Journal Articles

This section lists a number of journal article references and abstracts of research carried out in the area of sport, exercise and particularly cycling physiology, psychology and biomechanics. It is from this knowledge base and years of experience that ensure we provide a quality sport, exercise and coaching science support package. Full references can be obtained from http://www.ingentaconnect.com, http://jap.physiology.org, http://bjsm.bmjjournals.com,

Nielens, H. and Lejeune, T. (2004) Bicycle Shock Absorption Systems and Energy Expended by the Cyclist. Sports Medicine, 34 (2), 71-80.

Abstract

Bicycle suspension systems have been designed to improve bicycle comfort Abstract and handling by dissipating terrain-induced energy. However, they may also dissipate the cyclist’s energy through small oscillatory movements, often termed ‘bobbing’, that are generated by the pedalling movements. This phenomenon is a major concern for competitive cyclists engaged in events where most of the time is spent climbing, e.g. off-road cross-country races. An acceptable method to assess the overall efficacy of suspension systems would be to evaluate energy consumed by cyclists using different types of suspension systems. It could be assumed that any system that reduces metabolic expenditure for the cyclist would automatically lead to performance improvement. Unfortunately, only a limited number of studies have been conducted on that subject. Moreover, the conclusions that can be drawn from most of them are limited due to unsatisfactory statistical power, experimental protocols, measuring techniques and equipment. This review presents and discusses the most relevant results of studies that focused on mechanical simulations as well as on energy expenditure in relation to off-road bicycle suspension systems. Evidence in the literature suggests that cyclist-generated power that is dissipated by suspensions is minimal and probably negligible on most terrains. However, the scarce studies on the topic as well as the limitations in the conclusions that can be drawn from most of them indicate that we should remain cautious before supporting the use of dual suspension bicycles on all course types and for all cyclists. For example, it should be kept in mind that most cross-country racers still use front suspension bicycles. This might be explained by excessive cyclistgenerated power dissipation at the high mechanical powers developed by elite cross-country cyclists that have not been studied in the literature. Finally, suspended bicycles are more comfortable. Moreover, the fact that suspension systems may significantly reduce physical stress should not be overlooked, especially in very long events and for recreational cyclists.

Billat, V. L., Sirvent, P., Py, G., Koralsztein, J.-P. and Mercier, J. (2003) The Concept of Maximal Lactate Steady State A Bridge Between Biochemistry, Physiology and Sport Science. Sports Medicine, 33 (6), 407-426.

Abstract

The maximal lactate steady state (MLSS) is defined as the highest blood lactate Abstract concentration (MLSSc) and work load (MLSSw) that can be maintained over time without a continual blood lactate accumulation. A close relationship between endurance sport performance and MLSSw has been reported and the average velocity over a marathon is just below MLSSw. This work rate delineates the lowto high-intensity exercises at which carbohydrates contribute more than 50% of the total energy need and at which the fuel mix switches (crosses over) from predominantly fat to predominantly carbohydrate. The rate of metabolic adenosine triphosphate (ATP) turnover increases as a direct function of metabolic power 408 Billat et al. Output and the blood lactate at MLSS represents the highest point in the equilibrium between lactate appearance and disappearance both being equal to the lactate turnover. However, MLSSc has been reported to demonstrate a great variability between individuals (from 2–8 mmol/L) in capillary blood and not to be related to MLSSw. The fate of enhanced lactate clearance in trained individuals has been attributed primarily to oxidation in active muscle and gluconeogenesis in liver. The transport of lactate into and out of the cells is facilitated by monocarboxylate transporters (MCTs) which are transmembrane proteins and which are significantly improved by training. Endurance training increases the expression of MCT1 with intervariable effects on MCT4. The relationship between the concentration of the two MCTs and the performance parameters (i.e. the maximal distance run in 20 minutes) in elite athletes has not yet been reported. However, lactate exchange and removal indirectly estimated with velocity constants of the individual blood lactate recovery has been reported to be related to time to exhaustion at maximal oxygen uptake.

Achten, J. and Jeukrup, A. E. (2003) The effect of pre-exercise carbohydrate feedings on the intensity that elicits maximal fat oxidation. Journal of Sports Sciences, 21, 1017-1024.

