Top soccer players do not necessarily have an extraordinary capacity in any of the areas of physical performance. Soccer training is largely based on the game itself, and a common recruitment pattern from player to coach and manager reinforces this tradition. New developments in understanding adaptive processes to the circulatory system and endurance performance as well as nerve and muscle adaptations to training and performance have given rise to more effective training interventions. Endurance interval training using an intensity at 90-95% of maximal heart rate in 3- to 8-minute bouts have proved to be effective in the development of endurance, and for performance improvements in soccer play. Strength training using high loads, few repetitions and maximal mobilisation of force in the concentric mode have proved to be effective in the development of strength and related parameters. The new developments in physical training have important implications for the success of soccer players. The challenge both for coaches and players is to act upon the new developments and change existing training practice.

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Endurance and strength training for soccer players: physiological considerations.

Elite soccer players spend a substantial amount of time trying to improve physical capacities, including aerobic endurance and strength and the strength derivatives of speed and power. The average oxygen uptake for international soccer teams ranges from 55 to 68 ml · kg−1 · min−1 and the half-squat maximal strength from 120 to 180 kg. These values are similar to those found in other team sports. Recently, it has been shown that the heart's stroke volume is the element in the oxygen chain that mainly limits aerobic endurance for athletes. These findings have given rise to more intensive training interventions to secure high stroke volumes, which, in turn, have proved positive in changing both maximal oxygen consumption and soccer performance in terms of distance covered, contacts with the ball and number of sprints in a game. The training employed has consisted of 4 × 4-min “intervals” running uphill at 90 – 95% of maximal heart rate interspersed with 3 min jogging at 70% of maximal heart rate to facilitat...

Training and testing physical capacities for elite soccer players

Aims: Exercise is recommended as prevention, management, and control of all stages of hypertension. There are still controversies about the optimal training dose, frequency, and intensity. We aimed...

Aerobic interval training reduces blood pressure and improves myocardial function in hypertensive patients

Objective : Current guidelines are controversial regarding exercise intensity in cardiovascular prevention and rehabilitation. Although high-intensity training induces larger increases in fitness and maximal oxygen uptake ( V O2max), moderate intensity is often recommended as equally effective. Controlled preclinical studies and randomized clinical trials are required to determine whether regular exercise at moderate versus high intensity is more beneficial. We therefore assessed relative effectiveness of 10-week HIGH versus moderate (MOD) exercise intensity on integrative and cellular functions.

Methods : Sprague–Dawley rats performed treadmill running intervals at either 85%–90% (HIGH) or 65%–70% (MOD) of V O2max 1 h per day, 5 days per week. Weekly V O2max-testing adjusted exercise intensity.

Results : HIGH and MOD increased V O2max by 71% and 28%, respectively. This was paralleled by intensity-dependent cardiomyocyte hypertrophy, 14% and 5% in HIGH and MOD, respectively. Cardiomyocyte function (fractional shortening) increased by 45% and 23%, contraction rate decreased by 43% and 39%, and relaxation rate decreased by 20% and 10%, in HIGH and MOD, respectively. Ca2+ transient time-courses paralleled contraction/relaxation, whereas Ca2+ sensitivity increased 40% and 30% in HIGH and MOD, respectively. Carotid artery endothelial function improved similarly with both intensities. EC50 for acetylcholine-induced relaxation decreased 4.3-fold in HIGH ( p <0.05) and 2.8-fold in MOD ( p <0.20) as compared to sedentary; difference HIGH versus MOD 1.5-fold ( p =0.72). Multiple regression identified rate of systolic Ca2+ increase and diastolic myocyte relengthening as main variables associated with V O2max. Cell hypertrophy, contractility and vasorelaxation also correlated significantly with V O2max.

Conclusions : The present study demonstrates that cardiovascular adaptations to training are intensity-dependent. A close correlation between V O2max, cardiomyocyte dimensions and contractile capacity suggests significantly higher benefit with high intensity, whereas endothelial function appears equivalent at moderate levels. Thus, exercise intensity emerges as an important variable in future preclinical and clinical investigations.

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Moderate vs. high exercise intensity: differential effects on aerobic fitness, cardiomyocyte contractility, and endothelial function.

