exercise.Quote from: tom66 on September 23, 2019, 09:05:07 pmHow many people weigh 150kg? That's well over double my bodyweight and is very fat, even in the US!I believe when people increase their activity levels, they get most of their extra calories from carbohydrates, rather than meat. I find when I'm really active, I tend to get cravings for bread, sugar, cake etc. not steak, fish, chicken etc. If someone starts cycling to work, rather than driving, I doubt they'll eat that much more meat, but more carbohydrates.QuoteAnd vegan burgers are probably an inefficient source of food, compared to basic carbohydrates such as potatoes, sugarbeat, wheat, oats etc.QuoteYou're better growing a lot of your own food, which will also keep you fit!EDIT:How about all the pollution and emissions in making the battery, which is also difficult and currently not economical to recycle?

author: tszaboo
author_rank: Super Contributor
timestamp: September 24, 2019, 10:09:38 am
content: The thing is, you can modify a cycle in a gym to generate electricity. Just put a generator on it, and thats it. And it will be a huge waste of energy and resources, and never will be worthwhile.Let's say you put a generator on a bike. And people use it 8 hours a day when the gym is open, and half the time it is used.That 250W from the second post is not average output, it is peak output. I went on ECG where I had to do biking, at 250W-350W I was almost passing out after a while (which was the point of the test). On average you will get something like a 100W. That is 146KWh per year, if the gym is open every day.One solar panel would generate you 200-300KWh per year.

author: Mr. Scram
author_rank: Super Contributor
timestamp: September 24, 2019, 11:11:28 am
content: Regardless of the CO2situation having people cycle more will inevitably lead to more carbon emissions. When people are healthier they live longer and need more care towards the end of their lives. The most environmental friendly human is dead. Leading a sedentary lifestyle is likely the best thing you can do for the environment.

author: Gyro
author_rank: Super Contributor
timestamp: September 24, 2019, 11:44:35 am
content: Quote from: NANDBlog on September 24, 2019, 10:09:38 amOur new LG washing machine, purchased last week has an energy consumption rating of A+++ minus 30% (we really need to update that rating system!). The actual consumption figure is 132kWh/year, based on the 220 wash standard.With regular strenuous visits to the gym, you would be able to wash your gym clothes, towels etc. (and those of a few other members) for free!

author: tszaboo
author_rank: Super Contributor
timestamp: September 24, 2019, 11:51:16 am
content: Quote from: Gyro on September 24, 2019, 11:44:35 amOr go to the well regularly and wash your clothes there.

author: Zero999
author_rank: Super Contributor
timestamp: September 24, 2019, 12:56:39 pm
content: Quote from: Mr. Scram on September 24, 2019, 11:11:28 amIt depends on how much care they need and for how long. Someone with type 2 diabetes might need a lot of care from a relatively early age, compared to someone who's more fit and healthy and dies a few years later, but very quickly. Exercise is said to help avoid health problems such as dementia, which are very costly to treat. It's an interesting thought though.

author: metrologist
author_rank: Super Contributor
timestamp: September 24, 2019, 01:35:24 pm
content: Quote from: tom66 on September 23, 2019, 03:23:28 pmWhat is a gkm?

author: martin1454
author_rank: Regular Contributor
timestamp: September 24, 2019, 01:43:08 pm
content: Quote from: metrologist on September 24, 2019, 01:35:24 pmGram per KilometerG/Km