Abstract

The aim of the present study was to examine the effect of ingesting 75 g of glucose 45 min before the start of a graded exercise test to exhaustion on the determination of the intensity that elicits maximal fat oxidation (Fatmax). Eleven moderately trained individuals (V ÿ O2max: 58.9+1.0 ml _ kg71 _ min71; mean+sx—), who had fasted overnight, performed two graded exercise tests to exhaustion, one 45 min after ingesting a placebo drink and one 45 min after ingesting 75 g of carbohydrate in the form of glucose. The tests started at 95 W and the workload was increased by 35 W every 3 min. Gas exchange measures and heart rate were recorded throughout exercise. Fat oxidation rates were calculated using stoichiometric equations. Blood samples were collected at rest and at the end of each stage of the test. Maximal fat oxidation rates decreased from 0.46+0.06 to 0.33+0.06 g _ min71 when carbohydrate was ingested before the start of exercise (P50.01). There was also a decrease in the intensity which elicited maximal fat oxidation (60.1+1.9% vs 52.0+3.4% V ÿ O2max) after carbohydrate ingestion (P50.05). Maximal power output was higher in the carbohydrate than in the placebo trial (346+12 vs 332+12 W) (P50.05). In conclusion, the ingestion of 75 g of carbohydrate 45 min before the onset of exercise decreased Fatmax by 14%, while the maximal rate of fat oxidation decreased by 28%.

Fukuokaa, Y., Kanekob, Y., Takitac, C., Hirakawa, M. and Harumi KagawaYasuto Nakamuraa, d. (2002) The effects of exercise intensity on thermoregulatory responses to exercise in women. Physiology and Behavior, 76, 567-574.

Abstract

We investigated the influence of altering exercise intensity (150, 300, and 450 kpm/min) on the resetting of the core temperature threshold for the onset of the sweating rate (Mÿ sw) and the alteration of sweating sensitivity during the menstrual cycle in women. Five women underwent cycling exercise for 30 min in both the luteal and follicular phases under controlled neutral environmental conditions (T: 25 _C, RH: 55%). A significantly higher rectal temperature (Tre) was seen in the luteal phase at all exercise intensities, and the same time course of the Tre response with a constant difference of _0.2 _C was shown between the follicular phase and the luteal phase. The Tre threshold for Mÿ sw was also apparently shifted rightward a constant value of 0.2 _C from the follicular phase to the luteal phase, independent of the alteration of exercise intensity. The slope of the Mÿ sw–Tre relationship in the follicular phase did not differ from that in the luteal phase. These results indicate that (1) a rightward shift in the Tre threshold from the follicular phase to the luteal phase can be observed independent of any alteration of the exercise intensity; and (2) the sensitivity of Mÿ sw is also not physiologically influenced by exercise intensity. Thus, alterative thermoregulation during the menstrual cycle was fundamentally unaffected by the change of exercise intensity.

Jonge, X. A. K. J. d. (2003) Effects of the Menstrual Cycle on Exercise Performance. Sports Medicine, 33(11), 833-851.

Abstract

This article reviews the potential effects of the female steroid hormone Abstract fluctuations during the menstrual cycle on exercise performance. The measurement of estrogen and progesterone concentration to verify menstrual cycle phase is a major consideration in this review. However, even when hormone concentrations are measured, the combination of differences in timing of testing, the high inter- and intra-individual variability in estrogen and progesterone concentration, the pulsatile nature of their secretion and their interaction, may easily obscure possible effects of the menstrual cycle on exercise performance. When focusing on studies using hormone verification and electrical stimulation to ensure maximal neural activation, the current literature suggests that fluctuations in female reproductive hormones throughout the menstrual cycle do not affect muscle contractile characteristics. Most research also reports no changes over the menstrual cycle for the many determinants of maximal oxygen consumption ( ÿ VO2max), such as lactate response to exercise, bodyweight, plasma volume, haemoglobin concentration, heart rate and ventilation. Therefore, it is not surprising that the current literature indicates that ÿ VO2max is not affected by the menstrual cycle. These findings suggest that regularly menstruating female athletes, competing in strength-specific sports and intense anaerobic/aerobic sports, do not need to adjust for menstrual cycle phase to maximise performance. For prolonged exercise performance, however, the menstrual cycle may have an effect. Even though most research suggests that oxygen consumption, heart rate and rating of perceived exertion responses to sub-maximal steady-state exercise are not affected by the menstrual cycle, several studies report a higher cardiovascular strain during moderate exercise in the mid-luteal phase. Nevertheless, time to exhaustion at sub-maximal exercise intensities shows no change over the menstrual cycle. The significance of this finding should be questioned due to the low reproducibility of the time to exhaustion test. During prolonged exercise in hot conditions, a decrease in exercise time to exhaustion is shown during the mid-luteal phase, when body temperature is elevated. Thus, the mid-luteal phase has a potential negative effect on prolonged exercise performance through elevated body temperature and potentially increased cardiovascular strain. Practical implications for female endurance athletes may be the adjustment of competition schedules to their menstrual cycle, especially in hot, humid conditions. The small scope of the current research and its methodological limitations warrant further investigation of the effect of the menstrual cycle on prolonged exercise performance.

