Creatine ingestion favorably affects performance and muscle metabolism during maximal exercise in humans. Vandenberghe, K. Long-term creatine intake is beneficial to muscle performance during resistance training. Hermansen, L. Muscle glycogen during prolonged severe exercise. Muscle glycogen stores and fatigue. Matsui, T. Brain glycogen decreases during prolonged exercise. Diet, muscle glycogen and physical performance. Carbohydrate-loading and exercise performance: an update.
Balsom, P. High-intensity exercise and muscle glycogen availability in humans. Muscle glycogen utilization during prolonged strenuous exercise when fed carbohydrate. Reversal of fatigue during prolonged exercise by carbohydrate infusion or ingestion. Effect of carbohydrate ingestion on exercise metabolism. Jeukendrup, A. Carbohydrate ingestion can completely suppress endogenous glucose production during exercise. Effect of carbohydrate ingestion on glucose kinetics during exercise.
Nybo, L. CNS fatigue and prolonged exercise: effect of glucose supplementation. Snow, R. Effect of carbohydrate ingestion on ammonia metabolism during exercise in humans. Chambers, E. Carbohydrate sensing in the human mouth: effects on exercise performance and brain activity.
Costill, D. Effects of elevated plasma FFA and insulin on muscle glycogen usage during exercise. Vukovich, M. Effect of fat emulsion infusion and fat feeding on muscle glycogen utilization during cycle exercise. Odland, L. Effects of increased fat availability on fat-carbohydrate interaction during prolonged exercise in men. Phinney, S. The human metabolic response to chronic ketosis without caloric restriction: preservation of submaximal exercise capability with reduced carbohydrate oxidation.
Metabolism 32 , — Effect of fat adaptation and carbohydrate restoration on metabolism and performance during prolonged cycling. Havemann, L. Fat adaptation followed by carbohydrate loading compromises high-intensity sprint performance. Decreased PDH activation and glycogenolysis during exercise following fat adaptation with carbohydrate restoration. Low carbohydrate, high fat diet impairs exercise economy and negates the performance benefit from intensified training in elite race walkers.
Paoli, A. The ketogenic diet and sport: a possible marriage. Ketogenic diets for fat loss and exercise performance: benefits and safety? Helge, J. Interaction of training and diet on metabolism and endurance during exercise in man. Yeo, W. Skeletal muscle adaptation and performance responses to once a day versus twice every second day endurance training regimens.
Hulston, C. Training with low muscle glycogen enhances fat metabolism in well-trained cyclists. Kirwan, J. Carbohydrate balance in competitive runners during successive days of intense training. Cox, P. Nutritional ketosis alters fuel preference and thereby endurance performance in athletes.
Shaw, D. Exogenous ketone supplementation and keto-adaptation for endurance performance: disentangling the effects of two distinct metabolic states. Evans, M. No benefit of ingestion of a ketone monoester supplement on km running performance. Prins, P. Effects of an exogenous ketone supplement on five-kilometer running performance.
Dearlove, D. Nutritional ketoacidosis during incremental exercise in healthy athletes. Leckey, J. Ketone diester ingestion impairs time-trial performance in professional cyclists. Effects of caffeine ingestion on metabolism and exercise performance. Sports 10 , — Graham, T.
Performance and metabolic responses to a high caffeine dose during prolonged exercise. Caffeine ingestion and muscle metabolism during prolonged exercise in humans. Caffeine ingestion does not alter carbohydrate or fat metabolism in human skeletal muscle during exercise. Metabolic, catecholamine, and exercise performance responses to various doses of caffeine. Desbrow, B.
The effects of different doses of caffeine on endurance cycling time trial performance. Sports Sci. Cole, K. Effect of caffeine ingestion on perception of effort and subsequent work production. Sport Nutr. Kalmar, J. Caffeine: a valuable tool to study central fatigue in humans? Exercise and sport performance with low doses of caffeine. Suppl 2. Wickham, K. Administration of caffeine in alternate forms.
Barnett, C. Effect of L-carnitine supplementation on muscle and blood carnitine content and lactate accumulation during high-intensity sprint cycling.
