The Fit Life in Words
Tips on Nutrition, Workouts, and more. Because you can always improve.
What would happen if you put regular unleaded gas in a Porsche? The same thing that would happen to an athlete who didn't properly fuel their body. They wouldn't perform very well. The more intense the sport or exercise, the greater the body's need for nutrients. It's a simple game of input and output. Athletes who participate in endurance sports (more than 1 hour of consistent activity) have specific needs because of the demands they put on their bodies. Endurance athletes lose more electrolytes through perspiration, wear and tear requires increased intake of antioxidants, and muscle-breakdown necessitates the intake of amino acids.
The recommended dietary intake ranges from 1,000 to 1,500 mg/day depending on age and gender. Athletes should make sure they get the upper end of that. Training for more than 7 hours per week may cause hormonal declines in females, compromising bone formation. Recent research shows that male endurance athletes of all ages experience declines in testosterone levels which can cause osteoporosis.
Monitor your calcium intake. Dairy foods can supply required amounts. For example, a cup of skim milk contains about 300mg of calcium. If sensitivities exclude them from the diet, then supplements are necessary.
For athletes who train for 6 or more hours a week, iron deficiency is a concern. Athletes use iron stores more quickly than nonathletes. The recommended daily intake for iron ranges from 10 to 15 mg/day; an amount easily acquired from food. But due to greater demands on an athlete's body, iron-deficiency anemia is commonly reported. Female athletes who are unable to correct anemia through diet can benefit from supplements.
This is a big one! Magnesium is involved in adenosine triphosphate (ATP) production from fatty acid oxidation, post-contractile muscular relaxation, and bone remineralization. If that wasn't enough, it's also involved in phosphatidylglycerol (DPG) production, which is important to red blood cell formation. ATP, which is in all cells but particularly muscle cells, store energy. Low magnesium levels can contribute to early fatigue, nausea, and muscle cramps.
Athletes lose magnesium through sweat and urine. This, combined with the fact that athletes' diets are usually low in magnesium, generally leads to the need for supplementation. Recommended intake for endurance athletes is 500 to 800 mg daily. Higher doses can cause diarrhea.
It's responsible for regulating total body water and stabilizing controlled and automatic muscle contractions. It is also lost through sweat and urine.
In a study of athletes running 40 minutes at 70 degrees Fahrenheit, potassium loss was estimated at 435 mg/hour. The rate of potassium loss is about 200 mg/kg of weight lost during exercise.
Cells release potassium into the bloodstream and serum levels rise with exercise, possibly causing fatigue. Potassium supplementation after short events (less than 2 hours), and during and after long events, is a must. Post workout, athletes should take about 435 mg/hour of exercise. Be cautious though because too much too quickly can cause cardiac arrest.
It's a free radical-scavenging tripeptide made up of glutamine, cysteine, and glycine. It is essential to antioxidant glutathion peroxidase (SeGPx) and is concentrated in the lining of the GI tract and lungs, in the liver, and in skeletal muscle.
Research shows selenium benefits athletes' immune function and helps repair cellular damage. Selenium supplementation effects on muscle SeGPx was studied in 24 healthy nonsmoking males. Half took 240 mcg of sodium selenite and the other half took a placebo. After cycling to exhaustion, the group that too the selenium showed less cellular damage.
Supplementation with 200 mcg of selenium is safe and highly recommended for endurance athletes.
We all know this one. How could you not when there are checkpoint stands set up at races labeled "We have salt"? Sodium helps cells retain water and prevents dehydration. It also enables ATP generation. In events lasting longer than 5 hours, hyponatremia (dangerously low sodium) is a real concern.
A study was performed on 36 athletes doing a triathlon (3-4 hours) and 64 athletes at an ironman race (9-15 hours). No athletes were hyponatremic after the shorter race but 27% were hyponatremic after the ironman. An average of 175 of the ironman participants required medical attention.
Athletes should aim for 80 to 100 mg sodium per quart of hydrating beverage and 100 to 300 mg sodium per hour from other sources.
Zinc aids in post-exertion tissue repair and in the conversion of food to fuel. Athletes have lower serum zinc levels compared with nonathletes. Studies correlate endurance with compromised immunity as a result of zinc depletion.
Those who train without days off lose zinc even quicker! In a study of cyclists, researchers looked at zinc excretion via sweat. Half of the group underwent intense training for 2 months. The other half underwent moderate training with 2-3 days off per week. The 1st group showed increased zinc excretion while the 2nd group showed no increase. The study led researchers to believe decreases in zinc levels leads to an increase in stress and fatigue.
Athletes should take 30 to 60 mg of zinc daily.
8. Vitamin E
In a study of 30 top-class cyclists, 5 months of natural vitamin E (alpha-tocopherol) supplementation at an 800-IU daily dose significantly decreased oxidative damage to muscle tissue!
The amount of vitamin E necessary to benefit athletes is not obtainable through diet. The jury is still out on natural vs. synthetic vitamin E, but endurance athletes should take 400 to 800 IU/day.
The government's recommended daily intake is 0.8g per kg/body weight, but that's based on the needs of nonathletes. Recent studies indicate that protein needs increase during strenuous activity.
Endurance athletes need more protein for different reasons than strength athletes do. Endurance athletes primarily use protein for maintaining aerobic metabolism, compared with the increased tissue-repair needs of strength athletes. When protein intake is too low, the body gets what it needs from lean tissue, which gives overtrained endurance athletes a terrible experience. A protein deficit also impairs recovery and the ability to heal injuries.
Researchers recommend endurance athletes intake 1.2 to 1.4g per kg/body weight of protein daily.
This amino acid increases the numbers of lymphocytes and macrophages (part of your immune system). Prolonged exercise consistently lowers glutamine levels. Supplementation reduces vulnerability to infections, which typically come in the days or weeks following marathons and triathlons.
In one study, 200 runners and rowers were given placebo or 2,000 mg glutamine 2 hours after exercise. In the 7 days following exercise, 81% of the glutamine-supplemented group were infection-free compared to 49% in the placebo group. That is a massive difference!
A supplement that provides 2 g glutamine daily is a wise choice for athletes in training.