Francescato, M. P. and Di Prampero, P. E. (2002) Energy expenditure during an ultra-endurance cycling race. Journal of sports medicine and physical fitness, 42(1), 1-7.

Abstract

The energy expenditure of cycling has been investigated in great detail, mainly during trials performed for relatively short periods of time and under well established conditions. The number of investigations performed on long-lasting races, however, is very limited, probably because of practical difficulties. The aim of the present work was an attempt to estimate the energy requirements of 5 amateur cyclists who participated in an ultra-endurance long-lasting road cycling race. A generalized equation obtained from literature was applied to calculate the energy expenditure of 26 to 137 short fractions of the competition. The calculated time weighted net metabolic power output ranged from 6.4.W kg-1 to 10.8 W.kg-1; the corresponding net energy expenditure per unit distance ranging from 73.1.kJ.km-1 to 110.5 kJ.km-1. The total energy expenditure of the competition (rest included) ranged from 44.2 to 186.4 MJ, depending on the total competition duration. For all subjects, the sum total of the overall energy expenditure increased as a power function of cumulated performance time (kJ = 4872.t0.77). However, the daily energy expenditure decreases with increasing the duration of the competition. It is concluded that it is possible to estimate the energy expenditure of ultra-endurance cycling performances, provided that the mechanical power output can be described by well defined equations.

Laursen, P. B. and Rhodes, E. C. (2001) Factors Affecting Performance in an Ultraendurance Triathlon.Sports Medicine, 31(3), 195-209.

Abstract

In the recent past, researchers have found many key physiological variables that correlate highlywith endurance performance. These include maximal oxygen uptake (VO2max), anaerobic threshold (AT), economy ofmotion and the fractional utilisation of oxygen uptake (VO2). However, beyond typical endurance events such as the marathon, termed ‘ultraendurance’ (i.e. >4 hours), performance becomes harder to predict. The ultraendurance triathlon (UET) is a 3-sport event consisting of a 3.8km swim and a 180km cycle, followed by a 42.2km marathon run. It has been hypothesised that these triathletes ride at approximately their ventilatory threshold (Tvent) during the UET cycling phase. However, laboratory assessments of cycling time to exhaustion at a subject’s AT peak at 255 minutes. This suggests that the AT is too great an intensity to be maintained during a UET, and that other factors cause detriments in prolonged performance. Potential defeating factors include the provision of fuels and fluids due to finite gastric emptying rates causing changes in substrate utilisation, aswell as fluid and electrolyte imbalances. Thus, an optimum ultraendurance intensity that may be relative to the AT intensity is needed to establish ultraendurance intensity guidelines. This optimal UET intensity could be referred to as the ultraendurance threshold.

Rehrer, N. J. (2001) Fluid and Electrolyte Balance in Ultra-Endurance Sport.Sports Medicine, 31(10), 701-715.