Stephens, F. Carbohydrate ingestion augments L-carnitine retention in humans. Wall, B. Chronic oral ingestion of L-carnitine and carbohydrate increases muscle carnitine content and alters muscle fuel metabolism during exercise in humans. Skeletal muscle carnitine loading increases energy expenditure, modulates fuel metabolism gene networks and prevents body fat accumulation in humans. A threshold exists for the stimulatory effect of insulin on plasma L-carnitine clearance in humans. Larsen, F.
Effects of dietary nitrate on oxygen cost during exercise. Bailey, S. Dietary nitrate supplementation reduces the O 2 cost of low-intensity exercise and enhances tolerance to high-intensity exercise in humans. Dietary nitrate supplementation enhances muscle contractile efficiency during knee-extensor exercise in humans. Lansley, K. Acute dietary nitrate supplementation improves cycling time trial performance. Boorsma, R. Beetroot juice supplementation does not improve performance of elite m runners.
Nyakayiru, J. No effect of acute and 6-day nitrate supplementation on VO 2 and time-trial performance in highly trained cyclists. Jones, A. Dietary nitrate and physical performance. Whitfield, J. Dietary nitrate enhances the contractile properties of human skeletal muscle. Beetroot juice supplementation reduces whole body oxygen consumption but does not improve indices of mitochondrial efficiency in human skeletal muscle.
Dietary inorganic nitrate improves mitochondrial efficiency in humans. Ntessalen, M. Inorganic nitrate and nitrite supplementation fails to improve skeletal muscle mitochondrial efficiency in mice and humans.
Relationship of contraction capacity to metabolic changes during recovery from a fatiguing contraction. Sutton, J. Effect of pH on muscle glycolysis during exercise. Wilkes, D. Effect of acute induced metabolic alkalosis on m racing time. Acid-base balance during repeated bouts of exercise: influence of HCO 3. Hollidge-Horvat, M. Effect of induced metabolic alkalosis on human skeletal muscle metabolism during exercise. Street, D. Metabolic alkalosis reduces exercise-induced acidosis and potassium accumulation in human skeletal muscle interstitium.
Sostaric, S. Parkhouse, W. Buffering capacity of deproteinized human vastus lateralis muscle. Derave, W. Hill, C. Amino Acids 32 , — Powers, S. Exercise-induced oxidative stress: cellular mechanisms and impact on muscle force production. Merry, T. Do antioxidant supplements interfere with skeletal muscle adaptation to exercise training? Petersen, A. Infusion with the antioxidant N-acetylcysteine attenuates early adaptive responses to exercise in human skeletal muscle.
Ristow, M. Antioxidants prevent health-promoting effects of physical exercise in humans. Natl Acad. USA , — Hyperthermia and fatigue.
Dehydration markedly impairs cardiovascular function in hyperthermic endurance athletes during exercise. Metabolic and thermodynamic responses to dehydration-induced reductions in muscle blood flow in exercising humans.
Fink, W. Leg muscle metabolism during exercise in the heat and cold. Febbraio, M. Muscle metabolism during exercise and heat stress in trained men: effect of acclimation. Blunting the rise in body temperature reduces muscle glycogenolysis during exercise in humans. Influence of body temperature on the development of fatigue during prolonged exercise in the heat.
Effect of fluid ingestion on muscle metabolism during prolonged exercise. Logan-Sprenger, H. Effects of dehydration during cycling on skeletal muscle metabolism in females. Skeletal muscle enzymes and fiber composition in male and female track athletes.
Lipid metabolism in skeletal muscle of endurance-trained males and females. Horton, T. Fuel metabolism in men and women during and after long-duration exercise. Friedlander, A.
Training-induced alterations of carbohydrate metabolism in women: women respond differently from men. Tarnopolsky, L. Gender differences in substrate for endurance exercise. Carter, S. Substrate utilization during endurance exercise in men and women after endurance training.
Roepstorff, C. Gender differences in substrate utilization during submaximal exercise in endurance-trained subjects. Hamadeh, M. Estrogen supplementation reduces whole body leucine and carbohydrate oxidation and increases lipid oxidation in men during endurance exercise.
