Jens Bangsbo

..Furthermore, speed endurance training can maintain muscle oxidative capacity, capillarization, and endurance performance in already trained individuals despite significant reduction in the amount of training...

..This, together with the observation of a higher abundance of the Na(+)-K(+) pump α2 isoform protein in type II fibres, is likely to have importance for the exercise-induced human Na(+)-K(+) pump activity in the different fibre types...

..Thus, football can be used as an activity to elevate the physical capacity of untrained women...

..Adaptations with training do have an effect on the metabolic response to exercise and specific improvement in work capacity...

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..35 ± 0.07 and 0.36 ± 0.07 mmol·kg dry wt(-1)·s(-1) in NOR and HYP). Thus the increase in thigh Vo(2) was not attenuated at the onset of intense knee-extensor exercise despite a reduction in oxygen delivery and pressure...

..The latter finding may be explained by low glycogen levels in individual muscle fibers. Blood lactate is a poor indicator of muscle lactate during soccer match play...

..9 +/- 6.6, 354 +/- 39, and 25.3 +/- 5.9 mmol kg(-1) d.w., respectively. In summary, the PT-test can be used to evaluate a soccer player's technical skills under conditions similar to intense periods of a soccer game...

..0 versus 30.9 +/- 1.5%). In conclusion, the present findings provide evidence that FT fibres are less efficient than ST fibres in vivo at a contraction frequency of 1 Hz, and that the muscle VO2 kinetics is slowed by FT fibre activation...

..Furthermore, performance during intense exercise can be improved and endurance performance maintained even with a reduction in training volume if the intensity of training is very high...

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..The results indicate that an increased Na(+),K(+) pump expression per se is of importance for thigh K(+) reuptake at the onset of low and moderate intensity exercise, but less important during high intensity exercise...

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..0 ± 0.6 mmol/l, respectively). No differences in interstitial Na(+) were observed between CAF and CON. In conclusion, caffeine intake enhances fatigue resistance and reduces muscle interstitial K(+) during intense intermittent exercise...

..We propose that enhanced blood flow and passive stretch are positive physiological stimulators of factors associated with capillary growth in human muscle...

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..To examine the physiological response, reliability, and validity of the Yo-Yo intermittent recovery level 2 test (Yo-Yo IR2)...

..In conclusion, fatigue or impaired performance in soccer occurs during various phases in a game, and different physiological mechanisms appear to operate in different periods of a game...

..These findings suggest that FT fiber recruitment elevates energy requirement of dynamic exercise in humans and support an important role of active FT fibers in producing the slow component of VO2..

..These differences should be taken into account when planning the training and nutritional strategies of top-class players, who require a significant energy intake during a week...

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..The enhanced exercise hyperemia during partial neuromuscular blockade may be related to a greater recruitment of fast-twitch muscle fibers...

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..Am J Physiol 282:R273-R280, 2002), the present data suggest that muscle TCAI accumulate during the initial seconds of exercise; however, this increase is not essential for the contraction-induced increase in mitochondrial respiration...

..In conclusion, activation of additional muscle mass does not result in a higher exercise-induced increase in Na(+)-K(+)-ATPase subunit-specific mRNA...

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..The present study examined the effect of additional speed endurance training (SET) during the season on muscle adaptations and performance of trained soccer players...

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..Additionally, prostanoids and/or nitric oxide appear to play important roles in elevating skeletal muscle blood flow in the initial phase of exercise...

..In conclusion, exercise induces FXYD1 phosphorylation at multiple sites in human skeletal muscle. In mouse muscles, contraction-induced changes in FXYD1 ser68 phosphorylation are fiber-type specific and dependent on PKCα activity...

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..Resting phosphorylation status of the Na(+)-K(+) pump is changed by training and inactivity and may play a role in performance during repeated, intense exercise...

..The Yo-Yo IR tests provide a simple and valid way to obtain important information of an individual's capacity to perform repeated intense exercise and to examine changes in performance...

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..The present study demonstrated a link between interstitial H+ and K+ accumulation, which may be through the ATP-sensitive K+ channels (KATP channels), which are sensitive to changes in H+...

..The high [K+]i levels reached at exhaustion can be expected to cause fatigue, which is supported by the finding that a faster accumulation of interstitial K+, induced by prior arm exercise, was associated with a reduced time to fatigue...

..To examine the activity profile and physical loading of elite female soccer players during match play and to study the relationship between training status and physical match performance...

..Referees performing the most high-intensity work are better to keep up with play. The match activities differ significantly between referees and assistant referees, which should be considered in training and testing procedures...

..Alternatively, mitochondrial efficiency is lowered as exercise progresses, since ATP turnover was unaltered during the ischaemic exercise bout...

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..The present data demonstrate that intense interval training elevates muscle oxygen uptake, blood flow and vascular conductance in the initial phase of exercise at high, but not at low, intensities...

..Additionally, the study suggests that fatigue during intense intermittent short-term exercise was unrelated to muscle CP, lactate, pH, and glycogen...

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..6 min and amounted to 0.24 l min(-1). The present study demonstrates that additional type I and II fibres are recruited with time during intense sub-maximal exercise in temporal association with a significant slow component of VO2...

..The difference in high-intensity running between the 2 levels demonstrates the importance of intense intermittent exercise for match performance in women soccer. Thus, these aspects should be trained intensively in women soccer...

..In conclusion, cellular adaptations to high-intensity exercise training may, in part, be induced by transcriptional regulation. After training, the transcriptional response to an exercise bout at a given workload is diminished...

..In contrast to in vitro conditions, the present study demonstrated that under in vivo conditions the KATP channels are active at rest and contribute to the accumulation of interstitial K+...

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..The data show that ROS are formed within skeletal muscle during exercise and that oral intake of antioxidants can enhance the exercise-induced adaptive mRNA responses of eNOS and UCP3...

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..The type and amount of training should be game related and specific to the technical, tactical, and physical demands imposed on each player...

..e., ∼30 s. Muscle capillaries and the Na(+)-K(+) pump β(1)-subunit seem to be important determinants for performance during exhaustive high-intensity exercises lasting between 30 s and 4 min...

..The present study investigated the fitness and health effects of medium-term soccer training for untrained hypertensive middle-age men...

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..The present findings demonstrate that increasing PDH(a) does not alter muscle O2 uptake and anaerobic ATP provision during the initial phase of intense dynamic knee-extensor exercise in humans...

..However, during intense contraction some Na(+)-K(+) pumps are inactivated and together with further ionic disturbances, likely precipitate muscle fatigue...