Abstract

It is well known that fluid and electrolyte balance are critical to optimal exercise performance and, moreover, health maintenance. Most research conducted on extreme sporting endeavour (>3 hours) is based on case studies and studies involving small numbers of individuals. Ultra-endurance sportsmen and women typically do not meet their fluid needs during exercise. However, successful athletes exercising over several consecutive days come close to meeting fluid needs. It is important to try to account for all factors influencing bodyweight changes, in addition to fluid loss, and all sources of water input. Increasing ambient temperature and humidity can increase the rate of sweating by up to approximately 1 L/h.Depending on individual variation, exercise type and particularly intensity, sweat rates can vary from extremely low values to more than 3 L/h. Over-hydration, although not frequently observed, can also present problems, as can inappropriate fluid composition. Over-hydrating or meeting fluid needs during very long-lasting exercise in the heat with low or negligible sodium intake can result in reduced performance and, not infrequently, hyponatraemia. Thus, with large rates of fluid ingestion, even measured just to meet fluid needs, sodium intake is vital and an increased beverage concentration [30 to 50 mmol/L (1.7 to 2.9g NaCl/L) may be beneficial. If insufficient fluids are taken during exercise, sodium is necessary in the recovery period to reduce the urinary output and increase the rate of restoration of fluid balance. Carbohydrate inclusion in a beverage can affect the net rate of water assimilation and is also important to supplement endogenous reserves as a substrate for exercising muscles during ultra-endurance activity. To enhance water absorption, glucose and/or glucose-containing carbohydrates (e.g. sucrose, maltose) at concentrations of 3 to 5% weight/volume are recommended. Carbohydrate concentrations above this may be advantageous in terms of glucose oxidation and maintaining exercise intensity, but will be of no added advantage and, if hyperosmotic, will actually reduce the net rate of water absorption. The rate of fluid loss may exceed the capacity of the gastrointestinal tract to assimilate fluids. Gastric emptying, in particular, may be below the rate of fluid loss, and therefore, individual tolerance may dictate the maximum rate of fluid intake. There is large individual variation in gastric emptying rate and tolerance to larger volumes. Training to drink during exercise is recommended and may enhance tolerance.

Achten, J. and Jeukendrup, A. E. (2003) Heart Rate Monitoring Applications and Limitations.Sports Medicine, 33(7), 517-538.

Abstract

Over the last 20 years, heart rate monitors (HRMs) have become a widely used Abstract training aid for a variety of sports. The development of new HRMs has also evolved rapidly during the last two decades. In addition to heart rate (HR) responses to exercise, research has recently focused more on heart rate variability (HRV). Increased HRV has been associated with lower mortality rate and is affected by both age and sex. During graded exercise, the majority of studies show 518 Achten & Jeukendrup that HRV decreases progressively up to moderate intensities, after which it stabilises. There is abundant evidence from cross-sectional studies that trained individuals have higher HRV than untrained individuals. The results from longitudinal studies are equivocal, with some showing increased HRV after training but an equal number of studies showing no differences. The duration of the training programmes might be one of the factors responsible for the versatility of the results. HRMs are mainly used to determine the exercise intensity of a training session or race. Compared with other indications of exercise intensity, HR is easy to monitor, is relatively cheap and can be used in most situations. In addition, HR and HRV could potentially play a role in the prevention and detection of overtraining. The effects of overreaching on submaximal HR are controversial, with some studies showing decreased rates and others no difference. Maximal HR appears to be decreased in almost all ‘overreaching’ studies. So far, only few studies have investigated HRV changes after a period of intensified training and no firm conclusions can be drawn from these results. The relationship between HR and oxygen uptake ( ÿ VO2) has been used to predict maximal oxygen uptake ( ÿ VO2max). This method relies upon several assumptions and it has been shown that the results can deviate up to 20% from the true value. The HR- ÿ VO2 relationship is also used to estimate energy expenditure during field conditions. There appears to be general consensus that this method provides a satisfactory estimate of energy expenditure on a group level, but is not very accurate for individual estimations. The relationship between HR and other parameters used to predict and monitor an individual’s training status can be influenced by numerous factors. There appears to be a small day-to-day variability in HR and a steady increase during exercise has been observed in most studies. Furthermore, factors such as dehydration and ambient temperature can have a profound effect on the HR- ÿ VO2 relationship.

Atknison, G. and Brunskill, A. (200) Pacing strategies during a cycling time trial with simulated headwinds and tailwinds.Ergonomics, 43(10), 1449-1460.

