The Psychological Benefits of Exercise

brainhealthFew can argue the many benefits of exercise—it makes people stronger, healthier, and adds years to their lives. There are also a number of less tangible effects of exercise in addition to well-defined muscles and slimmer waistlines. From a psychological perspective, exercise is one of the most important things a person can do to promote mental well-being and overall happiness. Many people are familiar with the mood-boosting effects of exercising regularly, but what is actually happening inside your brain in the midst of a good workout?

Read the basic psychological benefits of exercise or learn the more technical details.

Articles by Alycia Parnell.

Timing of Eating and Exercise

Athlete-Nutrition-1The role of nutrition in regard to physical activity and athletic performance is of high importance for all athletes. There are many aspects to consider in the realm of sports nutrition, and an important area is the timing of food and fluid consumption around exercise. The research in this area points to several specific guidelines to assist athletes in optimizing their performance by not only consuming the proper nutrients, but also consuming them in the appropriate time frame around exercise.

Read the basic information about timing your eating or learn the more technical details of nutrition intake around exercise.

Articles by Jamie Saunders

The Psychological Benefits of Exercise (Basic)

happy-woman-after-runFew can argue the benefits of exercise—it makes us stronger, healthier, and adds years to our lives. In addition to promoting well-defined muscles and slimmer waistlines, exercise is also one of the most important things a person can do to promote psychological well-being and overall happiness.

Many discussions involving the brain-boosting effects of exercise involve the word ‘endorphins.’ These are a group of chemicals in the brain that act as natural painkillers and resemble opiate drugs such as morphine (Levinthal 2008), which is no coincidence—heightened moods during and after exercise are very similar to the sensations outlined by people describing drug or trance states (Dietrich and McDaniel 2004). In times of stress or pain, such as a strenuous workout, endorphins block the transmission of pain impulses to the brain and create an elevated mood (McGovern 2005). Researchers in a 2008 study of ‘runner’s high,’ or the euphoric state often described by endurance athletes, scanned runners’ brains before and after long runs, revealing that sustained exercise promoted the release of endorphins in brain regions where emotional processing occurs (Boecker et al. 2008).

In addition to the short-term positive effects of a workout such as runner’s high, exercise has powerful long term effects in terms of depression and overall mental health. Several large-scale studies  have shown that people who exercise moderate amounts every week were less anxious, depressed, and neurotic, and had higher levels of general well-being than more sedentary participants (Hassmén et al. 2000, De Moor et al. 2006). Exercise does even more than elevate mood and alleviate depression; it can actually promote changes in the brain through neurogenesis, or the creation of new brain cells. These brain cells, called neurons, appear in the hippocampus, the brain structure in charge of learning and memory (McGovern 2005). Laboratory studies have shown more complex networks of neurons among subjects who exercise regularly than those who don’t (Comery et al. 1996). One possible reason for this could be a protein that promotes growth in the hippocampus after mild stresses associated with exercise (Mattson et al. 2004). Additional animal studies have also shown that this protein could be partially responsible for the positive effect of exercise on depression (Zheng et al. 2006).

Exercise can combat the symptoms of an aging brain. Beginning at age 30, the human brain begins to lose nerve tissue. Since exercise creates more complex networks in the brain, it could serve a preventive role for brain disorders that progress through loss of neurons, such as Alzheimer’s disease (McGovern 2005). Regular physical activity can reduce the risk of dementia by 28% and Alzheimer’s by 45% (Hamer and Chida 2009), and also reduce cognitive decline in the older population at large. Older adults who exercise regularly experience significant improvements in tasks such as planning, inhibition, and working memory (Kramer et al. 1999). A study of patients already diagnosed with Alzheimer’s disease found that those involved in a care plan including 60 minutes of exercise per week showed lower rates of institutionalization after two years (Teri et al. 2003).

Researchers have sought the perfect dose of exercise for maximum benefits. People reap rewards from any amount, but more seems to be better (Trivedi et al. 2011), and high- and low-intensity are equally effective (King et al. 1993). Clinicians generally recommend moderate-intensity exercise for at least 150 minutes per week (Trivedi et al. 2011). Exercise is a powerful tool in maintaining a healthy lifestyle for both the mind and the body.

By Alycia Parnell

Read the technical details about the psychological benefits of exercise.

