Wednesday, June 27, 2012

Caffeine and Athletic Performance

Scientists have been studying the effect of caffeine on athletic performance for quite some time. Based on the evidence that exists, the American College of Sports Medicine (ACSM) currently reports that 3 to 9 milligrams of caffeine per kilogram of body weight can improve endurance athletic performance (lasting up to 2 hours) and short-term, intense exercise (lasting about 5 minutes).


Body weight = 150 lbs

150 lbs / 2.2 = 68.2 kgs

68.2kgs X 3 mg caffeine = 204.6

68.2kgs X 9 mg caffeine = 613.8

So a person who weighs 150 pounds would need between 205 mg and 614 mg of caffeine. A cup of coffee has at least 100 mg of caffeine.

Studies have shown that caffeine can help to increase power output and speed. Unfortunately, studies cannot confirm that caffeine in the form of coffee will elicit the same results because caffeine was administered in pill form. Fortunately, caffeine does not cause dehydration as commonly thought.

Practical advice: If you are using gels or sports drinks with caffeine in them, know that they are safe and they may even improve your performance. Do not ever try something new on race day! Do not overdo the caffeine. By that, I mean that more is not always better. Be sensible, do not take so much caffeine that you are jittery, and don't expect this to help you win the race. Train, train, train!

Tuesday, June 19, 2012

A Hidden Danger For Runners...

You're outdoors on a nice day getting exercise. What could be bad about that? While you're doing your body "good" by running, you may be ruining the appearance of your skin and putting yourself in danger for skin cancer. Of course, anyone who participates in outdoor sports is at risk for this.

This summer, and ALWAYS, make a commitment to wear sunscreen when you run outdoors. Remember that ultraviolet rays are still busy damaging your skin even on cloudy days. In fact, I got the worst burn of my life on a very overcast day when I was a kid. I will never do that again! However, I know that I still make silly decisions. Last October I went out for a run and came back with a burn. Even if I hadn't gotten a burn, I know there still would have been damage to my skin after being outside in a tank top and shorts for an hour and a half. If you're having trouble making yourself take the time to apply sunscreen, ask yourself, "Do I really want to have ugly sun-damage spots on my skin and look ten years older than I really am?" Even if you escape skin cancer, the sun will likely derail your plans for graceful aging.

Choose a broad spectrum sunscreen and reapply every two hours, even if the sunscreen claims to be sweat resistant. Check out this article for information about new FDA guidelines for sunscreens. Be sure to use an ounce of sunscreen to achieve the full benefits of skin protection.

In addition to sunscreen, don't forget other protective measures. Invest in some running sunglasses, such as my favorite, Tifosi. A hat or visor are also really good ideas to keep the sun off of your face. Hats are best if you have any exposed scalp.

We are so fortunate that we live in a time when sunscreen is available. Let's take advantage of this great invention and protect our skin.

Sunday, June 10, 2012

Glutamine for Endurance Athletes

Glutamine is an amino acid that has gained popularity among endurance athletes as an important post-workout nutrient. (Amino acids are the building blocks of protein). Many athletes take supplements or consume sports drinks that contain glutamine in order to improve immune function.

Glutamine is an important fuel for immune cells and is typically decreased in the body after endurance exercise. Immune function is known to be lowered after endurance exercise as well, so the idea that supplementing with glutamine post-workout would improve immune function does make sense. However, evidence shows that even when glutamine supplementation is used, immune function still suffers after endurance exercise. In fact, studies have not been able prove that a low level of glutamine in the body causes a higher rate of infections. So, even though there is a reduction in glutamine, and it is used by immune cells for energy, it doesn't appear to be the magic bullet for avoiding infections in the over-trained athletes.

It is interesting to note that immune function does improve in moderately trained individuals, but suffers in sedentary people. Moderation wins again, my friends. (Regardless, I can't tear myself away from marathon training!) Another important point is that glutamine is a non-essential amino acid. That means that your body can manufacture the nutrient all by itself. However, you should definitely increase your calories after a long work-out and include protein. Glutamine is a highly abundant amino acid in many foods including red meat, fish, poultry, legumes, and vegetables. There is no need to buy an expensive supplement or drink that contains this amino acid because we have found that it doesn't show efficacy in improving immune function and you can get it from your regular diet.

Agostini, F. & Biolo, G. Effect of physical activity on glutamine metabolism. Curr Opin Clin Nutr Metab Care. 2010 Jan;13(1):58-64.

Calder PC, Yaqoob P. Glutamine and the immune system. Amino Acids. 1999;17(3):227-41.

Gleeson, M. Dosing and efficacy of glutamine supplementation in human exercise and sport training. J. Nutr. Oct 2008; 138(10):2045S-2049S.

Parry-Billings M, Budgett R, Koutedakis Y, Blomstrand E, Brooks S, Williams C, Calder PC, Pilling S, Baigrie R, Newsholme EA. Plasma amino acid concentrations in the overtraining syndrome: possible side effects on the immune system. Med Sci Sports Exerc. 1992 Dec;24(12):1353-8.

Walsh NP, Blannin AK, Robson PJ, & Gleeson M. Glutamine, exercise, and immune fuction. Links and possible mechanisms. Sports Med. 1998 Sep;26(3):177-91.

Tuesday, June 5, 2012

Fiber Update

Someone recently requested information on the importance of fiber. I did briefly address this in a previous blog; however, I'll do a little update on that today.

Currently, the recommendations are 38 grams of fiber for most adult males and 25 grams of fiber for most adult females. Check this out for a more detailed breakdown. I have found with clients, it is quite difficult for men to reach that lofty goal of 38 grams daily. I recommend that you just try, try, and try some more! Even if you don't reach 38 grams, you will most likely do much better than the average American.

Be sure to obtain most of your fiber from natural sources, such as whole grains, fruits, vegetables, legumes, nuts, and oats. Research has shown than many of the products on the market that contain man-made fibers do nothing but give people gas. Unfortunately it is difficult to be sure which foods contain natural fibers and which ones contain man-made fibers. That is why I encourage you to choose mostly unprocessed foods that are naturally high in fiber.

Here are benefits of a high fiber diet:

1. Possible decrease in colon cancer risk. There are mixed results in studies that examine this.
2. Better weight control or weight loss. Fiber increases the feeling of fullness possibly decreasing total caloric intake. Also, foods that are high in fiber, such as fruits and vegetables, have less calories and more "bulk".
3. Fiber reduces constipation.
4. Improves blood cholesterol levels.
5. Helps regulate blood sugar in diabetics.

Read this for more information!