Consuming variety of carbohydrates during exercise and eating balanced training and recovery diet improve performance
What should athletes participating in endurance and ultra-endurance
exercise eat before, during and after sports? Here the answers to these
and other questions about endurance sports nutrition:
Carbohydrates
Q. What should an endurance sports athlete eat during a long run, bike ride or other exercise that lasts more than 60 to 90
minutes?
A. It depends. Some athletes like the convenience of engineered
sports foods.
Others prefer the taste (and price) of standard supermarket foods, such
as fig bars, dried pineapple, and gummy candy. The bottom line:
all are equally effective.
And because we're talking more about "survival" rather than "good
nutrition" during endurance exercise, you don't have to feel guilty if
you use candy as fuel. Sugar (e.g. simple carbohydrates) is what your
body wants! Remember, too, that sports gels and sports drinks are also
"just sugar."
Q. Does it matter if you get your energy from an energy bar or a sports drink?
A. The short answer is no. Both solid and liquid energy foods
get burned at the same rate when exercising for more than half an hour.
So, again, what an athlete eats depends on what his intestinal tract
tolerates and what tastes best.
Consuming enough calories is more important than the form of the
calories because research suggests that endurance athletes who consume
more calories do better than athletes who consume fewer calories. (For
example, Ironman Triathlon champ, Chrissie Wellington, consumed about
335 calories/hour when she won in Hawaii.)
The challenge is to train the intestinal tract to digest that much fuel
and convert it to energy for the body to use. In other words, the
training program for an endurance athlete actually needs to include
training of the
intestinal tract as well as the heart, lungs and muscles.
Q. How much should an athlete eat to maintain good energy during exercise lasting longer than 60 to 90 minutes?
A. The rule of thumb for fueling during endurance exercise used
to be to consume 1 gram of carbohydrate per minute of exercise (e.g. 60
grams of carb per hour or the equivalent of 240 calories). The
research, originally done with just glucose, suggested that consuming
more than 60 grams of glucose per hour offered no extra benefits because
the body has a limited number of glucose transporters and can carry
only 60 grams out of the intestines into the blood and to the muscles.
Recent research, however, shows that consuming a
variety of sugars
(e.g., more than just glucose) makes more fuel available to the muscles
per hour. That's because different types of sugars (carbs) use
different transporters.
Most endurance athletes are already consuming more than just glucose: Sports drinks, for example, contain glucose
and
fructose. while a banana is made up of many different types of sugars
and uses many different transporters. An athlete's muscles will be able
to access more fuel (up to 90 g carb/hour or 360 calories per hour) if
he consumes more than just one kind of sugar.
The new research has resulted in new recommendations on the optimal
number of grams of carbohydrates to consume during endurance exercise:
Fueling During Exercise
| Exercise Duration |
Grams of Carbohydrates Per Hour |
| Less than 45 minutes |
No fueling during exercise required
(other than pre-exercise snack)
|
| 1 to 2 hours |
30 g. carbohydrates (120 calories) per hour |
| 2 to 3 hours |
60 g. to 80 g. carbohydrates (240 to 320 calories) per hour1 |
| More than 2.5 hours |
90 g. mixed carbohydrates (360 calories) per hour (sports drink,
candy, dried fruit, pretzel)
|
Some serious athletes train first thing in the morning without eating
before/during exercise. While doing this may teach the body to burn more
fat (hence spare limited glycogen stores), it's grueling and the
verdict is unclear if it enhances competitive performance. Stay tuned!
Q. What happens if fueling during exercise creates intestinal distress?
A. Consider a "swish and spit" approach. Research shows that
athletes who just swished and then spat out a sports drink performed
better than athletes swishing and spitting just plain water. How could
that be? It's because receptors in the mouth are linked to the brain so
that when an athlete's mouth gets a swish of sports drink, it sends a
signal to the brain - which then sends a signal to the body - that
energy is on the way, so it's okay to work harder.
Protein
Protein requirements are hard to define because the amount of protein
your body needs depends on how many calories you consume. That is, if
you are restricting calories, you require more protein than when you eat
adequate calories because the protein gets burned for fuel. Dieting
athletes should target at least 1 g protein/lb (2 g pro/kg).
Note: If an athlete is dieting to reduce body fat, it is hard to build
muscle mass at the same time because building muscle takes energy, while
dieting restricts energy.
The protein recommendations for non-dieters who consume adequate calories are:
- Healthy adults: 0.4 g Protein/pound 0.8 gm Protein/kg
-
Strength athletes: 0.5 to 0.8 g Protein/pound 1.2 to 1.7 g Protein/kg
-
Endurance athletes: 0.5 to 0.6 g Protein/pound 1.2 to 1.4 g Protein/kg.
Q. Does an athlete need to take protein supplements (such as by consuming protein shakes)?
A. No. Because the typical athlete's diet contains more than enough protein, most athletes do
not need protein supplements. A protein-rich food with each meal and snack will do the job.
Q. During endurance exercise, should you choose a sports drink with protein?
A. Not unless you prefer the taste; it does not offer
performance advantages over a standard sports drink. The better time to
consume protein is
after exercise because consuming carbs plus
protein (such as in a specially formulated recovery sports drink
containing protein and carbohydrates, or chocolate milk, fruit yogurt,
or spaghetti & meatballs) helps the body recover from exercise by
enhancing muscle repair and by replenishing glycogen stores in muscles,
which are a source of fuel during prolonged exercise.
2
Balancing carbs plus protein
Consuming some carbs+protein before a workout, as a part of a
pre-exercise meal (cereal+milk, fruit+yogurt) is another option to
bolster the supply of protein available both during and after exercise
for recovery.
Note: Athletes generally don't burn much protein for fuel during
exercise unless their glycogen (carb) stores are depleted. The bottom
line: Meals/snacks with carbs as the foundation, protein on the side
offer the right balance for endurance performance.