Literature Cited 

  1. Boecker, H., T. Sprenger, M.E. Spilker, G. Henriksen, M. Koppenhoefer, K.J. Wagner, M. Valet, A. Berthele, and T.R. Tolle. 2008. The runner’s high: opioidergic mechanisms in the human brain. Cerebral Cortex, 18: 2523-2531.
  2. Comery T.A., C.X. Stamoudis, S.A. Irwin, and W.T. Greenough. 1996. Increased density of multiple-head dendritic spines on medium-sized spiny neurons of the striatum in rats reared in a complex environment. Neurobiology of Learning and Memory 66: 93–96.
  3. Dearman, J., and K.T. Francis. 1983. Plasma levels of catecholamines, cortisol, and beta-endorphins in male athletes after running 26.2, 6, and 2 miles. The Journal of Sports Medicine and Physical Fitness  23: 30-38.
  4. De Moor, M.H, A.L. Beem, J.H. Stubbe, D.I. Boomsma, and E.J. De Geus. 2006. Regular exercise, anxiety, depression and personality: a population-based study. Preventive medicine 42: 273-279.
  5. Dietrich, A., and W.F. McDaniel. 2004. Endocannabinoids and exercise. British Journal of Sports Medicine 38: 536-541.
  6. Hamer, M., and Y. Chida. 2009. Physical activity and risk of neurodegenerative disease: a systematic review of prospective evidence. Psychological Medicine 39: 3.
  7. Hassmén, P., N. Koivula, and A. Uutela. 2000. Physical exercise and psychological well-being: a population study in Finland. Preventive Medicine 30: 17-25.
  8. King, A.C., C.B. Taylor, and W.L. Haskell. 1993. Effects of differing intensities and formats of 12 months of exercise training on psychological outcomes in older adults. Health Psychology 12: 292.
  9. Kramer, A.F., S. Hahn, N.J. Cohen, M.T. Banich, E. McAuley, C.R. Harrison, J. Chason, E. Vakill, L. Bardell, R.A. Boileau, and A. Colcombe. 1999. Ageing, fitness and neurocognitive function. Nature 400: 418-419.
  10. Levinthal, C.F. 2008. Drugs, behavior, and modern society. Pearson, Boston, MA.
  11. Mattson, M.P., W. Duan, R. Wan, and Z. Guo. 2004. Prophylactic activation of neuroprotective stress response pathways by dietary and behavioral manipulations. NeuroRx 1: 111-116.
  12. McGovern, M. K. 2005. The effects of exercise on the brain. Serendip Studio. Bryn Mawr College. <http://198.252.64.61/Support/Studies/The Effects of Exercise on the Brain,,BDNF.pdf>
  13.  Teri, L., L.E. Gibbons, S.M. McCurry, R.G. Logsdon, D.M. Buchner, W.E. Barlow, W.A. Kukull, A.Z. LaCroix, W. McCormick, and E.B. Larson. 2003. Exercise plus behavioral management in patients with Alzheimer disease: a randomized controlled trial. Jama 290: 2015-2022.
  14. Trivedi, M.H., T.L. Greer, T.S. Church, T.J. Carmody, B.D. Grannemann, D.I. Galper, A.L. Dunn, C.P. Earnest, P. Sunderajan, S.S. Henley, and S.N. Blair. 2011. Exercise as an augmentation treatment for nonremitted major depressive disorder: a randomized, parallel dose comparison. Journal of Clinical Psychiatry 72: 677.
  15. Zheng, H., Y. Liu, W. Li, B. Yang, D. Chen, X. Wang, Z. Jiang, H. Wang, Z.Wang, G. Cornelisson, and f. Halberg. 2006. Beneficial effects of exercise and its molecular mechanisms on depression in rats. Behavioural Brain Research 168: 47-55.

The Psychological Benefits of Exercise (Technical)

Few can argue the many benefits of exercise—it makes people stronger, healthier, and adds years to their lives. There are also a number of less tangible effects of exercise in addition to well-defined muscles and slimmer waistlines. From a psychological perspective, exercise is one of the most important things a person can do to promote mental well-being and overall happiness. Many people are familiar with the mood-boosting effects of exercising regularly, but what is actually happening inside your brain in the midst of a good workout?

Exercise and the Brain

brainhealthIt seems that a majority of discussions involving the positive psychological effects of exercise involve the word ‘endorphins.’ Generally speaking, endorphins are a group of chemicals in the brain that act as natural painkillers and bear a strong resemblance to opiates such as morphine and heroin (Levinthal 2008). In fact, the word ‘endorphin’ is derived from the words ‘endogenous’ and ‘morphine,’ referring to the fact that they are produced within the central nervous system and act similarly to morphine (

Leuenberger 2006). In times of stress or pain, such as a strenuous workout, endorphins are released by the pituitary gland and bind to opioid receptors in neurons, thus blocking the transmission of pain impulses to the brain (McGovern 2005). This connection to opiates is not a coincidence. Many people experience a heightened mood during or after exercise, with such varied subjective descriptions as elation, inner harmony, unity with one’s self, and pure happiness. These mood states are very similar to the sensations outlined by people describing drug or trance states (Dietrich and McDaniel 2004).