Hackney, A. Substrate responses to submaximal exercise in the midfollicular and midluteal phases of the menstrual cycle. Zderic, T. Glucose kinetics and substrate oxidation during exercise in the follicular and luteal phases. Devries, M. Menstrual cycle phase and sex influence muscle glycogen utilization and glucose turnover during moderate-intensity endurance exercise. Frandsen, J. Menstrual cycle phase does not affect whole body peak fat oxidation rate during a graded exercise test.
Download references. You can also search for this author in PubMed Google Scholar. Correspondence to Mark Hargreaves or Lawrence L. Reprints and Permissions.
Skeletal muscle energy metabolism during exercise. Nat Metab 2, — Download citation. Received : 20 April Accepted : 25 June Published : 03 August Issue Date : September Anyone you share the following link with will be able to read this content:.
Sorry, a shareable link is not currently available for this article. Provided by the Springer Nature SharedIt content-sharing initiative. Journal of the International Society of Sports Nutrition Scientific Reports European Journal of Applied Physiology Journal of Ambient Intelligence and Humanized Computing Advanced search.
Skip to main content Thank you for visiting nature. Download PDF. Subjects Energy metabolism Skeletal muscle. This article has been updated. Abstract The continual supply of ATP to the fundamental cellular processes that underpin skeletal muscle contraction during exercise is essential for sports performance in events lasting seconds to several hours.
Main In , athletes from around the world were to gather in Tokyo for the quadrennial Olympic festival of sport, but the event has been delayed until because of the COVID pandemic. Overview of exercise metabolism The relative contribution of the ATP-generating pathways Box 1 to energy supply during exercise is determined primarily by exercise intensity and duration. Full size image. Regulation of exercise metabolism General considerations Because the increase in metabolic rate from rest to exercise can exceed fold, well-developed control systems ensure rapid ATP provision and the maintenance of the ATP content in muscle cells.
Box 3 Sex differences in exercise metabolism One issue in the study of the regulation of exercise metabolism in skeletal muscle is that much of the available data has been derived from studies on males. Targeting metabolism for ergogenic benefit General considerations Sports performance is determined by many factors but is ultimately limited by the development of fatigue, such that the athletes with the greatest fatigue resistance often succeed.
Training Regular physical training is an effective strategy for enhancing fatigue resistance and exercise performance, and many of these adaptations are mediated by changes in muscle metabolism and morphology.
Carbohydrate loading The importance of carbohydrate for performance in strenuous exercise has been recognized since the early nineteenth century, and for more than 50 years, fatigue during prolonged strenuous exercise has been associated with muscle glycogen depletion 13 , High-fat diets Increased plasma fatty acid availability decreases muscle glycogen utilization and carbohydrate oxidation during exercise , , Ketone esters Nutritional ketosis can also be induced by the acute ingestion of ketone esters, which has been suggested to alter fuel preference and enhance performance Caffeine Early work on the ingestion of high doses of caffeine 6—9 mg caffeine per kg body mass 60 min before exercise has indicated enhanced lipolysis and fat oxidation during exercise, decreased muscle glycogen use and increased endurance performance in some individuals , , The friction between the tyres and the road will also cause the tyres to warm up a little producing thermal energy.
What form will some of this energy take when putting on the brakes? Types of Energy. Read More: Fuel For Humans. Renewable Energy Factsheet. How is electricity made?
Renewable Energy Video. Environment Factsheet. Renewable Energy: Biomass Energy Factsheet. Renewable Energy: Solar Energy Factsheet.
Conservation Education 13 - Energy Download. Oil Pollution Case Study Factsheet. Pollution Factsheet. Global Warming Factsheet. The interrelation of various field methods may be of some value, but because there are errors in all methods it is impossible to determine the true validity of any one of them in doing so Montoye et al.
However, the doubly labeled water method has become the gold standard for the validation of field methods of assessing physical activity Melanson and Freedson, The indicated alternative for doubly labeled water, to assess the PAL of a subject in daily life, is a doubly labeled water validated accelerometer.