author: amspire
author_rank: Super Contributor
timestamp: September 24, 2019, 03:20:58 pm
content: Quote from: tom66 on September 23, 2019, 03:23:28 pmThe problems I have with vegans is that their moral superiority tends to be based on appalling science. There is actually very little good science supporting vegan diets - the scientific support for low carb/keto diets is far more robust at this stage. I have actually looked at the studies that some of the most prominent vegans are saying justifies their diet, and the studies they highlight to me as an engineer are very problematic studies. If anyone actually knows of any solid scientific research papers supporting the vegan diets over low carb diets, please let me know. I would love to see them.The Standard American (Australian) diet is not supported by science at all. Since this fad diet has been foisted on the world in the 1980's, there has been a very dramatic worsening of health to the point it is now a major crisis. Healthcare will not be affordable in 10 years. In the case of the Australian diet, it is reviewed once in 10 years, and the last review (2013) was done by one person (a contractor) who studied about 12 topics in total. The budget for this 10 year review was something like 1/2 a million dollars. Prior to 2013, there had been 3 major metastudies that reviewed all the evidence on saturated fat and these studies clearly stated the result was that there is just no evidence anywhere of any health problem with saturated fat. In the Australian 2013 dietary guidelines, they actually said in the appendix that they deliberately did not look at any evidence on saturated fat as it wasn't going to change their minds. That is not evidence based science.The argument that vegan diets are better for the planet are also very weak.Pasture animals can be 100% energy neutral, fields do not have to be fertilised or plowed which preserves the pasture. Cows do not naturally eat diets of corn and other grains - it makes them diabetic. It makes the meat a health problem for humans - just as with eggs from grain fed chickens and meat from grain fed pigs. Basically, we need to move away from industrialised animal agriculture and go back to a more local sustainable agriculture. This would be totally feasible in places like Australia. Harder in the US and Northern Europe. You would have to use stored hay in winter rather then grain.Low carb and keto diets are not high protein diets - the percentage of protein is no more then more then most standard diets, and typically people on low carb and keto diets eat about 500 to 1000 kcals less then they did on the standard diets - they feel full and do not want to eat as much as they used to. On the keto diet, it is very easy to eat only one meal a day, or to not eat for 3 days if you are not hungry. On a keto diet, when you do not eat, you often have more physical energy if your body has a good store of fat. I started bike riding last year at the age of 62 and I never get hungry or tired after a 50km ride - about the longest rides I am doing at the moment.As an engineer looking at the biggest current killer - heart disease, the problem seems simple. Clogged arteries always involves oxidised LDL. It is the oxidisation of the LDL lipid particles that forces the macrophages in the artery walls to see it as a toxic substance and to absorb it. If the macrophages are not overwhelmed, the HDL can clean up this captured LDL material and remove it from the arteries. You have healthy arteries without any plaque buildup. When the macrophages are overwhelmed with oxidised LDL, they turn into the foam cells in the walls of arteries and die. This is the process that forms the plaque and that blocks the arteries. The thing that oxidises in LDL is polyunsaturated fats. It is not cholesterol, saturated fats or monounsaturated fats that start the oxidation. When Omega 6 polyunsaturated fats oxidise, the first step is they become a peroxide, and peroxides can oxidise anything. Polyunstaturated fats only come from the diet, and you only need a small amount in the diet. A few grams a day. You do not need or want LDL lipid particles crammed full of Omega 6 polyunsaturated fats unless you really enjoy the thrill of taking statins and the fun of visiting cardiologists.Pasture fed beef fat is 2% Omega 6 and 1% Omega 3 polyunsaturated fats - almost perfect. The fats in human breast milk used to be 1% polyunsaturated fat but now it is over 10% polyunsaturated fat typically.Richard.

author: Zero999
author_rank: Super Contributor
timestamp: September 24, 2019, 04:06:22 pm
content: Quote from: amspire on September 24, 2019, 03:20:58 pmLow carb diets aren't healthy at all. They might be good if someone is living a very sedentary lifestyle, or is significantly overweight, but they're no good for healthy, active people. I've tried one before, when I was slightly overweight and it was horrible. The problem was too few calories, which messes your body up more, than too much. I suffered from constipation, poor skin condition and it eventually led be to develop an eating disorder, which took years to fully recover from and I didn't do anything drastic at the start. I followed a supposedly safe, low carb diet, but it slowly spiralled out of control.QuoteBut they emit a lot of methane, a potent greenhouse gas.QuoteI agree with this, but it is simply not possible to provide the entire world with that much meat from pasture animals, because there isn't the land available. It makes more sense to simply grow plants and eat them instead.Forget all that palaeo bullshit you've probably read. People only got fat relatively recently, long after the palaeolithic era. Look at what humans ate before the obesity epidemic and it certainly was far from a low carb diet. They did eat less meat, but also fewer processed foods and did a lot more too. If you examine the diets of those in countries with low obesity rates, you'll find they're not low carb and they have a more active lifestyle, than most people living in the US. The obesity problem is caused by lack of exercise, not just poor diet.

