Factors affecting performance during an endurance relay.

The maximal aerobic performance (V02 max) and energy costs of cycling at various power outputs and equivalent road speeds of a highly trained endurance cyclist (age 23.4 yrs, height 1.95 m, weight 73.1 kg), were measured in the laboratory on an eddy-current cycle ergometer, and the physiological responses related to determinations made during a 24 h cycling time trial event, using continuous ECG recording from which estimates of ergogenic demands were obtained.The cyclist covered a distance of 694 km during the event at an average speed of 28.9 km.hW1 which corresponded to an equivalent oxygen cost of 38.5 ml.kgd1 min' and represented approximately 55% of his V02 max. During the event, the cyclist expended an estimated 82,680 kJ of energy, of which approximately 44,278 kJ (54%) were supplied by repeated feedings of liquids, solids and semi-solids and some 38,402 kJ (46%) came from the stored energy reserves which resulted in a 1.19 kg loss of body weight during the event. The energy demands of the activity were more than three times greater than the highest recorded values of severe industrial work, and similar to the hourly rates of expenditure of shorter duration competitive events, but above the highest values reported over other extreme endurance events over the same period of time. The results thus represent near maximal levels of sustainable ergogenic effort by man over a complete 24 h cycle.

Section: Introductionmentioning

confidence: 99%

Ergogenic demands of a 24 hour cycling event.

White¹,

Ward²,

Nelson³

1984

“…It is unlikely that work can be sustained at a high intensity over this period. Lloyd et al (1977) reported proteinuria in athletes attempting a 24 h relay run world record. With work intensity reduced to a constant oxygen uptake demand of 15 ml/kg/min'1 Thomas and Reilly (1975) reported that exercise can be continued for up to 100 h under conditions of controlled energy intake.…”

Section: Introductionmentioning

confidence: 99%

Physiological, psychological and performance measures during an endurance record for five-a-side soccer

Reilly¹,

Walsh²

1981

Observations were made every 4 h on 2 teams during 91 h 45 min of 5-a-side soccer to investigate stresses on players. Variables monitored were subjective fatigue, state anxiety, grip strength, heart rate, activity, urine protein concentration and liquid intake. Circadian functions were identified in all variables except protein urine as well as significant intercorrelations. Periodicities were consistent with arousal theory with troughs at about 0500-0600 h and crests at 1800 h to 2100 h. Group mean anxiety values increased between days as play was prolonged whilst significant decrements were found in activity, exercise heart rate and urine protein. Mean heart rate for the duration of play was 98 (± S.D. = 10) beats mind and the work severity was considered light. Behavioural abnormalities as found by other investigators in chronically sleep deprived subjects were common during the final two nights.

Metabolic and renal changes in two athletes during a world 24 hour relay record performance.

Irving

Noakes²,

Smit³

1989

Metabolic parameters and renal function were studied in two subjects before, during and after they established a world two-man 24 hour relay record. During the race, the athletes expended an estimated 37.747 We conclude that, although C-reactive protein concentrations increased sooner and were higher than other shorter events and although creatinine, urine excretion and urine osmolality decreased markedly, the intermittent nature of the event, the mild environmental conditions, the moderate percentage of VO2max maintained by the well conditioned subjects and a high fluid intake enabled a rapid return to normality and indeed to enhanced renal tubular function. The only moderate increases in body temperature would be due to the same factors.