Author: Steve Born
When exercise goes beyond two hours, we generally recommend that athletes use a “carb + protein” fuel (Sustained Energy or Perpetuem), either as their sole fuel from beginning to end, or as their primary fuel (roughly 2/3 – 3/4 of the time). The reason for this recommendation is that once you hit that second hour and beyond, a small percentage (roughly 5–15%) of their energy requirements will be fulfilled from protein. If you don’t provide some in the fuel mix, at least part of the time, your body has to cannibalize the lean muscle tissue to obtain the amino acids it needs to fulfill that small percentage of its energy requirements.
The last thing you want to do is have your body literally digest its own muscle tissue to make fuel. One reason is the increase in fatigue–causing ammonia; there is no doubt that excess ammonia is a primary culprit—perhaps THE primary culprit—in premature fatigue during endurance events. The other reason is that you’ll have broken down a greater volume of muscle tissue, which will prolong recovery time. So again, generally speaking, when exercise goes beyond two hours, we recommend that athletes use Sustained Energy or Perpetuem, either as their sole fuel from beginning to end, or as their primary fuel (roughly 2/3 – 3/4 of the time), with Hammer Gel or HEED used to augment that. If it’s a really long bout of exercise, a Hammer Bar on occasion would be perfectly acceptable.
Things may (key word “may”) be a little different come race day. We believe that a race that’s in the 2–3 hour range, perhaps just slightly longer, is in a “gray area” so to speak, which means that you can use either a “carb + protein” fuel (Sustained Energy or Perpetuem) or a “carb only” fuel (HEED or Hammer Gel). The selection needs to be based on the following:
- The type of race that you’re doing. For example, running is a more impactive and thus a more “digestively challenging” type of exercise than cycling.
- The intensity of the effort. It’s a lot easier to digest calories when the pace is more relaxed, which it usually is during a training session rather than during a race. That’s why, in the “10 Biggest Mistakes” article, we suggest having a fueling game plan but to “write it in pencil, not in ink.” What is meant by that saying is that caloric intakes that worked during training may not be appropriate during a race; you may need to consume slightly less in a race than you did during training. Increased anxiety, increased pace, and increased potential for dehydration all contribute to the possibility of a less–than–optimally–functioning digestive system. In addition, at the increased pace during a race, more blood is diverted from digestion and directed toward maintaining muscle performance.
- The weather and how well or poorly you’re acclimated to it. The hotter the weather, the more compromised the digestive system becomes. During hot–weather racing, athletes usually find that they need to increase their water and Endurolytes intake while lowering their calorie intake.
- The terrain. For example, doing lots of climbing while on the bike or during a run usually diminishes digestive capabilities somewhat.
Our belief is that if the race is going to involve high intensity right from the gun, and/or if the weather is going to be very warm–to–hot, and/or if other factors such as hilly–to–mountainous terrain come into play, deference should be given to the fuel that is the quickest to digest, and that means HEED or Hammer Gel. Yes, some ammonia will be produced during the effort by not providing the body with some protein along with the carbs. However, if the race is in the 2–3 hour range—and perhaps just slightly longer—it will be over long before the issues involved with ammonia accumulation truly become problematic.
Once again, in general we recommend a “carb + protein” drink (Sustained Energy or Perpetuem) when exercise goes beyond two or so hours. However, come race day— when a lot of variables need to be taken into consideration—you have a lot of options to choose from when the race is in the 2–3 hour range… you need to go with the fuel that makes the most sense, based on the above–listed factors/ variables. If those factors do come into play, we recommend the use of Hammer Gel or HEED for a high intensity race that’s in the 2–hour to 3–hour range. If you know you’re going to be out there for more than three hours we believe your body is going to perform a better if Sustained Energy or Perpetuem is used as the primary–to–sole fuel.
All this said, this is not meant to be a “set in stone” rule. Everyone is different so your fuel selection may be different than another athlete’s. The earlier–listed information is just a suggestion for you to consider when doing a race that is 2–3 hours in length – the “gray area” of fueling.
Excerpted from the article, Proper Caloric Intake During Endurance Exercise