author: SiliconWizard
author_rank: Super Contributor
timestamp: September 24, 2019, 04:45:08 pm
content: Very low-carb diets can indeed be pretty unhealthy in the long run. If you don't ingest enough carbs, you'll be burning fat, basically liberating ketones. And too high a level of ketones can be a very serious condition.https://en.wikipedia.org/wiki/KetoacidosisSo of course, it's all a matter of balance, and sure, many people in rich countries just ingest way too much carbs. But going from one extreme to the other may be a pretty bad idea.

author: Mr. Scram
author_rank: Super Contributor
timestamp: September 24, 2019, 05:53:14 pm
content: Quote from: Zero999 on September 24, 2019, 12:56:39 pmIndividual cases may obviously vary but on the whole healthy people get old in an expensive manner. Few people grow old without needing care to just topple over.

author: james_s
author_rank: Super Contributor
timestamp: September 24, 2019, 06:11:12 pm
content: Quote from: FreddieChopin on September 23, 2019, 05:14:04 pmHere in the Northwest, it's cold, wet and gloomy something around 60% of the year and in most areas riding a bike means close proximity to cars which is dangerous. I'd much rather exercise indoors than get soaking wet outside. Another advantage of gym equipment is I can stop at any point if I get tired or something important comes up. If I'm outside on a bike I have to ride all the way back home.

author: Zero999
author_rank: Super Contributor
timestamp: September 24, 2019, 06:40:54 pm
content: Quote from: Mr. Scram on September 24, 2019, 05:53:14 pmThat makes sense. I suppose the best way to save the planet is to genetically engineer a really bad disease to kill loads of people, something like aids but with no possible treatment.Quote from: SiliconWizard on September 24, 2019, 04:45:08 pmYes, the only evidence in favour of very low carb diets, is for treating severe type 2 diabetes and epilepsy and even in those cases, it's not a long term solution.Quote from: james_s on September 24, 2019, 06:11:12 pmEach to their own I suppose. I live in Bedford, towards the south east of the country, so it's not quite so wet, but I still prefer to exercise outdoors, than in a gym, even if it's pouring with rain. I didn't mind cycling to work this morning, even though it was blowing a gale and pissing down. I just changed at work and felt fresh. In fact I prefer cool whether when exercising and took the hottest day of this year and indeed ever recorded, off work, as I didn't want to cycle in 37 degree heat. The monster heatwave last summer was a bugger, but at least it was dry heat, so more bearable, than this summer's humidity. I've tried the gym and found it boring, with my most hated piece of equipment being the running machine, which gave me motion sickness!

author: maginnovision
author_rank: Super Contributor
timestamp: September 24, 2019, 07:20:02 pm
content: I don't like to go to the gym and I can't always do what I'd like outside so I have a home gym. Rower and bike for cardio, free weights for strength training. I suppose I could rig a generator for the rower or bike but I have nowhere to store that energy. I am doing the work regardless though so it could be beneficial to store the wasted energy. Of course it'll also cause heat while I'm already hot...