The role of endorphins in improved mood states during exercise is widely accepted, but research on the matter has been surprisingly conflicting for a topic that is widely perceived as general knowledge (Harber and Sutton 1984). To study the relationship between endorphins and exercise, many earlier studies have used blood plasma levels. Some of these studies have yielded significant increases in blood plasma endorphin levels, while others have not (Leuenberger 2006).  In addition, there is a fundamental issue with this method of research, which is that the pituitary gland produces the endorphins and releases them into the bloodstream, but very few of them are able to reenter the brain through the blood brain barrier, which is the brain’s protective mechanism selecting what materials can enter from the bloodstream (Dearman and Francis 1983). In 2008, Dr. Henning Boecker came up with some conclusive research on the subject while studying ‘runner’s high,’ or the euphoric state often described by endurance athletes. Rather than blood plasma screening, Boecker employed Positron Emission Tomography (PET). During the study, ten athletes were scanned in a rest state and then again after two hours of endurance running. The scans revealed that sustained physical exercise did indeed promote the release of endogenous opioids in frontolimbic brain regions (where emotional processing occurs), and that there is a close correlation to the perceived euphoria of distance runners (Boecker et al. 2008).

In addition to the short-term positive effects of a workout such as runner’s high, exercise has powerful long-term effects in terms of depression and general feelings of well-being. A large-scale Finnish study had 3,403 participants answer questionnaires about their fitness habits and psychological states. The findings revealed that participants who exercised two to three times per week experienced less depression, anger, cynical distrust, and stress than those who exercised less or not at all. The psychological inventories used indicate enhanced levels of general psychological well-being among the participants (Hassmén et al. 2000). Another large population-based study of 19,288 people found that individuals who exercised at least 60 minutes per week were less anxious, depressed, and neurotic than more sedentary participants (De Moor et al. 2006).

The psychological implications of exercise are even more expansive benefits than elevating mood and alleviating depression. In addition to creating happier people, it can actually promote physiological changes in the brain through neurogenesis, or the creation of new neurons. These neurons appear in the hippocampus, which is the structure in the brain that is responsible for learning and memory (McGovern 2005). Laboratory studies on animal subjects have shown increased complexity of dendrites in the cerebral cortex, which are the parts of neurons that receive signals and thus allow for more complex brain function (Comery et al. 1996). The mechanisms involved in exercise-induced neurogenesis are still being investigated, but recent research has revealed that a protein called brain-derived neurotrophic factor, or BDNF, plays a pivotal role. The mild stresses associated with exercise promote the influx of calcium, which activates transcription factors that tell the BDNF gene to promote neuron growth in the hippocampus (Mattson et al. 2004). Additional animal studies focusing on BDNF in the context of depression have indicated that exercise-induced BDNF production could be partially responsible for the positive effect of exercise on depression symptoms (Zheng et al. 2006). Thanks to BDNF, regular exercise not only promotes happiness, it can also make your brain work better when it comes to learning and memory.

Exercise and Mental Ageing

This role of exercise in learning and memory is significant in the context of cognitive decline and neurodegenerative disorders. Beginning at age 30, the human brain begins to lose nerve tissue. Since aerobic exercise creates a denser network of dendrites between neurons, it could help serve a preventive role for diseases such as Alzheimer’s that progress through loss of neurons (McGovern 2005). One meta-analysis of studies examining the connection between exercise and cognitive decline revealed that regular physical activity reduced the risk of dementia by 28% and Alzheimer’s disease by 45% (Hamer and Chida 2009). In addition to its role in neurodegenerative disorders, exercise has been shown to reduce cognitive decline in the older population at large. One study examined a group of 124 older adults between the ages of 60 and 75 years old in relation to executive control processes such as planning, inhibition, and working memory. The subjects were assigned to either aerobic or anaerobic exercise, such as walking and stretching, respectively. The study revealed significant improvements in tasks requiring executive control among the people who engaged in aerobic exercise (Kramer et al. 1999).

How Much Exercise is Best?

happy-woman-after-runThe results of the previously described studies raise the question, what kind of exercise yields the greatest psychological benefits, and in what doses? A 2011 study of patients suffering from major depressive disorder examined the efficacy of different doses of exercise in relieving their symptoms. One group of subjects was assigned to burn four calories per kilogram of body weight per week, while the second group burned 16 calories per kilogram per week. The study revealed that both groups of patients experienced relief of their depressive symptoms, but the group that exercised more experienced greater benefits (Trivedi et al. 2011). In the context of neurodegenerative disorders, a study of patients already diagnosed with Alzheimer’s disease found that those who were involved in a care plan including at least 60 minutes of exercise per week showed lower rates of institutionalization due to behavioral disturbance after two years (Teri et al. 2003).

