What’s in Your Bottle

NUTRITION_WhatsInYourBottle

By Stacey Penney, NASM-CPT, CES, PES, FNS

Walking through the grocery store beverage aisle, or aisles as the choices continue to grow, do you know what is in your bottle? There are drinks for before, during, and after your workout. There are others to improve your immunity, your mental concentration, your sleep, or even a healthy glow. Here’s a run down on some of the more common additions to your drink and a bit about the marketed benefits of what they can or can’t do.

Deciphering the Label

Antioxidants: Antioxidants have made their way into our bottles to combat the free radicals that come from the oxidative stress of exercise. Antioxidants are already in the foods we regularly eat, foods rich in vitamins A, C, and E including berries, whole grains, some vegetables and even chocolate (1). As supplements these gems are touted as being able to prevent muscle tissue damage, improve recovery, and boost aerobic endurance, but some researchers question these claims due to insufficient data (2). (For more on antioxidants)

Caffeine: One of the few proven ergogenic aids, this stimulant can increase performance during aerobic endurance activities and high-intensity short-duration events (2). On the negative side, caffeine can cause insomnia, the jitters, rapid heart rate, and increased urine output.

Coconut Water: Taken from the center of green coconuts (versus the milk from mature coconuts), this clear liquid is high in potassium. Containing about 1.3 grams of sugar and 5.45 mg sodium per ounce, you may need to include a salty carbohydrate snack to keep you going if you are exercising for an extended period of time (3).

Electrolytes: Theses minerals included sodium, potassium, chloride, magnesium and calcium. They keep the electrical charges firing in your body, especially for things like muscle contractions and pumping the heart (4-5). When you’re exercising and you don’t have enough electrolytes circulating, you may experience muscle cramps or muscle weakness. A more severe and potentially deadly result of not replacing sodium lost to sweating is exercise-induced hyponatremia. This is seen more often in marathon runners who drink large quantities of water causing the body’s sodium concentration to become overly diluted (4-5).

Ginseng: Though no proven effect on performance as an ergogenic aid, it may potentially boost immunity, lower blood sugar, and modestly improve learning and concentration (6).

Green Tea: High in catechins, a heart disease fighting antioxidant, green tea is linked to a host of health and performance benefits. Included in this list is protection against exercise-induced oxidative damage, fat loss, improved endurance, and even potentially masking testosterone doping (not a benefit we promote) (7-10). And don’t forget, green tea is also a source of caffeine.

L-theanine: Want to improve your mood and reduce your stress? Try a dash of L-theanine. An amino acid found in green tea, it’s been used to treat anxiety, high blood pressure, and even Alzheimer’s disease prevention (11).

Niacin: Only needing a daily dose of 16 mg of this B vitamin for men and 14 mg for women, niacin is important for both the aerobic and anaerobic energy pathways (4,12). Many of our foods are fortified with niacin, and it is also available in meats, poultry, fish, whole-grain breads and grain products (4). The body can also make niacin from the amino acid tryptophan (4). Taking in too much niacin can cause flushing, tingling, and itching (4).

Protein: Functioning to build and repair body structures, protein synthesis increases dramatically after exercise. Consuming protein 30-45 minutes after exercise can increase synthesis levels to 150% over resting levels. Consuming a carbohydrate-protein beverage within the anabolic window (first 1 to 2 hours post-exercise) is also beneficial for enhancing muscle glycogen recovery (13).

Still confused about all the choices? Not to worry, water is still one of the best overall choices for rehydrating. If engaging in moderate-to-high intensity activity for more than 60 minutes, select sport drinks (containing 6-8% carbohydrate) to help replace the carbohydrates and electrolytes lost (14).

References

  1. Helwig, B. Antioxidants and Exercise. ExRx.net. Accessed Aug 19, 2013 http://www.exrx.net/Nutrition/Antioxidants/Antioxidants.html.
  2. Williams, M. (1998) Nutritional Ergogenics & Sports Performance President’s Council on Physical Fitness & Sports Research Digest, 3(2).
  3. NASM’s The Training Edge Magazine. Coconut water: cracking the case. Winter 2013.
  4. Insel P., Ross D., McMahon K., et al. Nutrition. 4th ed. Sudbury, MA: Jones and Bartlett; 2011.
  5. Powers S., Howley E. Exercise Physiology: Theory and Application to Fitness and Performance. 8th ed. New York, NY:McGraw Hill, 2012.
  6. Ginseng for Your Immune System, Concentration, Heart, and Menopause. WebMD. Ed. M. Ratini. WebMD, Accessed 19 Aug. 2013. http://www.webmd.com/vitamins-and-supplements/lifestyle-guide-11/supplement-guide-ginseng.
  7. Iowko, E, Sacharuk, J., Balasinska, B. et.al. Green tea extract supplementation gives protection against exercise-induced oxidative damage in healthy men. Nutrition Research. 2011 Nov 31(11):813-21.
  8. Venables, M. Hulston, C. Cox, H. et.al. Green tea extract ingestion, fat oxidation, and glucose tolerance in healthy humans. American Journal of Clinical Nutrition. 2008, March 87(3);778-784.
  9. American Physiology Society. Green tea extract boosts exercise endurance 8-24%, utilizing fat as energy source. ScienceDaily, 31 Jan. 2005. Web. 20 Aug. 2013.
  10. Jenkins, C. Petroczj, A., Barker, J. et.al. Dietary green and white teas suppress UDP-glucuronosyltransferase UGT2B17 mediated testosterone glucuronidation. Steroids, 2012 May 77(6); 691–695.
  11. Kimura, K. Ozeki, M., Juneja, L. ,Ohira, H. Theanine reduces psychological and physiological stress responses. Biological Psychology. 2007 Jan;74(1):39-45.
  12. Clark, M. NASM Essentials of Personal Fitness Training 4th ed. Baltimore, MD: Lippincott Williams & Wilkins; 2012.
  13. Ivy, J., Goforth, H., Damon, B., et.al. Early postexercise muscle glycogen recovery is enhanced with a carbohydrate-protein supplement. Journal of Applied Physiology 2002 October 93(4);1337-1344.
  14. American Dietetic Association, Dietitians of Canada, and the American College of Sports Medicine Position Paper (Nutrition and Athletic Performance). Journal American Dietetic Association. 2000;100:1543-1556.

Stacey Penney, Contributing Content Strategist with the National Academy of Sports Medicine (NASM), holds a degree in Athletic Training from San Diego State University, along with credentials in Health Promotion Management and Consulting (UCSD), and Instructional Technology (SDSU). She holds certifications from NASM and ACE in personal training, corrective exercise, sports performance, group exercise, and health coaching. Previous San Diego Fall Prevention Task Force Chair, she develops continuing education curriculum for many fitness organizations in addition to personal training, writing, coaching youth soccer, and pursuing an MS in Exercise Science.