author: NiHaoMike
author_rank: Super Contributor
timestamp: September 24, 2019, 11:32:28 pm
content: Back when I worked at Intel, the gym had smart exercise bicycles with USB charging for smartphones and tablets, complete with an optional app for those who like to track stats. I would have to guess they use supercaps for energy storage, since it takes a few seconds for the USB output to switch on and it remains on even if pedaling stops for a short time.What I really would like to see is a portable implementation that actually works well. In particular, newer standards like USB-PD solve the problem of how to quickly transfer the energy to portable devices.Quote from: Seekonk on September 23, 2019, 09:08:01 pmThose who are so unfit that they're unable to make 50W are unlikely to go to the gym in the first place. I built an electricity generating exercise bicycle for senior design and everyone who tried it on the demo could do more than 50W, most could even do more than 100W for at least a short time. Not bad considering the MPPT algorithm I implemented was nowhere near optimal.Quote from: maginnovision on September 24, 2019, 07:20:02 pmInstead of figuring out how to store the energy, just use it right away to turn some fans.

author: amspire
author_rank: Super Contributor
timestamp: September 24, 2019, 11:44:50 pm
content: Quote from: Zero999 on September 24, 2019, 04:06:22 pmHow long did you try it? Did you have anyone to advise you on how to fix the problems? The symptoms you are talking about are very common and very simply fixed - take more salt. When you go on a low carb diet, your body does not retain salt. 12g a day is very healthy. If you try and exist on the recommended dose of salt - under 3g in Australia, you are going to be very constipated and sick.I feel bad for you that you could not get the right help when you really needed it. Health professionals should understand low car diets and how to handle issues that can arise, but they mostly have no idea.QuoteCorrect. They do. But it is less then the greenhouse gases caused by the agriculture and transport of grains, and the manufacturing processes we put the crops through. Cropping causes serious soil degradation, and the nutrients in cropped food is continually getting worse as a result. It is about finding a balance. Like turning the land in cities currently occupied by soft drink manufactures into fields growing vegetables with free range chickens to eat the insects. The greenhouse gases from the transport of food is massive and is probably unsustainable. Just about all the manufactured food in a supermarket is unhealthy - that is a massive amount of energy wastage involved in making food. packaging and transport that we are healthier without.QuoteThe current standard American Diet is absolutely nothing like the American diet before 1900 when heart disease was almost non-existant.When you are metabolically healthy, you can eat carbs. The top traditional Kenyan distance runners eat 85% of their energy as carbs, but when they run, their respiration quotient is about 0.72 - they are burning almost 100% fat. Carb-loaded US distance athletes have a respiration quotient of 0.85 - they are only getting half their energy from fat, so they have to keep their glycogen stores topped up. The Kenyans are not using up their glycogen stores as they run, so they have plenty of reserves available for the last 2 laps. The thing is they have superbly healthy metabolisms. They do not drink soft drinks or eat manufactured foods. They don't spike their insulin during the day by eating snacks every few hours. They don't drink energy drinks. Probably 95% or more of us over 50 have become insulin resistant, and if we eat a lot of carbs, our insulin levels get way too high. High insulin is the major driving force of almost all non-infectious diseases. Doctors do not even test for insulin resistance until it is out of control. It has just become the norm and health recommendations are now based on insulin resistant metabolisms. Low carb diets is the easiest way to get both glucose and insulin levels down to normal levels.I have been low carb for 9 years, and I am only starting to get it right now. I had plateaued on my weight, but in the last 5 months I have lost 15kG and it is still going down. I am diabetic and need no diabetic medicine whatsoever. My hba1c is 5.2 and falling - well under the diabetic range and better then most people my age. I am fitter then I have been for 30 years. I am putting on muscle mass easily which is good for 63 years old. The only medication I take is for thyroid and that medication is falling. Curing diabetes is supposedly totally impossible and I am curing my diabetes. I am reducing my insulin resistance and I am making more insulin. My blood tests keep getting better and better. What you have to understand is that if I followed the recommended diet and medications for diabetes. I would definitely be on insulin injections by now and my insulin levels would be out of control. I would have had significant eye damage and would almost certainly be on the way to serious heart disease. I would have had fatty liver, which leads to fatty pancreas which further halves the ability to make insulin.

