Aerobic power and peak power of elite America’s Cup sailors

Big-boat yacht racing is one of the only able bodied sporting activities where standing armcranking (‘grinding’) is the primary physical activity. However, the physiological capabilities of elite sailors for standing arm-cranking have been largely unreported. The purpose of the study was to assess aerobic parameters, VO2peak and lactate threshold (OBLA), and anaerobic performance, torque- and power-crank velocity relationships and therefore peak power (Pmax) and optimum crank-velocity (ωopt), of America’s Cup sailors during standing arm-cranking. Thirty-three elite professional sailors performed a step test to exhaustion, and a subset of ten grinders performed maximal 7 s isokinetic sprints at different crank velocities, using a standing arm-crank ergometer. VO2peak was 4.7(0.5) L/min (range: 3.6-5.5 L/min) at a power output of 332(44) W (range: 235- 425 W). OBLA occurred at a power output of 202(31) W (61% of Wmax) and VO2 of 3.3(0.4) L/min (71% of VO2peak). The torque-crank velocity relationship was linear for all participants (r=0.9(0.1)). Pmax was 1420(37) W (range: 1192-1617 W), and ωopt was 125(6) rpm. These data are among the highest upper-body anaerobic and aerobic power values reported. The unique nature of these athletes, with their high fat-free mass and specific selection and training for standing arm cranking, likely accounts for the high values. The influence of crank velocity on peak power implies that power production during on-board ‘grinding’ may be optimised through the use of appropriate gear-ratios and the development of efficient gear change mechanisms

Salivary IgA as a risk factor for upper respiratory infections in elite professional athletes

The relationship between physiological and psychological stress and immune function is widely recognized; however, there is little evidence to confirm a direct link between depressed immune function and incidence of illness in athletes. Purpose: To examine the relationship between salivary immunoglobulin A (s-IgA) and upper respiratory infections (URI) in a cohort of professional athletes over a prolonged period. Methods: Thirty-eight elite America’s Cup yacht racing athletes were studied over 50 wk of training. Resting, unstimulated saliva samples were collected weekly (38 h after exercise, consistent time of day, fasted) together with clinically confirmed URI, training load, and perceived fatigue rating. Results: s-IgA was highly variable within (coefficients of variation [CV] = 48%) and between subjects (CV = 71%). No significant correlation was found between absolute s-IgA concentration and the incidence of URI among athletes (r = 0.11). However, a significant (28%, P G 0.005) reduction in s-IgA occurred during the 3 wk before URI episodes and returned to baseline by 2 wk after a URI. When an athlete did not have, or was not recovering from URI, a s-IgA value lower than 40% of their mean healthy s-IgA concentration indicated a one in two chance of contracting an URI within 3 wk. Conclusion: On a group basis, relative s-IgA determined a substantial proportion of the variability in weekly URI incidence. The typical decline in an individual’s relative s-IgA over the 3 wk before a URI appears to precede and contribute to URI risk, with the magnitude of the decrease related to the risk of URI, independent of the absolute s-IgA concentration. These findings have important implications for athletes and coaches in identifying periods of high URI risk

Influence of crank length and crank-axle height on standing arm-crank (grinding) power

To determine the optimal crank length and crank-axle height for maximum power production during standing arm-cranking (‘grinding’). Nine elite professional America’s Cup grinders (age: 36 ± 2 y; body mass: 104 ± 1 kg; body fat 13 ± 2%) performed eight maximal 6 s sprints on an adjustable standing arm-crank ergometer fitted with an SRM powercrank. The protocol included crank lengths of 162, 199, 236 and 273 mm and crank-axle heights of 850, 950, 1050 and 1150 mm. Peak power, ground reaction forces (GRF) and joint angles were determined and compared for different crank lengths and crank-axle heights with repeated-measures ANOVA. Results: Peak power was significantly different between crank lengths (P=0.006), with 162 mm lower than all others (P<0.03). Optimal crank length was 12.3% of arm-span, or 241 ± 9 mm for this cohort of athletes. Peak power was significantly less for the crank-axle height of 850 mm compared to 1150 mm (P=0.01). The optimal crank-axle height for peak power was between 50 and 60% of stature (950-1150 mm in this study). Hip flexion was greater at the lowest crank-axle height (850 mm) than at 1050 and 1150 mm (P<0.01), and the resultant GRF was also reduced compared to all other heights, indicating greater weight bearing by the upper body. Changes in crank length and crank-axle height influence performance during maximal standing arm-crank ergometry. These results, suggest that standard leg-cycle crank lengths are inappropriate for maximal arm-cranking performance. In addition, a crank-axle height of <50% of stature, which is typically used in America’s Cup sailing, may attenuate performance