Accelerometers can be used to study patterns of activity in time. Simultaneous measurement of body acceleration and heart rate can give information on physical fitness Plasqui and Westerterp, Behavioral observation and questionnaires, as a self-report method, can be adequately used as an activity-ranking instrument Westerterp, Young children have a low PAL.
The increase is reflected in the increase of the PAL from 1. It seems young children have a lower activity expenditure and PAL because it takes less energy to move around with a lower body weight.
Accelerometers provide information on the activity pattern including activity intensity. Despite the constancy of activity energy expenditure adjusted for body weight from childhood to adulthood, the movement pattern clearly differs. Young children spend more of their active time on high intensity activities Hoos et al. The difference in time spent on high intensity activities between children and adults reflects the different activity patterns among children, which are characterized by short, intermittent bouts of vigorous activity.
Probably because of their lower body weight it is easier for children to perform high intensity activities. Physical activity of an year subject is on average not different from physical activity in a year subject. After age 50, physical activity generally declines, in women as well as men, resulting in a mean PAL of about 1. A PAL of 1. At age 90, one does not go out very often anymore.
The activity pattern of elderly subjects is characterized by low intensity activities Meijer et al. There is a limited number of exercise training studies where the PAL was measured with doubly labeled water, before and at the end of the training intervention. Combining the data of the studies by plotting the PAL in a sequence of the age of the subjects, there are some clear observations to make Figure 5.
The PAL before training ranges from lower values around 1. Exercise training induces an increase in physical activity in younger subjects but not in older subjects. The exception is a training study in year subjects; however, in this study training was combined with energy restriction to induce weight loss.
In younger subjects, the mean physical activity values reached a ceiling value around 2. No training study reported individual PAL values over 2. Thus, exercise training induces an increase in physical activity when one is young or middle-aged and eats ad libitum. The physical activity level, total energy expenditure as a multiple of basal energy expenditure, before open bar and at the end of a training program closed bar , for eight studies displayed in a sequence of age of the participants as indicated on the horizontal axis.
The horizontal broken lines denote the average physical activity level of 1. The lack of an effect of exercise training on the physical activity can only be explained by a compensatory reduction of physical activity in the non-training time.
Observations with accelerometers have shown imposed exercise training did not influence spontaneous activity in younger subjects so that their total PALs increased Meijer et al. In contrast, elderly subjects compensate for exercise training by a decline in spontaneous physical activity, so that PALs remain unchanged Meijer et al.
A potential explanation for a compensatory reduction of physical activity in the non-training time is a negative energy balance. PAL did not increase when exercise training was combined with an energy-restricted diet Kempen et al. The PAL in elderly subjects might not respond to exercise training because of a limitation through energy intake, as indicated by a study of the effect of age on energy balance Ainsli et al.
Exposing year and year subjects to the same strenuous hill walking activity for 10 days resulted in a similar expenditure of about The PAL reaches a maximum value of 2. However, professional endurance athletes can reach a value around 4. They are a selection of the population, born to be athletes, training for many years to reach their high level of performance. The training includes exercise and the maintenance of energy balance at a high level of energy turnover.
The latter implicates the supplementation of the diet with energy drinks. Some can quietly sit and read for hours while others do not have the perseverance to be quiet. Surprisingly, between subjects variation in physical activity is also large within the identical confined space of a respiration chamber, indicating an effect of predisposition Westerterp and Kester, The mean PAL of the subjects in the chamber was 1.
However, the minimum value was as low as 1. There was a subject with an AEE of 1. Subjects with a relatively low or high PAL in the respiration chamber turned out to be, respectively, relatively sedentary or physically active in free-living conditions as well Figure 6. Further studies, as described below, provided evidence for an important genetic component in the threefold variation in AEE among individuals in the same confined environment of a respiration chamber and the significant relation with PAL in free-living conditions.
Free-living physical activity level plotted as a function of physical activity level in the confined environment of a respiration chamber, with the line of identity dotted and the linear regression line continuous After Westerterp and Kester, The test for a genetic contribution was based on a classic twin design.