author: Zero999
author_rank: Super Contributor
timestamp: September 25, 2019, 08:14:27 am
content: Quote from: amspire on September 24, 2019, 11:44:50 pmI tried ketogenic for a month, before slowly moving to a higher carb, but still somewhat restricted diet. I doubt salt was an issue, as lots of the foods I was eating were high in salt, such as bacon. The main issue was too few calories, resulting in rapid weight loss. I hoped that after moving to a less low carb diet, I'd maintain the same healthy weight, I'd attained form very low carb, but I didn't. I continued to lose weight to the point of being anorexic, then I lost even more weight. It took a long time to recover from that.QuoteI didn't need to go on a dumb low carb diet. All I needed to do was more exercise. My diet was fine. It was just lazing around, not doing much which was causing my body to accumulate excess fat.QuoteFarmers use fertilisers to keep nutrient levels high, otherwise crops won't grow. Unfortunately that causes other problems for the environment, when it enters watercourses.QuoteThat can be fixed by switching to renewable energy sources and forget feeding insects to chickens, just eat them instead.QuoteWhich was far from low carb.QuoteI call bullshit on this. The Kenyan athletes can't be burning body fat, because they have a very low body fat percentage. They fuel their running with carbohydrates, like the US athletes do. They're better at running because of their genetics.QuoteExercise avoids insulin resistance. Someone who's fit and healthy can better tolerate processed foods such as energy drinks, because they have a good insulin response and it gets burnt off fairly rapidly.QuoteNot everyone needs to lose weight. Would you recommend low carb to someone who's already a healthy weight?QuoteWell good for you. I know low carb can be good for diabetics, but it doesn't mean it's what everyone should be eating. Lots of medical conditions have special dietary requirements, but it doesn't mean they should be followed by those who are healthy.

author: amspire
author_rank: Super Contributor
timestamp: September 25, 2019, 09:41:49 am
content: Quote from: Zero999 on September 25, 2019, 08:14:27 amThe numbers I mentioned on the Kenyans are from a published study by Dr Stephen Phinney. I think this was probably done around the 1980's.What do you think happens when you have a big low carb meal. An athlete could easily eat well over 6000kcal a day. Some of it can go to glycogen but you can only store about 2000 kcals of glycogen in total. The rest goes to fat. When you eat a high carb meal, you insulin levels goes up and that puts the body into fat storage mode. The body turns carbs into saturated and monunsaturated fats. The thing the Kenyans have done is they are eating their own natural grains and not processed foods. They haven't put their body into a mode where carbs are the preferred source of energy. You are born in a state of ketosis, and children can go into ketosis just an hour or two after meals. It is normal for the body to be an efficient fat burner. You stay in this high fat burning mode until you put your body through a sustained period of weeks where your carb inputs are high enough to prevent fat burning. You body actually switches to a carb mode where it forgets how to burn fat properly. When you hear doctors say "Carbs are the body's preferred energy source", they are talking about people who have switched their bodies to be carb dependant. For me, my body will burn fat and ketones preferably, but I can still burn carbs as well if I need to. If some people go without carbs for say half a day, they can actually get the shakes and feel bad.Even if I did go back to carbs, I would still want to leave my body in an efficient fat burning mode - fats is the bodies primary energy storage, and it is stupid if you cannot access all that energy. If you cannot burn it, you just get fat.I love it that I can eat when it suits me, and I can not eat for a week without any hunger pangs, shakes, muscle weakness, headaches, muscle loss. I have over 300,000kcals of energy stored and my body switches to it seamlessly anytime I want. If I am travelling, I don't have to eat the dodgy meals on the way if I don't want to. I think it is great to never have to worry about where the next meal is coming from.QuoteI would recommend it to anyone who is insulin resistant. Trouble is, doctors do not test you for insulin resistance. If you can get a fasting insulin test, if it is over about 8, then you are insulin resistant. If you have a hba1c over 5, you are probably insulin resistant. The thing is if you are insulin resistant and you are eating a lot of carb, you become vulnerable to all the diabetes diseases - heart attacks, eye problems, circulation problems, visceral fat and fatty liver, cancer, autoimmune disease, dementia. There are literally hundreds of diabetes neuropathies.If you are not insulin resistant and you are eating processed food, lots of sugar and fructose, lots of white flour, and are using polyunsaturated vegetable seed oils, then you almost certainly will become insulin resistant at some point. Once you are insulin resistant, it is very hard going back again.There are very many young and totally fit people who love the low carb or ketogenic diet. If you are a distance athlete, I think it is the only way to go. Carb loaded distance athletes have to try and eat while they are running that is very uncomfortable, and eating two dozen energy bars in a day is really bad for your health, no matter how fit you are. That is what some of the carb-loaded distance athletes take with them.If you are on a keto diet, you never "hit the wall". You do not physically crash due to low glucose. You can get totally exhausted, but that is not hitting the wall. Normal people go into a coma if their glucose goes below about 3 mmol/L (48mg/dL in the US numbers). If you are in ketosis, your blood sugar can go down to below 1 mmol/L and you have no mental issues. You do not fall into coma. Your body does not shut down.On a low carb or ketosis diet, the body recovers much quicker, and so athletes can train hard for more days a week without a problem. Many athelets who still compete on carbs are now using a low carb diet for their training. You do not get as much muscle pain burning ketones as ketones in particular is the energy source that generates the fewest oxidant by-products. It is a very clean burning fuel for the body - much cleaner then glucose, and a little bit cleaner then fat.Richard

