The above quote exists on the back of my friend John?s shirt. He created some team t-shirts for his crew to wear while supporting him on his first 100 mile endurance run this past year. While I hate to burst John?s bubble, being awesome alone can only get you so far in a 100 mile run. As many of his crew would attest, I?m sure he ate ate and drank some serious calories along the way to this impressive feat.
Often viewed as the fourth discipline in triathlon, athletes must find a nutritional plan that will get that athlete to the finish line in the fastest way possible . This plan must balance the athlete?s hydration and fueling requirements. And given the astonishing number of athletes who self report GI distress during races, it appears that many athletes do not have their nutrition and hydration plan dialed in.
This article compares two popular fueling methods triathletes use while training and racing: chewing calories versus drinking them. Before comparing the relative merits of the two approaches, it will provide some scientific background on why we need to fuel and hydrate and what can go wrong when we do not meet these requirements.
To begin, a degree of consensus exists among coaches, exercise physiologists, and nutritionists: for training sessions and races that extend beyond two hours, athletes should supplement with something in order to maintain their performance output. Awesome alone doesn?t cut it. After all, the body?s muscle glycogen storage capacity is limited, and glycogen is our energy storage for glucose?one of the preferred sources our muscles use to make ATP for energy.
When an athlete?s glycogen stores drop too low, they experience significant fatigue and a sharp decrease in performance. In its most extreme form, athletes ?hit the wall? or ?bonk?. So athletes bring additional fuel in the form of energy drinks and bars to provide a ready energy supply to continue training and racing at their best.
But eat too much or at the wrong times and athletes experience other types of complications in the form of gastrointestinal (GI) problems (stomach aches, nausea, etc.), which can slow athletes down even more. So if athletes do not consume enough fuel, they experience early fatigue and a decrease in performance. If athletes consume too much fuel, and their gut slows down and rebels.
On top of fueling, athletes need to hydrate to perform. ?Let?s highlight two of the ways dehydration negatively affects the body. First, as blood plasma depletes due to dehydration, our heart?s stroke volume?the volume of blood pumped per heartbeat?diminishes. Due to this reduced cardiac output our heart has to pump faster just to deliver the same number of oxygenated blood cells to our working muscles. This phenomenon is known as cardiac drift and reflects the additional stress heat places on the body. Anyone who has experienced an elevated heart rate that stays way above their effort level has experienced this phenomenon.
Second, dehydration compromises our body?s thermoregulatory response and ability to stay in homeostasis. As part of our body?s cooling mechanism, we take advantage of pulling heat from the body through sweat evaporation. We also cool through the principals of convection (dispersal of heat through blood circulation) and conduction (body heat radiating away). Our blood vessels vasodilate?expand?to allow additional blood to circulate into the superficial capillaries in the skin to pull heat away from the body by means of the above two methods. Without taking on additional fluids, our bodies can only perform for so long without purposely slowing down to protect our vital organs from overheating. It?s generally recognized that we can tolerate up to a 2-3% loss in body water and still perform, but beyond that we develop headaches, dizziness, nausea, disorientation, and sluggishness to name a few of the minor symptoms.
Ultimately, athletes need to balance the twin perils of glycogen depletion and dehydration to perform at peak levels in events lasting longer than 2-3 hours, and especially in hot and humid conditions. For hot Ironman events such as Kona, it?s imperative to nail down a solid nutrition and hydration strategy. So let?s compare two different fueling strategies to see what?s best for you.
DRINKING: the super calorie bottle
The first fueling method tackles our fueling and hydration needs at the same time. These bottles usually contain a mix of mostly carbohydrate (some with additional fat and protein) and are specifically targeted for the 2-3 plus hour events with greater fueling requirements.
The Pro?s:
Athletes can conviently fuel and hydrate at the same time with these sports drinks and powders. This makes it easy to grab and go when constantly on the move training and also while racing. Chewing solid food can also slow the digestive system down. Drinking those calories is an alternative way to get them in, especially for athletes who deal with stomach cramps ?If done correctly, athletes can meet their fueling requirements while also tackling some of their hydration requirements.
The Con?s
Some people in the endurance world believe that these high calorie bottles are responsible for the majority of GI issues experienced by racers, and they offer compelling evidence in support. As it turns out, the rate at which we should hydrate is different from of the rate of fueling, making it unrealistic for one product to optimally address both.
In this case, it can become way too easy to slurp down large amounts of calories that far surpass our gut?s ability to handle them. When looking at our gut and its absorption ability, it?s best to think of the gut as a tollbooth and the fuel (in this case carbohydrates (CHO)) as the cars passing through. On any given day, cars (CHO) must stop to go through the tollbooth (gut). During regular traffic hours, the gut can more than handle the amount of carbohydrates coming its way with minimal backup.
Now picture this tollbooth during rush hour traffic. The rate at which carbohydrates show up far surpasses the rate at which the gut can process them, contributing to a nasty build up in traffic. Since the gut cannot double its rate of absorption, athletes experience stomach cramps, bloating, and nausea when ingesting too much carbohydrate too quickly. So while super calorie bottles work to get fuel in, they can be too effective, creating serious backup and GI issues that slow athletes down in a different way.
