The Importance of the Recovery Process in Repetitive Exercise Training
The cool-down process is important in exercise because it allows the processes of the body to gradually recover to resting levels. Even after consecutive days of physical activity, one may sometimes feel run down and out of energy if he/she does not incorporate a proper cool-down into the exercise routine. Depending on the activity, the cool-down may include any combination of tapering the intensity at the completion of an aerobic workout, a slow jog or brisk walk, or stretching. These recovery processes are essential for the heart, blood, and muscles. There are certain circumstances when recovery becomes even more crucial for continued performance, such as multi-training sessions per day, tournament play, prelims/finals in a single day (such as a swim or track meet where the morning session performance determines if one competes for the finals), and day-long events with time between performances. This article serves to highlight information on nutrition, rest, and muscular training that will aid anyone from the casual to serious athlete in post-exercise recovery.
Nutrition for optimal recovery
Despite the large volume of literature on the new fad diets like Adkins or South Beach claiming that reducing carbohydrate intake will help with weight loss, carbohydrates remain the most recommended nutrient before and after exercise for muscle fuel and recovery. Ingesting protein and carbohydrates post-exercise has been shown to improve the net balance of blood protein levels following resistance exercise1. Energy from dietary fat is also consumed during the exercise process. However, depending on the type of workout, fat is used to more (aerobic) or less (anaerobic) of an extent and are thus not as important in the recovery processes as carbohydrates.
Moderate to intense aerobic exercise can greatly increase the need for water intake. Quantity of water intake varies between patients and is especially important in hot climate environments where individuals can lose more than 2% of total body weight, impeding performance2. Drinks with carbohydrates, such as sports drinks or real fruit juices, are a simple way to improve recovery over simply re-fueling with water. Carbohydrates replenish the simple sugars that are first broken down by cellular metabolism to be used as muscle fuel. Athletes who replenish with carbohydrates directly post-endurance events have shown improved endurance capacity during prolonged intermittent exercise3. A carbohydrate-electrolyte drink enhances exercise capacity by elevating blood glucose levels, preventing hypoglycemia and fatigue4. Carbohydrate-electrolyte consumption would be a critical factor for athletes competing in a single day prelims-finals format or for morning-afternoon workout recovery.
Some websites and popular fads may suggest that alcohol plays a positive roll in the recovery process. For example, the Netherlands Organization for applied Scientific Research demonstrated that beer boosts blood concentration of vitamin B6, which is important for processing protein and preventing homocystines from blocking blood vessels5. However, since alcohol acts primarily on the body as a diuretic and contains no vitamins or minerals (empty calories), it probably has very little overall value in the exercise recovery process.
Competing at a high level in a multiple session situation or in a prelims-finals setting requires adequate rest to maximize repeat potential. One study investigated the effect of increasing the rest period between bouts of intense physical activity6. Subjects demonstrated increased running velocity and work output when they actively recovered for a longer period of time to an asymptotic level of ~120 s.
Full recovery of muscle function not only entails adequate rest, but also must include an active recovery period. Light exercise has been shown to help the recovery process of muscles as compared to taking the day off from training completely. When muscles are tired, 2-3 days of light training helps serum hormone levels return to normal pre-exercise levels as compared to the elevated states achieved post-exercise7. Therefore, not only does active recovery help build endurance, but it also returns the muscles to normal activity levels more quickly.
Sleep is an essential piece of the recovery puzzle that is overlooked during sporting events in which the athlete is tapered or resting for a championship competition. When energy levels are high, it might seem easier to sleep less and still feel fine. Actually, sleep deprivation has severe inverse effects on high-level performance when compared to an initial assessment, such as a tournament play situation5.
During heavy exercise, oxygen cannot be delivered to the muscle tissues quickly enough to meet the needs of the exerting muscle. This process drives metabolic acidosis and increased respiratory rate. Therefore, decreasing the level of lactic acid in muscles is another important aspect of exercise recovery. Build up of lactic acid causes muscles to ache and feel sore up to several days after an intense workout. An active recovery process for anaerobic or sprint training has been show to reduce blood lactate levels immediately after the recovery as well as 5 minutes post-recovery8. However, the same study also concluded that short, repetitive sprinting performance was better during a passive recovery process as opposed to active recovery.
This is merely a glimpse into the importance of recovery post-exercise and why it is crucial to allow ample time in a daily workout routine for the muscular recovery. It is important to be mindful of a proper dietary intake and incorporate plenty of carbohydrates into the diet, especially directly after exercise, which will help the processes of the body return to normal functioning levels. Proper rest becomes important for competitions and situations where the athlete needs maximum recovery in a minimal period of time. Active recovery versus stationary rest improves performance post-initial workout or competition. The active recovery process also assists muscles in eliminating lactic acid build up. Look for a follow-up article that will discuss the issues of massage, stretching, and dietary antioxidants in the recovery process.
1. Holm L, Esmarck B, Suetta C, Matsumoto K, Doi T, Mizuno M, Miller BF, Kjaer M. Postexercise nutrient intake enhances leg protein balance in early postmenopausal women. J Gerontol A Biol Sci Med Sci. 2005 Sep;60(9):1212-8.
2. Shirreffs SM. The importance of good hydration for work and exercise performance. Nutr Rev. 2005 Jun; 63(6 Pt 2):S14-21.
3. Nicholas CW, Williams C, Lakomy HK, Phillips G, Nowitz A. Influence of ingesting a carbohydrate-electrolyte solution on endurance capacity during intermittent, high-intensity shuttle running. J Sports Sci. 1995 Aug;13(4):283-90.
4. Byrne C, Lim CL, Chew SA, Ming ET. Water versus carbohydrate-electrolyte fluid replacement during loaded marching under heat stress. Mil Med. 2005 Aug; 170(8):715-21.
5. Racinais S, Hue O, Blonc S, Le Gallais D. Effect of sleep deprivation on shuttle run score in middle-aged amateur athletes. Influence of initial score. J Sports Med Phys Fitness. 2004 Sep;44(3):246-8.
6. Seiler S, Hetlelid KJ. The Impact of Rest Duration on Work Intensity and RPE during Interval Training. Med Sci Sports Exerc. 2005 Sep;37(9):1601-1607.
7. Vuorimaa T, Vasankari T, Mattila K, Heinonen O, Hakkinen K, Rusko H. Serum hormone and myocellular protein recovery after intermittent runs at the velocity associated with VO(2max). Eur J Appl Physiol Occup Physiol. 1999 Nov-Dec;80(6):575-81.
8. Toubekis AG, Douda HT, Tokmakidis SP. Influence of different rest intervals during active or passive recovery on repeated sprint swimming performance. Eur J Appl Physiol. 2005 Mar;93(5-6):694-700. Epub 2004 Nov 20.
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