Also, without significant calories in the bottle, athletes can focus on optimal hydration. While temperature does not significantly affect fueling demands for an event, it most certainly affects hydration demands. By keeping nutrition and hydration separate, you can more effectively address both needs.
The Cons: The biggest downside of this approach is the need to carry solid foods while training and racing. It's impractical to carry enough food for an entire Ironman so athletes often have to refuel with what's available on the course. Sports gels, drinks and powders are popular for a reason: they are convenient and they can be found on most racecourses. While they may not be perfect, some fueling is better than no fueling and these products are easy. Coaches recommend their athletes actually train with these on-course products so they can get used to them before the event.
Another downside is potential stomach cramps that creep up while chewing food on the run. While it's relatively easy to fuel on solids on the bike, it's difficult to ingest the same amount while running without feeling any repercussions. As most of you can attest, trying to run too soon after a big meal and you'll experience cramps and even nausea. The energy requirements of running combined with the constant jostling stress the stomach and its digestion too much. A high-calorie bottle provides the energy needed while minimizing stomach cramping and digestion.
Significant variability exists between athletes. Some do quite well on snickers bars and coke (one of my personal favorites), while other guts are quite sensitive to even the slightest changes.
A high-calorie, high-concentrated bottle is convenient, making it easy to deliver the much-needed calories while racing and training. It's also relieves the digestive system when chewing becomes difficult. Plus, gels, drinks and powders dominate most aid stations at long triathlon events, making it a virtual prerequisite for athletes to fuel on them just so they can get used to what's being offered on race day.
Unfortunately, it's all too easy to surpass the gut's absorption ability with this strategy. This can cause serious backup, resulting in tough GI issues and even dehydration. This can have more serious consequences in hot and humid environments when the hydration demands are especially high.
On the other hand, athletes can more optimally address both their hydration and fueling demands by keeping them separate. While some sloshing may occur, this digestive process helps ensure that you don't flood the small intestine with more calories than it can handle. By drinking lower concentration fluids, the body can more easily absorb the fluids with minimal backup and less dehydration.
Regardless of the strategy you employ, it's important to be aware of the pitfalls of both. If you fuel and hydrate with high-calorie bottles, be careful not to take in too much at any one time. If you fuel and hydrate separately, be sure to pick foods that you can chew and digest easily.
Practice, refine, and revisit your approach constantly. Nutrition should be part of your training regimen. If you do experience GI issues while racing, it's safe to say your approach could use some tweaking. You'll also want to modify your strategy depending on the duration and type of event or training session.
Your approach will continue to evolve and change as you mature as an athlete, especially as you start pushing harder for longer periods of time.
And while every athlete is different, it's still worth finding out what works for others and experimenting with those methods yourself. Just don't tweak anything too close to your next race.
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