Regarding intensity of exercise required to attain psychological benefits, one study showed that all subjects experienced positive results whether they were assigned to a group instructed to perform high-intensity or low-intensity exercise (King et al. 1993). With the varying research available detailing specific dosage, it appears to be a consensus that anything helps. For optimal physical and psychological benefits, clinicians generally recommend moderate-intensity exercise for at least 150 minutes per week (Trivedi et al. 2011).

Potential Psychological Consequences of Exercise

In light of the plentiful data on psychological benefits of exercise, one must wonder if there are any negative consequences. In some cases, people can develop exercise dependence, in which exercise becomes a compulsion that interferes with daily life and relationships. Since exercise releases endorphins, and such opiodergic activity is also involved in addiction, there could be a relationship between endorphin release and exercise dependence (Leuenberger 2006). In addition, individuals who take part in regular exercise and then experience an interruption in their routine due to injury or other factors could experience negative psychological effects. One study of runners found that those who were deprived of running for two weeks experienced greater levels of psychological distress, such as depression, anxiety, and lowered self-esteem, than those who experienced no interruption in their training (Chan and Grossman 1988). It is generally agreed upon that exercise deprivation among habitual exercisers induces a negative psychological response, but it is difficult to recruit individuals for further study who are willing to give up their habits long enough to participate (Szabo 1995).

Conclusion

The many benefits of exercise clearly apply to the mind as well as the body, whether it’s a short-term rush from the release of endorphins from a good run, or a powerful weapon against the long-term effects of clinical depression. Not only does it promote happiness and well-being, it also helps the brain perform better and ward off cognitive decline as we age. It is apparent that regular exercise can do little but help your brain achieve its potential. If the motivation of a strong body is not enough to initiate a workout plan, considering the brain could be a helpful tool in maintaining a healthy lifestyle with plenty of physical activity.

By Alycia Parnell
Alycia Parnell holds degrees in Psychology and Environmental Studies from the University of Utah. She lives, works, and writes in Salt Lake City.

Literature Cited 

  1. Boecker, H., T. Sprenger, M.E. Spilker, G. Henriksen, M. Koppenhoefer, K.J. Wagner, M. Valet, A. Berthele, and T.R. Tolle. 2008. The runner’s high: opioidergic mechanisms in the human brain. Cerebral Cortex, 18: 2523-2531.
  2. Chan, C.S., and H.Y. Grossman. 1988. Psychological effects of running loss on consistent runners. Perceptual and Motor Skills 66: 875-883.
  3. Comery T.A., C.X. Stamoudis, S.A. Irwin, and W.T. Greenough. 1996. Increased density of multiple-head dendritic spines on medium-sized spiny neurons of the striatum in rats reared in a complex environment. Neurobiology of Learning and Memory 66: 93–96.
  4. Dearman, J., and K.T. Francis. 1983. Plasma levels of catecholamines, cortisol, and beta-endorphins in male athletes after running 26.2, 6, and 2 miles. The Journal of Sports Medicine and Physical Fitness  23: 30-38.
  5. De Moor, M.H, A.L. Beem, J.H. Stubbe, D.I. Boomsma, and E.J. De Geus. 2006. Regular exercise, anxiety, depression and personality: a population-based study. Preventive medicine 42: 273-279.
  6. Dietrich, A., and W.F. McDaniel. 2004. Endocannabinoids and exercise. British Journal of Sports Medicine 38: 536-541.
  7. Hamer, M., and Y. Chida. 2009. Physical activity and risk of neurodegenerative disease: a systematic review of prospective evidence. Psychological Medicine 39: 3.
  8. Hassmén, P., N. Koivula, and A. Uutela. 2000. Physical exercise and psychological well-being: a population study in Finland. Preventive Medicine 30: 17-25.
  9. King, A.C., C.B. Taylor, and W.L. Haskell. 1993. Effects of differing intensities and formats of 12 months of exercise training on psychological outcomes in older adults. Health Psychology 12: 292.
  10. Kramer, A.F., S. Hahn, N.J. Cohen, M.T. Banich, E. McAuley, C.R. Harrison, J. Chason, E. Vakill, L. Bardell, R.A. Boileau, and A. Colcombe. 1999. Ageing, fitness and neurocognitive function. Nature 400: 418-419.
  11. Leuenberger, A. 2006. Endorphins, exercise, and addictions: a review of exercise dependence. Impulse: the Premier Journal for Undergraduate Publications in the Neurosciences 3: 1-9.
  12. Levinthal, C.F. 2008. Drugs, behavior, and modern society. Pearson, Boston, MA.
  13. Mattson, M.P., W. Duan, R. Wan, and Z. Guo. 2004. Prophylactic activation of neuroprotective stress response pathways by dietary and behavioral manipulations. NeuroRx 1: 111-116.
  14. McGovern, M. K. 2005. The effects of exercise on the brain. Serendip Studio. Bryn Mawr College. <http://198.252.64.61/Support/Studies/The Effects of Exercise on the Brain,,BDNF.pdf>
  15. Szabo, A. 1995. The impact of exercise deprivation on well-being of habitual exercisers. Australian Journal of Science and Medicine in Sport 27: 68-77.
  16. Teri, L., L.E. Gibbons, S.M. McCurry, R.G. Logsdon, D.M. Buchner, W.E. Barlow, W.A. Kukull, A.Z. LaCroix, W. McCormick, and E.B. Larson. 2003. Exercise plus behavioral management in patients with Alzheimer disease: a randomized controlled trial. Jama 290: 2015-2022.
  17. Trivedi, M.H., T.L. Greer, T.S. Church, T.J. Carmody, B.D. Grannemann, D.I. Galper, A.L. Dunn, C.P. Earnest, P. Sunderajan, S.S. Henley, and S.N. Blair. 2011. Exercise as an augmentation treatment for nonremitted major depressive disorder: a randomized, parallel dose comparison. Journal of Clinical Psychiatry 72: 677.
  18. Zheng, H., Y. Liu, W. Li, B. Yang, D. Chen, X. Wang, Z. Jiang, H. Wang, Z.Wang, G. Cornelisson, and f. Halberg. 2006. Beneficial effects of exercise and its molecular mechanisms on depression in rats. Behavioural Brain Research 168: 47-55.

