HEED is a “carbohydrate only” drink mix that is great for bouts of exercise up to 2-3 hours in duration. Perpetuem is a “carb + protein + healthy fat” drink mix that is ideal for longer-duration workouts and races. The inclusion of protein in Perpetuem helps to satisfy the 10-15% of energy that must come from protein/amino acids during long-duration exercise. Without this protein donation the body is forced to cannibalize its lean muscle tissue to satisfy this small percentage of energy requirements. That decreases exercise performance, due to the excess amount of fatigue-causing ammonia that is produced, and it will also cause recovery after exercise to be significantly longer because there is a greater percentage of broken down muscle tissue that needs repairing. The healthy fat added to the Perpetuem formula gives the body a cue of sorts to let it know that it’s not depriving it of fat (the “you have to eat fat to burn fat” train of thought). As a result, the body releases its fatty acid stores more liberally so that the calories from them can be used to create energy more consistently and efficiently. As you can see, Perpetuem is a very complete “meal in a bottle” fuel for endurance exercise.
I love how Perpetuem works; however, I do not like to drink large volumes of flavored liquid hour after hour. Instead, I’ll make Perpetuem in a bit more-concentrated, multi-hour bottle, and I typically make a 4-hour bottle. I weigh ~200 pounds, so I personally use 1.5 scoops an hour, which supplies 202.5 calories, an amount that works well for larger athletes (190+ lbs.) Lighter weight athletes will find that 1 scoop (135 calories) to 1.25 scoops (168.75 calories) on an hourly basis works well. Again, though, instead of making a bottle each and every hour, I’d make one bottle that contained 6 scoops of Perpetuem. What I do is start with the bottle about 1/3 filled with water. I then add a couple of scoops, but the lid back on the bottle and shake vigorously. I repeat the process until I have my 6-scoop bottle completed. Now I have 4 hours of fuel in one bottle, which benefits me in two primary ways:
I don’t have to drink so much volume of flavored liquid hour after hour. Because I have 4 hours’ worth of fuel in one bottle, I only need to drink ¼ of the bottle every hour, augmenting that with plain water from another source (another water bottle, hydration pack, etc.) to take care of my hydration needs. I find that plain water quenches my thirst better than liquid fuels do, and drinking water to cleanse the palate makes taking another drink of fuel even more palatable.
Because I have 4 hours of Perpetuem in my bottle, I don’t have to stop and make more every hour, which saves me time.
A lot of athletes prefer using Perpetuem this way and it really does work well and save time. Using a Sharpie permanent ink pen, you could even mark your bottle off into 4 equal segments so that you’d have a visual of what line you need to drink down to every hour.
Perpetuem Solids is the exact same formula as Perpetuem in the powder drink mix. However, it takes 4 chewable tablets to equal 1 scoop (135 calories) of the powder version. You could use Perpetuem Solids as your sole fuel but that would require a lot of chewing. For me, I’d need to chew 6 Perpetuem Solids tablets per hour to meet my calorie requirements, and I personally think that much chewing would wear out my jaw. As such, I use Perpetuem Solids more as a part-time, fill-in-the-calorie-gap fuel… I don’t ever use it as my sole fuel.
That said, what a lot of athletes will do—and this is a completely acceptable option to provide a little variety in the menu—is to use 2 Perpetuem Solids + 1 serving/packet of Hammer Gel on the occasional hour. The solids will give you just about 67 calories, and the serving/packet of Hammer Gel will supply 90 calories. 167 calories per hour is the “sweet spot” for an awful lot of athletes.
Another option is to consume 2 packets of Hammer Gel to cover one hours’ worth of fueling needs, with one or both of them being one of the protein-containing flavors: Peanut Butter, Peanut Butter-Chocolate, or Nocciola (Hazelnut-Chocolate).
Bottom line is that I’d personally be using a multi-hour hour bottle of Perpetuem to cover most to all of my fueling needs. And if I needed a little variety in the menu, I can go with just Hammer Gel for an hour, or a Perpetuem Solids + Hammer Gel combination.
Lots of options and they’re all completely acceptable and highly effective.