author: Cyberdragon
author_rank: Super Contributor
timestamp: September 25, 2019, 01:06:26 pm
content: Yes, there was a KS/Indiegogo scam for a generator bike a while ago.

author: Red Squirrel
author_rank: Super Contributor
timestamp: September 25, 2019, 05:44:58 pm
content: I've humoured experimenting with that in small scale. Stationary bike with alternator + SMPS that can generate a specific current (adjustable on bike) hooked up to the battery bank of a UPS or other load. You could then add power into the system but not necessarily the full current it needs.At least in theory. Not sure how realistic it would be. Like say the servers are drawing 300w, and you go pedal and try to keep up with 300w, how hard would it really be to pedal? But say you could do 100w it could at least extend the run time a bit. The key would be to be able to adjust the current, and the custom SMPS would do that. Kinda like a MPPT controller I guess. Actually you could maybe take a wind turbine MPPT controller and hook it up straight to the output of the alternator. (this would be a basic alternator with no regulation, just magnets moving near coils and everything rectified to DC)In an off grid setting it could be interesting too, setup a mini gym in the battery room and do your work out at night when the sun is gone to add a bit of energy to the batteries. Or in the morning. I know myself I'm always super cold in the morning and in an off grid setting the morning would be when you have the least amount of energy in your batteries so if you can pedal to add a bit of energy into them you would get a workout, warm yourself up before your shower, and make up for any energy usage from the bathroom lights or fan etc while you shower. Or not? Of course in the morning yourself you won't have much energy either.