Intrapair differences in monozygotic twins are due to environmental factors and measurement errors, whereas intrapair differences in dizygotic twins are additionally affected by genetic factors. Physical activity was measured over two consecutive weeks with a doubly labeled water validated tri-axial accelerometer for the measurement of movement. The PAL was significantly related within twin pairs and the relation was nearly twice as strong within monozygotic than within dizygotic twins. Thus, a large part of the variation in physical activity between subjects can be ascribed to predisposition.
The relatively high contribution of a genetic component to variation in physical activity does not automatically imply subjects with high predisposition for a sedentary life style are less active than subjects with a predisposition for an active life style. The ultimate activity level is the outcome of an interaction between genes and environment.
It only takes more effort for subjects with a predisposition for a sedentary life style to reach the same activity level as for those with predisposition for an active life style. Physical activity implies displacement of the weight of a body part like arms, legs, or the full body. Together with activity duration and intensity, body weight determines the variation in AEE. The effect of body weight on physical activity is illustrated by activity changes during growth from birth to adult weight, physical activity and underweight in anorectic subjects, and physical activity and overweight in obese subjects.
Body weight increases from three to four kg at birth to an adult value of 60 to 70 kg. Activity energy expenditure adjusted for body weight does not show a systematic increase, as explained in section 3. Children can spend more of the active time in high intensity activities than adults Figure 4 , as it takes less energy to move the smaller body.
In adults, underweight and overweight is often associated with hyperactivity and hypo-activity, respectively. By monitoring body movement in addition to the measurement of TEE with doubly labeled water, it was shown the paradoxical hyperactivity in anorexia nervosa only occurs in subjects with a higher body mass index Bouten et al. The average PAL was not different between a group of women with anorexia nervosa and a control group.
However, when subjects were assigned to low, moderate and high levels of daily physical activity, a u-shaped distribution was found for the women with anorexia while control subjects were normally distributed with respect to different activity levels. The u-shaped distribution in women with anorexia was related to the body mass index of the subjects, with relatively low body mass index values corresponding to low levels of physical activity and high body mass index values corresponding to high levels of physical activity.
Subjects with a relatively low body mass index had low levels of physical activity and spent less time on activities like sports and exercise, and more time on activities like standing, lying, or sitting than subjects with a higher body mass index. This is in accordance with the reduction in physical activity in the course of chronic energy deficiency and human starvation see section 3.
Physical activity decreases as a consequence of malnutrition and declining physical capacity. Overweight and obesity is not associated with a lower PAL. Activity energy expenditure is similar or even higher in heavier subjects. Selecting young adults, age range 18—50 year, from our own database as presented in Table 1 , leads to the same conclusion Figure 7. The average PAL is around 1. The average value for subjects with a body mass index of 40 kg.
Physical activity level by body mass index category for subjects aged 18 to 50 year from Table 1. The horizontal broken line denotes the average physical activity level of 1. A study in adolescents from the same school showed AEE was similar for obese and gender matched control subjects Ekelund et al. The fact that AEE is similar and not proportionally higher in subjects with a higher body weight has consequences for body movement.
Indeed body movement, as measured simultaneously with accelerometers, was lower in obese than in normal-weight subjects. Overweight implies less physical activity, that is less body movement, but because of the larger body weight, the decreased movement still results in similar energy expenditure as subjects with a normal bodyweight.
In conclusion, a higher weight implies less body movement as shown by the typical occurrence of high intensity activity bursts in young children before reaching adult weight. Overweight subjects are less physically active than normal-weight subjects despite physical activity-related energy expenditure is not necessarily lower. There are several studies on the effect of overfeeding and underfeeding on physical activity as measured under free-living conditions with doubly labeled water.
The effect of overfeeding on physical activity, calculated by expressing TEE as a multiple of resting energy expenditure is non-significant Westerterp, There does not seem to be an effect of overfeeding on physical activity, when overfeeding is lower than twice maintenance requirement, as observed in studies lasting up to 9 weeks.