Timing of Eating and Exercise (Basic)

Introduction

An important area in the realm of sports nutrition is the timing of food and fluid consumption around exercise. In general, nutrition guidelines for athletes for each of the macronutrients are as follows: 6-10 grams carbohydrate per kilogram body weight per day, 1.2- 1.7 grams protein per kilogram body weight per day, and 20%-30% of total daily energy from fat (Rodriguez et. al 2009). The specific recommendations for each time frame surrounding exercise are detailed below.

Before Exercise

Eating before exercise has been shown to improve exercise performance when compared to exercising in a fasted state (Maffucci and McMurray 2000, Jentjens et al. 2003, Mosely et al. 2003). In regard to the composition of the pre-exercise meal or snack, it is recommended that it be high in carbohydrates, low in fat, moderate in protein, low in fiber, provide adequate fluid, and be familiar to the athlete (Rodriguez et. al 2009).

In general, larger meals can be consumed when there is a greater time gap between eating and exercise, whereas smaller amounts should be consumed if eating and exercise are in close proximity. In terms of carbohydrate, it is recommended that 1-4 grams carbohydrate per kilogram body weight be consumed 1-4 hours prior to exercise (Sugiura and Kobayashi 1998). For fluid needs, at least four hours prior to exercise it is recommended that water or a sports drink be consumed in the amount of approximately 5-7 milliliters per kilogram body weight (Rodriguez et. al 2009).

During Exercise

Fueling during exercise is of greatest importance during prolonged exercise. For exercise bouts lasting less than 45-60 minutes, water is generally sufficient. However, endurance performance has been shown to be benefited with drinking sports beverages that contain 6-8% carbohydrate during exercise (Coggan and Coyle 1991, Nicholas et al. 1995, Jeukendrup et al. 1997). For events lasting longer than one hour it is recommended that carbohydrate intake be in the range of 30-60 grams carbohydrate per hour, or 0.7 grams carbohydrate per kilogram body weight per hour (McConell et al. 1996, Currell and Jeukendrup 2008). Carbohydrates may be obtained from food, gels, or sports beverages, the latter option also providing needed fluid.

In regard to fluid intake during exercise, specific general recommendations for fluid replacement during exercise have not been established, as these general guides would likely be inappropriate for many situations (Sawka et al. 2007). Thus, fluid intake should be determined for each athlete individually based on the length of exercise, sweat rate, and opportunities to drink (Rodriguez et. al 2009).

After Exercise

The period immediately following exercise is a time when the body is best positioned to restore glycogen (the storage form of carbohydrates in the body) at the highest rate (Sugiura and Kobayashi 1998). It is recommended that carbohydrates be consumed within 30 minutes after exercise and that 1.5 grams carbohydrate per kilogram be consumed in the first hour following exercise (Ivy et al. 1988, Sugiura and Kobayashi 1998). Adding protein as part of a meal after exercise may be beneficial in regard to muscle protein synthesis and repair (Rodriguez et al. 2007, van Loon et al. 2013). In regard to specific amounts or time frames for protein ingestion surrounding exercise, additional research is needed (van Loon et al. 2013).