author: Zero999
author_rank: Super Contributor
timestamp: September 26, 2019, 10:18:00 pm
content: Quote from: amspire on September 25, 2019, 09:41:49 amI haven't read the study, but going from what you've said it's not very low carb, but more moderate. Nevertheless, I would imagine considerable progress in sports science has been made since then.QuoteThat's because you're diabetic. A healthy body has no problem burning fat when necessary. I managed to burn fat, by eating normally and increased exercise levels, but that was only after I reversed all of the damage done by low carb, well most of it. Some of the damage has been permanent, such as reduced sensation on my right bit toe, due to neuropathy.On low carb I lost weight too quickly. At the start, my BMI was around 27. I got to a BMI of 25 within a month on a ketogenic diet. Over the next two years, on a more moderate diet my weight plummeted further. My diet gradually became more restricted again, with more fasting, until my BMI dropped to 16.5, at which point I realised it had gotten out of hand and I sought professional help. I did manage to recover, but it wasn't easy. I discovered it was impossible to eat normally. I either starved or binged. Eventually I just binge ate, consuming well over 8000Kcal on some days, most of it processed crap. Even then it took a couple of years for my eating to return to normal and I had to take antidepressants and see a therapist. The interesting thing was my weight only went a little above what it was before the low carb diet, so even after eating all that nasty sugary junk food, I was only a little fatter than I was at the start.The final stage of recovery, involved me getting fit, focusing more in health, rather than weight, without obsessing about my diet. When my eating patterns eventually stabilised and my weight stopped yo-yoing, I started exercising more. I gradually built up my fitness, whilst eating healthily and lost weight very slowly. I did need to eat extra calories to fuel my exercise, but I still lost weight. I plateaued and BMI has been around 23.5 for the last couple of years. I do eat some junk food, but it's only a small part of my diet and restricting it would affect my mental health, so would be a bad idea. I'm also aware of the fact that exercise addiction can also be a problem and it was part of my eating disorder, so I make an effort to take time off to relax, every now and then.QuoteThat's not healthy. Even if you're considerably overweight, your body can't store all the nutrients it needs. Fasting for long periods results in muscle loss, irrespective of whether it's noticeable or not. It's true fat will protect it protein so some extent, but there's a limit. Then there are all the essential electrolytes, vitamins and minerals which can't be stored and become depleted quite quickly.I recall experiencing a similar thing, whilst dieting. I'm not surprised you've experianced some distorted eating, irrespective of whether it's clinically significant enough to warrant a diagnosis or not. It's inevitable after following such a restrictive diet for a long period of time. I suggest you look up the Minnesota starvation experiment. Whether you want to admit it or not, it's almost certain you'll be experiencing some of those symptoms, even if you still have plenty of fat reserves left.https://en.wikipedia.org/wiki/Minnesota_Starvation_ExperimentQuoteThat's a bit of an exaggeration and it's not completely correct. Yes, processed foods increase the risk of insulin resistance, but it's hardly a certainty. It's similar to drinking alcohol resulting in an increased risk of liver problems. Polyunsaturated vegetable seed oils are also very healthy. There's lots of misinformation pushed by the low carb squad, which contradicts this, but it's not true at all.QuoteWell most people aren't distance athletes and ketogenic diets have been proven to cause all sorts of health problems, so it's not good at all. It's something the human body does when it's starving, rather than the default mode of operation. Distance runners won't be in ketosis all the time. They might enter it during a long distance race, but they'll soon return to carbohydrates in the following days.https://en.wikipedia.org/wiki/Ketogenic_diet#Adverse_effectsIn countries with low obesity rates, no one is on a ketogenic diet, unless they have no choice, due to famine or all they can get is meat and fish, during the Arctic winter. It's not a long term diet in any country with a healthy population. Look at Japan, as a classic example. They get most of their energy from rice and protein from healthy tofu and fish.I didn't want to go into rant mode, but you posted some very dangerous weight loss tips and I felt compelled to respond, because I don't want others to follow. I take it you're not a physician or dietician, so suspect Dunning–Kruger effect is at work, which seems to be quite common amongst dieters and fitness fanatics. I can't say I'm an expert on nutrition. I just know that ketogenic diets are bad for the majority of people, especially in the long term. A viewpoint which is backed up by mainstream science.

author: DenCraw
author_rank: Contributor
timestamp: October 01, 2019, 01:16:08 pm
content: Quote from: Zero999 on September 26, 2019, 10:18:00 pm

