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Performance, Recovery, and Nutrient Timing
Athletes and those working with them can benefit greatly from understanding how to time meals for performance and recovery. When it comes to performance nutrition, it is useful to think about first maximizing liver and muscle glycogen stores and maintaining appropriate nutrition to fuel exercise. CHO has been shown to take about 4 to 6 hours to be eaten, absorbed, and stored in the liver and muscle as glycogen.7 Recommendations regarding CHO loading for training and events should take this into account for endurance athletes. Morning training sessions or events will benefit from nighttime loading strategies, while afternoon events and training sessions will benefit from morning loading strategies.
To improve performance of high-intensity activity, a CHO (40–60 g) and PRO (5–15 g) snack approximately 45 min before activity may give an advantage.34,35 This snack also serves to spare muscle tissue by decreasing the need for the body to cannibalize it.28
While exercise sessions of less than an hour usually do not require any special nutritional or hydration strategies, sessions lasting longer do. Strategies that manage pre‑, post-, and intraworkout strategies can dramatically aid performance and recovery. This is when electrolyte solutions and sports drinks consumed before and during exercise have an important role. These beverages can help prevent low blood sugar, optimize hydration, replace loss of minerals, and reduce the immune suppression that occurs after intense long-duration exercise.36-41 A CHO beverage of 6% to 8% with an equal mixture of glucose and fructose taken every 20 min during exercise can be helpful.
Postexercise, there is a unique opportunity to fuel the body for recovery. Nutritional strategies should be instituted within the first 30 to 60 min after the cessation of exercise. A mixed CHO/PRO beverage containing close to a 3:1 ratio of CHO to PRO after exercise appears to provide greater recovery benefits than lesser amounts of CHO.6,7,42,43 Upon completion of this postworkout "snack," a more CHO-heavy postworkout meal should be eaten within 90 min. The addition of a small amount of fat may also be helpful in stabilizing blood glucose levels.
Most athletes will taper their training by 1/3 to 1/2 on days 2 to 5 leading up to their event. During this time, it may be beneficial to consume from 200 to 300 extra g of CHO daily. This technique has been shown to maximize glycogen storage pre-event and improve performance.6,7,42,43
The following points are the ISSN position stand on nutrient timing1:
- Prolonged exercise (>60–90 min) of moderate- to high-intensity exercise will deplete the internal stores of energy, and prudent timing of nutrient delivery can help offset these changes.
- During intense exercise, regular consumption (10–15 fl oz.) of a carbohydrate/electrolyte solution delivering 6% to 8% CHO (6–8 g CHO/100 ml fluid) should be consumed every 15 to 20 min to sustain blood glucose levels.
- Glucose, fructose, sucrose, and other high-glycemic CHO sources are easily digested, but fructose consumption should be minimized as it is absorbed at a slower rate and increases the likelihood of GI problems.
- The addition of PRO (0.15–0.25 g PRO/kg/day) to CHO, especially postexercise, is well tolerated and may promote greater restoration of muscle glycogen when carbohydrate intakes are suboptimal.
- Ingestion of 10 to 20 g of essential amino acids and 30 to 40 g of high-glycemic CHO within 3 hrs after an exercise bout and immediately before exercise has been shown to significantly stimulate muscle PRO synthesis.
- Daily postexercise ingestion of a CHO + PRO supplement promotes greater increases in strength and improvements in lean tissue and body fat percentage during regular resistance training.
- Milk PRO sources (e.g., whey and casein) exhibit different kinetic digestion patterns and may subsequently differ in their support of training adaptations.
- Dietary focus should center on adequate availability and delivery of CHO and PRO. Including small amounts of fat does not appear to be harmful, and may help to control glycemic responses during exercise.
- Irrespective of timing, regular ingestion of snacks or meals providing both CHO and PRO (3:1 CHO: PRO ratio) helps to promote recovery and replenishment of muscle glycogen when lesser amounts of CHO are consumed.
The foundation of health for the average person is similar to the foundation for improving athletic performance in the athlete. If there is a deficiency in sleep, nutrition, or hydration, athletic performance will suffer. It is extremely important to address these issues before looking for the magic ergogenic pill, because lifestyle deficiencies will negate the potential other ergogenic aids. As stated above, sufficient sleep, caloric intake, and hydration can be ergogenic by themselves. The primary aids for enhancing athletic performance are as follows: sleep and caloric sufficiency, adequate hydration, adequate recovery, and appropriate timing of nutrients.
Hydration and Athletic Performance
Performance can be significantly impaired when >2% body weight is lost through sweat. When a 70 kg athlete loses >1.4 kg of body weight during exercise (2%), performance is often significantly decreased.
Further, weight loss >4% of body weight during exercise may lead to heat-related illness, and possibly death.
The normal sweat rate of athletes ranges from 0.5–2.0 L/h depending on temperature, humidity, exercise intensity, and sweat response to exercise .
To maintain fluid balance and prevent dehydration, athletes need to ingest 0.5–2 L/h of fluid in order to offset weight loss. This requires frequent ingestion of 6–8 oz of cold water or sports drink every 5–15 min. during exercise.
Athletes should not depend on thirst to prompt them to drink because people do not typically get thirsty until they have lost a significant amount of fluid through sweat.
Athletes should consider weighing themselves prior to and following exercise training to ensure that they maintain proper hydration. They should consume 3 cups of water for every lb. lost during exercise to adequately rehydrate themselves. Athletes should train themselves to tolerate drinking greater amounts of water during training and make sure that they consume more fluid in hotter/more humid environments.
Preventing dehydration during exercise is one of the most effective ways to maintain exercise capacity.
Inappropriate and excessive weight loss techniques (e.g., cutting weight in saunas, wearing rubber suits, severe dieting, vomiting, using diuretics) are extremely dangerous and should be prohibited. Making weight through dehydration techniques also causes one to compromise performance.
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Keoni Teta, ND, LAc, is a naturopathic physician and acupuncturist practicing at the Naturopathic Health Clinic of North Carolina in Winston-Salem with his wife, Jillian, and brother, Jade, an integrative physician specializing in natural health, fitness, and body transformation. After graduating from Bastyr University, they cofounded Metabolic Effect, an international health and wellness company that focuses on balancing hormones for fat loss using rest-based exercise, sports nutrition, and lifestyle medicine. They are coauthors of The Metabolic Effect Diet and contributing authors to The Textbook of Natural Medicine, 4th ed.
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