If recovery time is not limited, normal meals, snacks, and water intake should be sufficient to replenish fluids lost. In situations where recovery time is limited, or there is excess dehydration, 1.5 liters of fluid for each kilogram of body weight lost should be consumed (Sawka et al. 2007).

Conclusion

When attempting to meet nutrition needs, the timing of eating surrounding exercise is an important consideration. Appropriate meal timing and composition before, during, and after exercise can assist in improving athletic performance.

By: Jamie Saunders, University of Utah

Read the more technical details of timing your food intake around exercise.

Literature Cited

Coggan, A. R., and E. F. Coyle. 1991. Carbohydrate ingestion during prolonged exercise: Effects on metabolism and performance. Exerc Sport Sci Rev 19:1-40.

Currell, K., and A. E. Jeukendrup. 2008. Superior endurance performance with ingestion of multiple transportable carbohydrates. Med Sci Sport Exerc 40:275-281.

Ivy, J. L., A. L. Katz, C. L. Cutler, W. M. Sherman, and E. F. Coyle. 1988. Muscle glycogen synthesis after exercise: Effect of time of carbohydrate ingestion. J Appl Physiol 64:1480-1485.

Jentjens R. L., C. Cale, C. Gutch, and A. E. Jeukendrup. 2003. Effects of pre-exercise ingestion of differing amounts of carbohydrate on subsequent metabolism and cycling performance. European Journal of Applied Physiology. 88:444-452.

Jeukendrup, A., F. Grouns, A. J. Wagenmakers, and W. H. Saris. 1997. Carbohydrate-electrolyte feedings improve1 h time trial cycling performance. Int J Sports Med 18:125-129.

Maffucci, D. M., and R. G. McMurray. 2000. Towards optimizing the timing of the pre-exercise meal. International Journal of Sport Nutrition and Exercise Metabolism 10(2):103-113.

McConell, G., K. Kloot, and M. Hargreaves. 1996. Effect of timing of carbohydrate ingestion on endurance exercise performance. Med Sci Sports Exerc 28:1300-1304.

Moseley L., G. I. Lancaster, and A. E. Jeukendrup. 2003. Effects of timing of pre-exercise ingestion of carbohydrate on subsequent metabolism and cycling performance. European Journal of Applied Physiology. 88:453-458.

Nicholas, C. W., C. Williams, H. K. Lakomy, G. Phillips, and A. Nowitz. 1995. Influence of ingesting a carbohydrate-electrolyte solution on endurance capacity during intermittent, high-intensity shuttle running. J Sports Sci 13:283-290.

Rodriguez, N. R., L. M. Vislocky, and P. C. Gaine. 2007. Dietary protein, endurance, exercise, and human skeletal-muscle protein turnover. Curr Opin Clin Nutr Metab Care 10:40-45.

Rodriquez, N. R., N. M. DiMarco, L. Langley, American Dietetic Association, Dietitians of Canada, & the American College of Sports Medicine. 2009. Nutrition and athletic performance. Journal of the American Dietetic Association. 109(3): 509-527.

Sawka, M. N., L. M. Burke, E. R. Eichner, R. J. Maughan, S. J. Montain, and N. S. Stachenfeld. 2007. American college of sports medicine position stand: Exercise and fluid replacement. Medicine and Science in Sports and Exercise 39:377-390.

Sugiura K., and K. Kobayashi. 1998. Effect of carbohydrate ingestion on sprint performance following continuous and intermittent exercise. Med Sci Sports Exerc 30:1624-1630.

van Loon, L. J. C., T. D. Tipton KD, and L. J. C. van Loon (eds). 2013. Role of dietary protein in post-exercise muscle reconditioning. Nutritional Coaching Strategy to Modulate Training Efficiency. Nestlé Nutr Inst Workshop Ser. Nestec Ltd. Vevey/S. Karger AG Basel 75:73-83.

Timing of Eating and Exercise (Technical)

The role of nutrition in regard to physical activity and athletic performance is of high importance for all athletes. There are many aspects to consider in the realm of sports nutrition, and an important area is the timing of food and fluid consumption around exercise. The research in this area points to several specific guidelines to assist athletes in optimizing their performance by not only consuming the proper nutrients, but also consuming them in the appropriate time frame around exercise.

In general, nutrition guidelines for athletes for each of the macronutrients are as follows: 6-10 grams carbohydrate per kilogram body weight per day, 1.2- 1.7 grams protein per kilogram body weight per day, and 20% to 30% of total daily energy from fat (Rodriguez et al. 2009). For maximum benefit, spacing the consumption of each of these nutrients appropriately is essential. Each of these nutrients plays a specific role in regard to physical activity.