author: Zero999
author_rank: Super Contributor
timestamp: October 01, 2019, 04:23:45 pm
content: Quote from: DenCraw on October 01, 2019, 01:16:08 pmIt isn't clear whether that statement is aimed at me, or not, but that was my point:I know I'm not competentenough in the area of human physiology, so I prefer rely on the scientific consensus that low carb diets, especially extreme ones, are not good for you. I'm aware some people have tried them and claim they've had positive effects, but many people say the same about all sorts of treatments with very little scientific support/reasoning behind them. The problem is there is a lot of information out there which can be dangerous when people who lack the relevant experience and background education access it. This is akin to someone who's read a bit about electrics on the Internet doing their own wiring: the end result is more often than not a very dangerous mess.I hope you understand why I was triggered, as I've struggled with this myself in the past, but sorry for going off on a rant.To answer the original question: it might actually be worthwhile to harvest some energy from humans in a gym, but expecting it to become a net power generator is optimistic. Flicking back through the thread:Quote from: martin1454 on September 24, 2019, 07:14:02 amYes, that makes sense, it's not much but might help offset the energy used by the gym in cooling/heating (if it's using a heat pump) and lighting.Quote from: NANDBlog on September 24, 2019, 10:09:38 amThe figures you've given make sense, but why have you concluded it would be a huge waste of energy an resources?Your figures are for one generator on one bike, vs a solar panel. How much more or less expensive is the generator vs the solar panel? I'd be surprised if it costs more than the solar panel. Another thing to bear in mind is the generators on the bikes will produce electricity, even when it's dark and cloudy, which is when more people are likely to be using the gym.You could be right: it might not be economically viable, but I think further analysis is required before jumping to any conclusions.

author: Siwastaja
author_rank: Super Contributor
timestamp: October 01, 2019, 05:07:17 pm
content: Weight loss "tips" are by definition a total scam and as a concept, extremely dangerous way of thinking. Yet so widespread.Special weight loss diets are simply just not needed.Low carb fad has a very strong basis in the fact that the "official story", at least here, overemphasized the carbohydrate intake and was scaremongering about the fats while not giving proper warnings about sugar. Low carb fad is a counter reaction to this.The answer is normal human food, nothing more. But if you are living in a culture or subculture which has completely lost the sense of what that means, you need to do some homework, and it'll be difficult with all the "diets" out there.After starting to eat normal human food in a sustainable way, and stopping taking excess shit (especially sugar drinks), the body weight starts to change towards the equilibrium weight. The equilibrium weight is mostly defined by the calory intake (in proportion of body size), secondarily by amount of physical excercise, and tertiarily by fairly small personal differences.This means, you just need to change your habits to something sustainableyou will follow for your entire life. I.e.: no special diets. Never.The problem with special weight loss diets is, you are very likely to change back to the old habits, becauseyou did not even try to recognize and solve the problem.A seriously overweight person automatically starts losing weight at a very high rate when they start to eat normally. Sometimes, you may even need tolimitthe rate;notspeed it up using a special "weight loss" trick diet!If the weight loss rate is really insufficient, you are still eating wrong and need to fixthat. This is the only way you'll find the sustainable normal diet for your whole life.Fixing the very last small amount of overweight is going to take the longest time, since it's an asymptotic decay. OTOH, it's not a serious health issue and doesn't require action.My lifestyle change 5 years ago was enough to cause weight loss from 136kg to 110kg in less than 6 months, the highest rate of drop was somewhere around 1.5kg/week, andI was never on a weight loss or low-calory diet. There were absolutelyzeroweight loss tricks involved. I just stopped drinking sodas almost completely, and started preparing my own food from basic ingredients, including a lot of vegetables. After first 6 months, the rate slowed down, and my equibilirium, which has been kept since, is at about 106kg. Further decrease would require significantpermanentchanges in amount of food consumed. (I'm 190cm and quite large, so about 106kg is quite acceptable and not an imminent danger, although a bit too much still.)As for the original question, you could maybe harvest about 30-50W on average from the bike at the gym, assuming they have 100% occupancy (duty cycle). With 50% occupancy and 10 hours/day, this would be around 70 kWh/year, worth approximately $10. Considering the difficulties in storing the energy or injecting it to the mains, the payback time would be very long or possibly infinite.If you have a special case of a gym where strong athletes run multiple bikes all day long, then maybe!