Long-term underfeeding clearly affects physical activity as already shown by the Minnesota experiment Keys et al. It was initiated to determine the effects of relief feeding, necessitated by the famine in occupied areas of Europe during World War II. Normal weight men were subjected to weeks of semi-starvation, followed by rehabilitation. The weight maintenance diet of In the 24 weeks of semi-starvation, body weight went down from an average of 69 to 53 kg.
At the end of the week interval, subjects reached a new energy balance as body weight leveled off at the lower value.
Energy expenditure equalled energy intake, i. The largest saving on energy expenditure could be ascribed to a decrease in activity energy expenditure Table 2.
Subjects were not capable of doing anything more than hanging around. More recent underfeeding studies were generally performed in overweight and obese subjects, not reducing body weight as much below normal values as in the Minnesota experiment. Then, underfeeding does not seem to affect PAL though there are indications for a reduction, not persisting in time Westerterp, TABLE 2.
Energy saved by 24 weeks semi-starvation in the Minnesota Experiment Keys et al. There are many comparative studies on the effect underfeeding and the effect of underfeeding in combination with exercise training. The general conclusion is that underfeeding is an effective method to lose weight and that there is little effect of an additional exercise-training program. Another explanation for a non-existent effect on weight loss of the addition of exercise to an energy-restricted diet is derived from a typical study performed in Maastricht Kempen et al.
Obese women were randomly assigned to diet alone or diet and exercise for 8 weeks. The exercise group participated in aerobic and fitness exercises, in three min sessions per week, supervised by a professional trainer. Daily energy expenditure decreased similarly in the diet group and the diet plus exercise group from The PAL was the same for the two groups, before as well as at the end of the intervention.
Exercise training did not induce an increase in AEE as observed in subjects with ad libitum food intake. Subjects compensated for the training activity with a decrease in physical activity during the non-training time. Chronic disease negatively affects physical activity, here illustrated by observations in patients with chronic obstructive pulmonary disease COPD.
COPD is associated with muscle wasting, a decrease in respiratory muscle strength and endurance and impaired physical fitness. Patients with COPD often suffer from weight loss due to an inadequate dietary intake combined with increased energy expenditure. Physical activity, as the main determinant of variation in energy requirement, may play an important role. Interestingly, there is no difference in TEE between COPD patients with normal resting energy expenditure and those with increased resting energy expenditure Baarends et al.
Patients with normal resting energy expenditure appeared to have higher energy expenditure for activities than those patients with COPD who had increased resting energy expenditure.
The PAL was significantly higher in the former group than in the latter group. Physical activity affects the energy need of the COPD patient and determines energy balance. In depleted ambulatory outpatients with COPD, energy balance could be reached with oral nutritional supplements as a function of physical activity. Weight change was negatively associated with the energy requirement for physical activity Figure 8. Patients with a PAL above 1. The disease appears to be an important limitation for an active lifestyle.
Chronic disease reduces physical activity and physical capacity, possibly through a limited energy supply. Body mass change in patients with chronic obstructive pulmonary disease over three months after clinical rehabilitation, plotted as a function of the physical activity level After Goris et al. The interrelation between physical activity and body composition is based on comparisons between subjects and within subjects.
In a between subject design, body composition is compared between subjects with a lower and higher activity level. The question is whether body composition differs between sedentary and physically active individuals. In a within subject design, body composition is compared within subjects before and after an activity intervention. Then, the question is whether body composition changes when one gets less active or more active.
Both analyses are described; starting with a comparison between subjects followed by a description of the effect of changes in activity behavior on body composition within the same individual. The comparison of body composition between subjects with a lower and higher activity level was conducted in a cohort of subjects, included in the compiled data presented in Table 1 Speakman and Westerterp, The analysis showed that at the population level, differences in body composition are generally not related to differences in physical activity.
Increasing age is associated with a lower PAL, higher fat mass and lower fat-free mass. For the same body weight, body composition is different at older ages than at younger ages, i. However, the age-induced reduction of physical activity does not seem to be directly related to the age-induced increase in fat mass and decrease in fat-free mass. At any age, body mass does not systematically differ between a sedentary and a more physically active subject.
Many studies show changes in body composition in response to a change in physical activity through exercise training.
0コメント