Abstract

The aims of this study were to examine the effects of one self-selected and two enforced pacing strategies (constant and variable power output) on cycling performance during a time trial in which variable wind conditions were simulated. Seven male cyclists rode their own bicycles on a Computrainer cycle ergometer, which was programmed to simulate a 16.1 km time trial on a flat at course with a 8.05 km h 1 head wind in the first half of the race and a 8.05 km h 1 tailwind in the second half of the race. Subjects rode an initial time trial (ITT) at a self-selected pace to the best of their ability. The mean power output from this trial was then used to calculate the pacing strategies in the subsequent two trials: Constant (C) riders rode the whole time trial at this mean power output; and Variable (V) riders rode the first headwind section at a power output 5% higher than the mean and then reduced the power output in the last 8.05 kmso that the mean power output was the same as in the initial time trial and in trial C. Power output, heart rate and ratings of perceived exertion (RPE) were recorded every 1.61 km. Finish times, 8.05 km split times and blood lactate levels, pre- and post-exercise (to calculate D lactate), were also recorded in each trial. In the ITT, riders chose a mean 6 SD power output of 2676 56 W in the ® rst 1.61 km which was 14% higher than the overall race Mean 6 SD of 2356 41 W. Power outputs then dropped to below the race mean after the first few kilometres. Mean 6 SD finish times in the C and V time trials were 16616 130 and 16596 135 s, respectively. These were significantly faster than the 16716 131 s recorded in the initial time trial (p= 0.009), even though overall mean power outputs were similar (234 ± 235 W) between all trials (p= 0.26).Overall mean RPE and D lactate were lowest in trial V (p <0.05). Perceived exertion showed a pacing strategy by race split interaction (p <0.0001), but it was not increased significantly during the first 8.05 km of the V condition when power outputs were 5% higher than in condition C.Heart rate showed nomain eVect of pacing strategy (p= 0.80) and the interaction between strategy and race split did not reach statistical significance (p= 0.07). These results suggest that in a 16.1 km time trial with equal 8.05 km headwind and tailwind sections, riders habitually set oV too fast in the first few kilometres and will bene® t (10 s improvement) from a constant pacing strategy and, to a slightly greater degree (12 s improvement), from a variable (5% 6 mean) pacing strategy in line with the variations in wind direction during the race. Riders should choose a constant power when external conditions are constant, but when there are hilly or variable wind sections in the race, a variable power strategy should be planned. This strategy would be best monitored with `power-measuring devices’ rather than heart rate or subjective feelings as the sensitivity of these variables to small but meaningful changes in power during a race is low.

Mujika, I. and Padilla, S. (2001) Physiological and Performance Characteristics of Male Professional Road Cyclists.Sports Medicine, 31(7), 479-487.

Abstract

Male professional road cycling competitions last between 1 hour (e.g. the time trial in the World Championships) and 100 hours (e.g. the Tour de France). Although the final overall standings of a race are individual, it is undoubtedly a team sport. Professional road cyclists present with variable anthropometric values, but display impressive aerobic capacities [maximal power output 370 to 570W, maximal oxygen uptake 4.4 to 6.4 L/min and power output at the onset of blood lactate accumulation (OBLA) 300 to 500W]. Because of the variable anthropometric characteristics, ‘specialists’ have evolved within teams whose job is to perform in different terrain and racing conditions. In this respect, power outputs relative to mass exponents of 0.32 and 1 seem to be the best predictors of level ground and uphill cycling ability, respectively. However, time trial specialists have been shown to meet requirements to be top competitors in all terrain (level and uphill) and cycling conditions (individually and in a group). Based on competition heart rate measurements, time trials are raced under steady-state conditions, the shorter time trials being raced at average intensities close toOBLA (˜400 to 420W), with the longer ones close to the individual lactate threshold LT, ˜370 to 390W). Mass-start stages, on the other hand, are raced at low mean intensities (˜210W for the flat stages, ˜270W for the high mountain stages), but are characterised by their intermittent nature, with cyclists spending on average 30 to 100 minutes at, and above LT, and 5 to 20 minutes at, and above OBLA.

Hamilton Lee, David T. Martin, Judith M. Anson, Grundy, D. and Hahn, A. G. (2002) Physiological characteristics of successful mountain bikers and professional road cyclists.Journal of Sports Sciences, 20, 1001-1008.

Abstract

The aims of this study were to compare the physiological and anthropometric characteristics of successful mountain bikers and professional road cyclists and to re-examine the power-to-weight characteristics of internationally competitive mountain bikers. Internationally competitive cyclists (seven mountain bikers and seven road cyclists) completed the following tests: anthropometric measurements, an incremental cycle ergometer test and a 30 min laboratory time-trial. The mountain bikers were lighter (65.3 ± 6.5 vs 74.7 ± 3.8 kg, P = 0.01; mean ± s) and leaner than the road cyclists (sum of seven skinfolds: 33.9 ± 5.7 vs 44.5 ± 10.8 mm, P = 0.04). The mountain bikers produced higher power outputs relative to body mass at maximal exercise (6.3 ± 0.5 vs 5.8 ± 0.3 W´kg-1, P = 0.03), at the lactate threshold (5.2 ± 0.6 vs 4.7 ± 0.3 W´kg-1, P = 0.048) and during the 30 min time-trial (5.5 ± 0.5 vs 4.9 ± 0.3 W´kg-1, P = 0.02). Similarly, peak oxygen uptake relative to body mass was higher in the mountain bikers (78.3 ± 4.4 vs 73.0 ± 3.4 ml ´kg-1 ´min-1, P = 0.03). The results indicate that high power-to-weight characteristics are important for success in mountain biking. The mountain bikers possessed similar anthropometric and physiological characteristics to previously studied road cycling uphill specialists.