Carbohydrates are the body’s preferred source of energy, and consumption of carbohydrates is beneficial in supporting activity. Ingesting carbohydrates assists with the maintenance of blood glucose levels during exercise, and also replenishes muscle glycogen (the storage form of carbohydrates in the body; Dunford and Doyle 2012). The specific recommendations for total daily carbohydrate intake based on training load and type of exercise are shown in Table 1 (Nutrition Booklet 2010).

Table 1.

Training Load Type of Exercise Carbohydrate Intake Targets (g/kg body mass)
Light Low intensity or skill-based activities 3-5 g/kg/d
Moderate Moderate exercise program (i.e. ~1 hour per day) 5-7 g/kg/d
High Endurance program (e.g. 1-3 hours per day of mod-high-intensity exercise) 6-10 g/kg/d
Very High Extreme commitment (i.e., at least 4-5 hours per day of mod-high intensity exercise) 8-12 g/kg/d

Protein has many unique functions in the body, however protein can only be used for these important roles when there is sufficient caloric intake from carbohydrates and fat (Dunford and Doyle 2012). Though the body can use protein for energy, consuming sufficient carbohydrates will provide a protein-sparing effect. This means that protein will not be converted to energy, and can instead be used to carry out its other important functions in the body, such as tissue maintenance and repair, nutrient transport, muscle protein synthesis, and so forth (Gropper et al. 2008).

Fat is a necessary nutrient for athletes, and together with carbohydrate acts as an important energy source for moderate-intensity exercise. Fat provides essential fatty acids, and allows absorption of fat soluble vitamins (Mahan and Escott-Stump 2008). Careful consideration is required to allow sufficient but not excessive fat intake. Of particular concern is that fat slows gastric emptying and takes longer to digest than either carbohydrates or protein, so the timing of fat intake around exercise is a key factor to consider in meal planning (Dunford and Doyle 2012).

As has been demonstrated, each macronutrient plays a key role in exercise performance, and the timing of intake for each of these nutrients is an important consideration. The specific recommendations for food and fluid intake within each time frame surrounding exercise are detailed below.

Before Exercise

In sports nutrition, the recommendations for nutrition prior to exercise generally refers to the time frame approximately four hours before exercise begins (Dunford and Doyle 2012). Though overall nutrition status plays a role in athletic performance, this time frame has the most immediate impact on the upcoming bout of exercise. Fueling before exercise is important as improvement in exercise performance has been shown when food is ingested prior to exercise, as compared to exercising in a fasted state (Maffucci and McMurray 2000, Jentjens et al. 2003, Mosely et al. 2003).

There are several purposes to fueling the body appropriately before exercise. Though maximizing performance is the key benefit, avoiding gastrointestinal distress during exercise, maintaining blood glucose levels, and avoiding excessive or inadequate hydration are other purposes for fueling properly prior to exercise. Though fatigue during exercise cannot be prevented, the onset of fatigue can be delayed with proper fueling before exercise (Dunford and Doyle 2012). In order to accomplish these purposes, it is recommended that the pre-exercise meal or snack should be of a particular composition. In regard to macronutrients, it should be high in carbohydrates, low in fat, and moderate in protein. Other important considerations include low fiber options and adequate fluid consumption (Rodriguez et al. 2009).

The total amount of food consumed before exercise will be determined by the time between eating and the onset of exercise. The general guide is that larger meals can be consumed when there is a greater time gap between eating and exercise, whereas smaller amounts of food should be consumed if eating and exercise are in close proximity. In terms of carbohydrate, it is often recommended that 1-4 grams carbohydrate per kilogram body weight be consumed 1-4 hours prior to exercise (1 gram per kilogram if 1 hour prior, 2 grams per kilogram if 2 hours prior, etc.; Dunford and Doyle 2012). The key to pre-exercise feedings is that the athlete should start the exercise bout without feeling hungry, but also without food in the stomach that is undigested. As each athlete will tolerate various foods differently, the most important consideration with pre-exercise meals is that they should be familiar to the athlete, and new foods should be tried during training sessions before being used in competition settings (Rodriguez et al. 2009).

Considerations in regard to fluid intake include achieving sufficient hydration, while allowing sufficient time for fluid voiding prior to exercise. At least four hours prior to exercise it is recommended that water or a sports drink be consumed in the amount of approximately 5 to 7 milliliters per kilogram body weight (Rodriguez et al. 2009).

4673-clocks-81During Exercise

The ingestion of nutrients during exercise becomes of greatest importance during prolonged exercise. The purposes of fueling during exercise include maximizing performance, delaying fatigue, managing fluid and electrolyte balance, and avoiding gastrointestinal distress (Dunford and Doyle 2012). The composition and timing of the pre-exercise meal contributes to the determination of proper fueling during exercise. Of the body of research available, the two aspects of most importance for consumption during exercise include fluid and carbohydrate replacement.  For exercise bouts lasting less than 45-60 minutes, water is generally sufficient. However, endurance performance has been shown to be benefited with sports beverages that contain 6-8 percent carbohydrate, and this composition is appropriate for ingestion during exercise (Nicholas et al. 1995, Jeunjendrup et al. 1997, Sugiura and Kobayashi 1998). For events lasting longer than one hour it is recommended that carbohydrate intake be in the range of 30-60 grams carbohydrate per hour, or 0.7 grams carbohydrate per kilogram body weight per hour (Coggan and Coyle 1991, Currell and Jeukendrup 2008).