Regardless of this innovative solution, athletes still risk failing to meet their hydration requirements as the processing of carbohydrates slows down our ability to take in fluids. Simply put, with the super calorie bottle athletes are either well fueled but under hydrated or properly hydrated but way over fueled, contributing to the GI issues that so many athletes seem to experience.
Chewing: keeping nutrition and hydration separate
While the super calorie bottle does have its merits, some coaches and athletes would rather simplify their approach to fueling and hydration and minimize potential GI issues. People in this camp believe we should chew our food and focus on hydration in our bottles. Most GI issues occur when athletes combine the two and blur the edges as stated above, significantly over-taxing the gut.
The Pro?s
Chewing food slows down the rush of calories to the gut via the digestion process, reducing potential GI issues. When athletes chew solid foods, the entire digestion process slows down the rate at which fuel goes from the stomach to the small intestine, and from the small intestine into the bloodstream. Digestion in the stomach is the key regulator here. A highly concentrated high calorie bottle bypasses the stomach too quickly because no digestion is required. Athletes then run into the tollbooth traffic jam as we previously discussed, as the gut can only transport so many carbohydrates so quickly.
And as previously stated, high calorie bottles also slow fluid absorption through the gut, hampering our hydration efforts. When our body encounters a fluid that is thicker than our blood, it has to pull fluid from the body into the small intestine to dilute it to an acceptable level. This process can only help so much before it both contributes to dehydration in addition to backing up our GI system.
Finally, without significant calories in the bottle, athletes can focus on optimal hydration for the body to continue performing at a high level. While temperature does not signifanctly affect our fueling demands for an event, it most certainly affects our hydration demands. By keeping our approach to nutrition and our approach to hydration separate, we are better able to optimally address both.
The Con?s
A few downsides exist to this approach, including the inconvience of carrying solid foods everywhere during training and racing, and dealing with stomach cramps while chewing food on the run.
Sports gels and drinks and powders are popular for a reason: they are convenient and they are on most racecourses. These products offer a simple and concentrated fueling solution for busy athletes who are always on the go. While they may not be perfect, some fueling is better than no fueling and these products are easy. Furthermore, these products are the main sponsors of most endurance events. Coaches recommend their athletes train with these on course products so they become used to them. It?s impractical to carry enough food for an entire Ironman so athletes have to refuel with what is on the course.
The mode of exercise also affects the bodys ability to fuel on solid foods. While an athlete could fuel on solids on the bike just fine, 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 needed energy needed while minimizing stomach cramping and digestion.
So What?s Better?
While choosing a fueling and hydration strategy of your own, it?s important to remember that a significant variability exists between athletes. While some seem to do quite well on snickers bars and cokes (one of my personal favorites), other?s 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, and it is easy on the digestive system when chewing becomes difficult. 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 can be too easy to fuel and surpass the gut?s absorption ability with this strategy, causing a serious backup and resulting GI issues. Our body even has to dilute these high concentrated solutions just so it can absorb it back into the blood stream. This process significantly slows down our fluid absorption, which 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, our digestive process ensures that we do not flood our small intestine with more calories than it can handle. By drinking lower concentration fluids, our body can more easily absorb the fluids with minimal backup and less dehydration.
Regardless of the strategy you employ, it?s important to practice, refine, and revisit your approach all season long. And if you do experience GI issues while racing, it?s safe to say your approach could you use some tweaking. But let?s also remember that different fueling and hydration strategies are called for depending on the duration and type of event or training. ?These strategies may also change as you mature as an athlete and practice pushing harder for longer periods of time. And while it?s safe to say that everyone?s approach will be a bit different, it?s still worth learning what works for others and experimenting on yourself. Just don?t do it too close to your next race.
Train Well
?
Nate
?
See More:
- Coyle, E. F., Gonzalez-Alonso, J. ?Cardiovascular Drift During Prolonged Exercise: New Perspectives.? Exercise and Sport Sciences Reviews, p. 88. 2001. http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0CCgQFjAB&url=http%3A%2F%2Fwww.edb.utexas.edu%2Fcoyle%2Freview%2520arts%2F29%2520PR%29%2520CV%2520Drift%2520New%2520Perspectives.pdf&ei=Lm8tUOeqI8q9yQHvqIDADw&usg=AFQjCNEowwxlsT2wkP3ig4lYqrDShiwStw
- X. Shi, RW Summers, HP Schedl, SW Flanagan, R. Chang, and CV Gisolf. ?Effects of carbohydrate type and concentration and solution osmolality on water absorption.? Med Sci Sports Exerc 27(12), 1607 -1615.
- A E. Jeukendrup, ?Nutrition for endurance sports: Marathon, triathlon, and road cycling.? Journal of Sports Sciences. Vol 29, supplement 1, 2011.
- Nick Legan. ?Made from Skratch. Skratch makes hydration natural.? Velo News. http://velonews.competitor.com/2012/07/nutrition/made-from-skratch-skratch-labs-makes-hydration-natural_231775
- Greg Kopecky. ?Catching up with Allen Lim.? http://www.slowtwitch.com/Interview/Up_close_with_Allen_Lim_3054.html
?
?
?
Source: http://www.helmingathletics.com/2012/09/06/chewing-or-drinking-your-calories-whats-better/
mega upload santorum wins iowa archer ibooks 2 ifl indoor football league newt gingrich wife
No comments:
Post a Comment
Note: Only a member of this blog may post a comment.