The present review addresses mechanisms of importance for hyperthermia-induced fatigue during short intense activities and prolonged exercise in the heat. Inferior performance during physical activities with intensities that elicit maximal oxygen uptake is to a large extent related to perturbation of the cardiovascular function, which eventually reduces arterial oxygen delivery to the exercising muscles. Accordingly, aerobic energy turnover is impaired and anaerobic metabolism provokes peripheral fatigue. In contrast, metabolic disturbances of muscle homeostasis are less important during prolonged exercise in the heat, because increased oxygen extraction compensates for the reduction in systemic blood flow. The decrease in endurance seems to involve changes in the function of the central nervous system (CNS) that lead to fatigue. The CNS fatigue appears to be influenced by neurotransmitter activity of the dopaminergic system, but may primarily relate to inhibitory signals from the hypothalamus arising secondary to an increase in brain temperature. Fatigue is an integrated phenomenon, and psychological factors, including the anticipation of fatigue, should not be neglected and the interaction between central and peripheral physiological factors also needs to be considered.

Hyperthermia and fatigue

Left ventricular function was examined during incremental work rates to maximum using simultaneous determinations of stroke volume, left ventricular ejection time (LVET), and diastolic filling time (DT). Seven endurance trained and seven untrained young adult males were studied on a cycle ergometer at matched heart rates of 90, 120, 140, 160, 180, and 190 bpm (+/- 1 bpm). Stroke volume of the untrained subjects reached a plateau at 120 bpm, but stroke volume of the trained subjects continued to increase to their maximum heart rate with no plateau. Throughout incremental work rates, LVET was significantly longer and DT was significantly shorter in the trained subjects. At a heart rate of 190 bpm, the corresponding rates of ventricular emptying and ventricular filling of the trained versus the untrained subjects were 20% and 71% greater, respectively (P < 0.01). We conclude that during incremental work rates the stroke volume of endurance trained athletes increases progressively to maximum with no plateau. In addition, although trained athletes rely on enhancements in both ventricular filling and ventricular emptying to augment stroke volume, by far their major advantage over untrained subjects is in ventricular filling.

Endurance athletes' stroke volume does not plateau: major advantage is diastolic function.

The primary purpose of this study was to determine the fitness variables with the highest capability for predicting hockey playing potential at the elite level as determined by entry draft selection order. We also examined the differences associated with the predictive abilities of the test components among playing positions. The secondary purpose of this study was to update the physiological profile of contemporary hockey players including positional differences. Fitness test results conducted by our laboratory at the National Hockey League Entry Draft combine were compared with draft selection order on a total of 853 players. Regression models revealed peak anaerobic power output to be important for higher draft round selection in all positions; however, the degree of importance of this measurement varied with playing position. The body index, which is a composite score of height, lean mass, and muscular development, was similarly important in all models, with differing influence by position. Removal of the goalies' data increased predictive capacity, suggesting that talent identification using physical fitness testing of this sort may be more appropriate for skating players. Standing long jump was identified as a significant predictor variable for forwards and defense and could be a useful surrogate for assessing overall hockey potential. Significant differences exist between the physiological profiles of current players based on playing position. There are also positional differences in the relative importance of anthropometric and fitness measures of off-ice hockey tests in relation to draft order. Physical fitness measures and anthropometric data are valuable in helping predict hockey playing potential. Emphasis on anthropometry should be used when comparing elite-level forwards, whereas peak anaerobic power and fatigue rate are more useful for differentiating between defense.

Relationship of physical fitness test results and hockey playing potential in elite-level ice hockey players.

Experimental evidence that mutated-self peptides derived from mitochondrial DNA somatic mutations have the potential to trigger autoimmunity

A number of cycle ergometers are presently being used in a variety of laboratory applications for which the quantification of power output is required. To calculate the power output of cycle ergometers with varying sized flywheels, the circumference of the resistance track on the flywheel is multiplied by the number of flywheel revolutions produced with one complete revolution of the pedal. This provides the "effective distance travelled," and by selecting an appropriate combination of pedalling rate plus flywheel resistance, any desired power output can be produced.

Determining power outputs for cycle ergometers with different sized flywheels.

Dr. Roy Shephard is a world-renowned authority on physical activity and health who has brought tremendous honour and distinction to Canada. Roy is undoubtedly a giant in the field of exercise physiology, not just in Canada, but throughout the world. His accomplishments have had an incredible impact around the world on physical activity and health knowledge and upon public policy relating to physical activity and health. Dr. Shephard is truly one of Canada

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Roni Jamnik

Papers

Endurance athletes' stroke volume does not plateau: major advantage is diastolic function.

Relationship of physical fitness test results and hockey playing potential in elite-level ice hockey players.

Experimental evidence that mutated-self peptides derived from mitochondrial DNA somatic mutations have the potential to trigger autoimmunity

Determining power outputs for cycle ergometers with different sized flywheels.

Acknowledging the Immense Contribution of Dr. Roy Shephard in Promoting the Health Benefits of Physical Activity