Though total carbohydrate ingestion is important, the type of carbohydrate consumed is another relevant consideration. Evidence suggests that fructose alone may not be tolerated or used as effectively as other forms of carbohydrate, such as mixtures of glucose and fructose, other simple sugars, and maltodextrins (Coggan and Coyle 1991). Carbohydrates may be obtained from food, gels, or sports beverages, the latter option also providing needed fluid. If carbohydrates are consumed from food or gels, water should also be consumed to maintain hydration status during exercise.

It is beneficial to begin carbohydrate ingestion shortly after beginning exercise, rather than waiting until later in the exercise bout. Additionally, the timing of carbohydrate consumption during exercise has been shown to be more effective when ingested every 15 to 20 minutes throughout activity rather than as a single bolus (McConell et al. 1996, Rodriguez et al. 2009).

In regard to fluid intake during exercise, the goal is to prevent dehydration, particularly fluid losses in excess of two percent of body weight. The regimen for fluid replacement should be determined based on individual sweat rate, environmental conditions, opportunities to drink, and the duration and intensity of exercise (Sawka et al. 2007). The American College of Sports Medicine has not established specific general recommendations for fluid replacement during exercise, as these general guides would likely be inappropriate for many situations and could lead to significant under- or over-consumption of fluid, which could have detrimental effects (Sawka et al. 2007).

After Exercise

The significance of the post-exercise meal is determined largely by the length of time until the next exercise bout, as well as the duration and intensity of activity. The purpose of the meal after exercise is to replenish glycogen stores, repair muscle protein, replace fluid and electrolyte losses, and aid in overall recovery (Dunford and Doyle 2012).

The timing of the post-exercise meal in regard to replenishing glycogen stores is of most importance if the next exercise bout will occur in twelve hours or less, however the period immediately following exercise is a time frame when the body is best positioned to restore glycogen stores at the highest rate (Dunford and Doyle 2012). Delaying carbohydrate intake can significantly reduce glycogen synthesis (Ivy 1998). In light of this, it is generally recommended that carbohydrates be consumed within 30 minutes after exercise and that 1.5 grams carbohydrate per kilogram be consumed in the first hour following exercise (Ivy et al. 1998, Dunford and Doyle 2012). In regard to the type of carbohydrate, fructose alone is less effective than either glucose or sucrose (Blom et al. 1987).

Other macronutrient considerations do not necessarily impact the rate of glycogen synthesis, however they may have other benefits. Adding protein as part of a meal after exercise may be beneficial in regard to muscle protein repair (Rodriguez et al. 2007). In order to increase the rate of muscle protein synthesis after exercise, it is requisite to consume protein in the period following exercise (van Loon et al. 2013). In regard to specific amounts of protein and a specific time frame for protein ingestion surrounding exercise, additional research is required in this area (van Loon et al. 2013).

In regard to fluid needs post-exercise, recovery time is once again the key. If recovery time is not limited normal meals, snacks, and water intake should be sufficient to replenish fluid that has been lost. In situations where recovery time is limited, or there is excess dehydration, 1.5 liters of fluid for each kilogram of body weight lost should be consumed (Sawka et al. 2007). Body weight lost can be determined using pre- and post-exercise weighing. It is preferable to drink the recommended amount over time rather than as a larger bolus to assist in rehydration(Wong et al. 1998, Kovacs et al. 2002).

Though post-exercise nutrition recommendations may be difficult to implement due to other demands and factors (sleep due to fatigue, returning to school or work after training, decreased appetite, etc.), this is a critical time to replenish nutrient stores and set up properly for the next bout of exercise (Dunford and Doyle 2012).

Conclusion

In sum, when attempting to meet nutrition needs the timing of eating surrounding exercise is an important consideration. Appropriate meal timing and composition before, during, and after exercise can assist in improving athletic performance. 

By: Jamie Saunders, University of Utah
Jamie Saunders has always been interested in the area of nutrition and wellness. Saunders graduated from Southern Utah University with a Bachelor’s degree in Human Nutrition, and from the University of Utah’s Coordinated Master’s Program in Dietetics, with an emphasis in Sports Dietetics. She is a Registered Dietitian and currently works as the Outpatient Dietitian for the University Health Care’s South Jordan Health Center.

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