Lucía, A., Hoyos, J. and Chicharro, J. L. (2001) Physiology of Professional Road Cycling. Sports Medicine, 31(5), 325-337.

Abstract

Professional road cycling is an extreme endurance sport. Approximately 30 000 to 35 000km are cycled each year in training and competition and some races, such as the Tour de France last 21 days (~100 hours of competition) during which professional cyclists (PC) must cover >3500km. In some phases of such a demanding sport, on the other hand, exercise intensity is surprisingly high, since PC must complete prolonged periods of exercise (i.e. time trials, high mountain ascents) at high percentages (~90%) of maximal oxygen uptake (VO2max) [above the anaerobic threshold (AT)]. Although numerous studies have analysed the physiological responses of elite, amateur level road cyclists during the last 2 decades, their findings might not be directly extrapolated to professional cycling. Several studies have recently shown that PC exhibit some remarkable physiological responses and adaptations such as: an efficient respiratory system (i.e. lack of ‘tachypnoeic shift’ at high exercise intensities); a considerable reliance on fat metabolism even at high power outputs; or several neuromuscular adaptations (i.e. a great resistance to fatigue of slow motor units). This article extensively reviews the different responses and adaptations (cardiopulmonary system, metabolism, neuromuscular factors or endocrine system) to this sport. A special emphasis is placed on the evaluation of performance both in the laboratory (i.e. the controversial Conconi test, distinction between climbing and time trial ability, etc.) and during actual competitions such as the Tour de France.

Kubukeli, Z. N., Noakes, T. D. and Dennis, S. C. (2002) Training Techniques to Improve Endurance Exercise Performances.Sports Medicine, 32(8), 489-509.

Abstract

In previously untrained individuals, endurance training improves peak oxygen uptake (VO2peak), increases capillary density of working muscle, raises blood volume and decreases heart rate during exercise at the same absolute intensity. In contrast, sprint training has a greater effect on muscle glyco(geno)lytic capacity than on muscle mitochondrial content. Sprint training invariably raises the activity of one or more of themuscle glyco(geno)lytic or related enzymes and enhances sarcolemmal lactate transport capacity. Some groups have also reported that sprint training transforms muscle fibre types, but these data are conflicting and not supported by any consistent alteration in sarcoplasmic reticulum Ca2+ATPase activity or muscle physicochemical H+ buffering capacity. While the adaptations to training have been studied extensively in previously sedentary individuals, far less is known about the responses to high-intensity interval training (HIT) in already highly trained athletes. Only one group has systematically studied the reported benefits of HIT before competition. They found that =6 HIT sessions, was sufficient to maximally increase peak work rate (Wpeak) values and simulated 40km time-trial (TT40) speeds of competitive cyclists by 4 to 5% and 3.0 to 3.5%, respectively. Maximum 3.0 to 3.5% improvements in TT40 cycle rides at 75 to 80% of Wpeak after HIT consisting of 4- to 5-minute rides at 80 to 85% of Wpeak supported the idea that athletes should train for competition at exercise intensities specific to their event. The optimum reduction or ‘taper’ in intense training to recover from exhaustive exercise before a competition is poorly understood.Most studies have shown that 20 to 80% single-step reductions in training volume over 1 to 4 weeks have little effect on exercise performance, and that it is more important to maintain training intensity than training volume. Progressive 30 to 75% reductions in pool training volume over 2 to 4 weeks have been shown to improve swimming performances by 2 to 3%. Equally rapid exponential tapers improved 5km running times by up to 6%. We found that a 50% single-step reduction in HIT at 70% ofWpeak produced peak ~6% improvements in simulated 100km time-trial performances after 2 weeks. It is possible that the optimum taper depends on the intensity of the athletes’preceding training and their need to recover from exhaustive exercise to compete.

SiteWizard.co.uk Website Design & eCommerce Software Shopping Cart Solutions