How fitness and metabolism change in your 30s vs. your 20s

This is something that I’ve occasionally been pondering: how fitness and metabolism change as we age.  I feel like it’s so common to hear friends say that they used to be able to eat anything, but now they have to watch their food intake.  Or, they feel like they have to work harder at the gym than they ever have to maintain their strength and muscle definition.  At the same time, I know so many women that I think are more fit in their 30s than their 20s.  I also know some super fit and lean 40 and 50-year olds.  What’s their secret?  Why does this happen? 

So, of course, I put on my detective hat and got down to researching. 

How do hormones change in our 30s? 

Our basal metabolic rate decreases by one to two percent per decade, according to the American Council on Exercise.  To offset this, we can either move more (to burn more calories), eat less (decrease calories slightly to account for lower BMR), or strength train and focus on lean muscle building (more muscle burns more calories at rest than fat).  We all know my favorite option is #3. 

DHEA (dehydroepiandrosterone) is a hormone produced by our body’s adrenal glands.  It peaks in our 20s and decreases in our 30s.  This can lead to a slower recovery time and increase in body fat.  Low DHEA can negatively affect our energy, mood, and sex drive. 

Your body starts to produce less HGH (human growth hormone) in our 30s, which can also (surprise) impact our metabolism.  SO many reasons to strength train! 

How do fitness levels change as we age? 

Fitness levels don’t have to necessarily change dramatically as we age. ( I think it’s a slow shift to decrease in intensity and impact as we age, but that could be more out of preference than necessity.)  The biggest impact will be caused by the decrease in muscle mass.  We can lose strength, and with less muscle on our frame, our metabolism decreases.  We can also be impacted by changes in balance and energy levels; things that used to feel good may not feel the same way. 

For myself, I’ve noticed that I don’t crave high impact exercise as often as I used to.  I used to feel like I needed to run, sprint, and jump almost every day.  Now, I still incorporate these things into my routine, but it’s on a less frequent basis.  I’d rather go to Orangetheory once or twice a week instead of every day.  Also, worth mentioning, I don’t think it’s a good idea, in general, to do OTF every day.  Your heart is a muscle and needs rest and recovery to become stronger/more efficient.  If you’re working it to its max every day, it doesn’t have enough time to recover, and you could also be affected by injury from repeated movement with muscle imbalances/compensation, burnout, and diminishing returns. 

I feel like there’s a huge benefit to getting older with our workouts/fitness: we have a stronger mind-body connection.  I think that as we learn more about our body and our fitness levels, it becomes easier to really focus and tune into muscle groups when we’re training them and emphasize proper form.  When I was in my early 20s, I just wanted to get in a killer workout.  Now you’ll find me breathing, squeezing my glutes, and pulling my core in for so many of my exercises.  Older = wiser. 

How can we continue to be more fit even when it feels like the odds are against us:

– Focus on proprioceptive exercises.  Proprioception is our body’s ability to recognize where it is in space.  By training this skill, we can help to prevent falls as we age and also challenge deep stabilizing muscles.  Find ways to add a balance challenge into your routine!  Stand on one leg for your biceps curls, try single-leg step-ups with a knee up at the top, hop from one foot to another and hold, practice yoga!  There are 4 exercises you can try in this post. 

– STRENGTH TRAIN. ( I’m yelling because it’s important.)  From reading all of the info above, we can conclude one thing: strength training can save us all!  This is an easy way to combat so many of the effects of aging.  Pick up those weights and challenge your strength. ( Need a beginning strength routine?  Check out this one!) 

– Do the things we enjoy and that feel good; truly listen to our bodies.  Emphasize consistency.  If we do the things we enjoy, we’ll be so much more likely to stick with it.  There’s a good chance that our preferences will change over time.  Lead with your heart and don’t be afraid to change your routine if this means you’ll stick with it. 

What have you noticed about your routine over time?  What’s one of your fitness goals for the next 10 years? 

My main goal is to continue to make movement a part of my life.  Even if I don’t get in an official workout, I try to move as much as I can during the day and hit my 10k steps. 

14 Comments

This is an odd one but I find that my feet have changed so much in the past year or so.  I have to wear more supportive shoes while just being up and about.  And my feet tend to ache after a day of movement and working out.  What shoe do you recommend for strength training?  I need to get a new pair of tennis shoes and need them to work for strength training and my cardio days bc of budget.  I used to be able to just grab whatever tennis shoe was on sale but I don’t think that’s realistic anymore. 

I was just pondering this yesterday!!!  I didn’t feel like doing a “hardcore” sweaty HIIT workout..(although I love them..) I was tired and a little stressed mentally.  So I opted to listen to my body and ended up doing a dumbbell workout for the upper body for 45 minutes! (  I said I was gonna do just 20 minutes- lol) but it was therapeutic and just what I needed.  I think we have to listen to the needs of our bodies and push when we need it but also know when to back off & slow it down. ? 

I love everything about this post!  I swear the day after my 35th birthday my body said “whoa hey, didn’t realize we were here yet, let’s send our metabolism into the toilet”…haha…it’s been a rough year weight gain wise…I haven’t quite hit my new normal yet!  And yes, the HIIT workouts I used to thrive on have not been feeling all that hot for me anymore.  Thanks for the suggestions to changes of routine…I especially like the note about “emphasize consistency” – lower impact/mind body/gentle strength training every day is something I’m much more likely to stick with than trying to schedule a week of higher impact workouts and not doing them! 

Thank you for this post!  This is something I’ve struggled with after turning 30 – I’m definitely in the “I can’t eat the same way I used to” group.  After a year of trying to lose weight gained during grad school, I went to a naturopathic doctor and was diagnosed with adrenal fatigue.  From what I’ve read, you should avoid high-impact workouts if you have adrenal fatigue.  I’d be interested to hear from anyone who has experienced adrenal fatigue and what workouts worked for them! 

Would you like to make this a regular series or perhaps a regular topic on the podcast?  Because this is so much what I am struggling with/ have struggled with / and may continue to until my kids are older.  This is my struggle bus.  I really enjoyed the post and the research put into it.  Thanks for your hard work. 

Excellent post!  I agree with you on the strength training and balance training.  Especially as moms, we have to make sure we’re getting strong on both sides of the body, with all of that baby carrying and pushing one hip to the side.  I think mobility is also very important, as bad movement patterns continue to get worse we get older.  Overall, just keep moving!  🙂

I love this post!  I’m getting close to 40 and I ha e three kids ages 8 to 18 months…I definitely want to stay healthy and strong for them but as I get closer to 40 it’s getting harder to lose body fat for sure.  I lift on a regular basis but could probably up my weights.  I second the podcast request!  It would be a great one

I have DEFINITELY noticed in my 30s that I can’t skimp on warming up and stretching.  I’m dealing with a host of injuries right now and I have for about 6+ months that I think are a result of not taking enough recovery days and not taking care of my muscles.  I’m now trying to create habits that involve more mobility and yoga! 

Great post!!  I work with a lot of younger nurses and I tell them all the time that my 30’s have NOT been kind to me!!  I haven’t exactly helped the situation much until recently, but man it has been an adjustment…. 
I 100% agree that strength training is the key to combat the toll that age takes on us! 

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