Effect of seasonal training on selected physical and physiological variables of junior male alpine ski racers

Abstract

The purpose of this study was threefold: 1) to investigate the effect of seasonal training on anthropometry, muscular strength and power, motor ability, flexibility, aerobic power, and anaerobic power and capacity, 2) to investigate the relationship between physical and physiological variables in slalom (SL) and giant slalom (GS) performance, and 3) to establish a regression equation to predict SL and GS performance for junior male Alpine ski racers. A group study research design was employed, which involved pre-season and post-season tests. Measurements of SL and GS performance were taken immediately after each test session. Twenty one junior male Alpine ski racers were assessed for: i) anthropometry following the International Biological program (Weiner and Lourie, 1969) ; ii) muscular strength, power, and endurance of quadricep and hamstring muscle groups using the Dual Channel Cybex II isokinetic unit and a Stoeling hand dynamometer and also using vertical jump, box jump, and hexagonal jump tests; iii) flexibility using the Leighton Flexometer and a sit and reach test; iv) pulmonary function using the autospirometer AS- 700 (Minato Medical Science); v) aerobic power using a cycle ergometer protocol (MacDougall, Wenger, and Green, 1982); vi) anaerobic power and capacity using a cycle ergometer (Bar Or, Dotan, and Inbar, 1977); and vii) anaerobic threshold determined by locating an increase in the ventilatory eguivalent for O2 without an increase in ventilatory equivalent for CO2 and an increase in FEO2 at the peak point of FECO2. Three methods of statistical analyses were used to investigate the results of the study: 1. Paired t-test of pre and post-season results, 2. Pearson Product-Moment correlation for both pre- and post-season results, and 3. Stepwise multiple regression analyses of pre-season SL and GS performance and postseason SL and GS performance. The paired t-test indicated that slalom performance and hip rotation degree significantly (p<.05) improved after the season, and fatigue index for the hamstring muscle group in the left leg showed a significant decline between pre- and post-season tests. The Pearson Product-Moment correlation coefficient revealed several significant (p<.05) relationships between skiing performance (SL & GS) and selected variables as well as several significant intercorrelations between the variables. The stepwise multiple regression analyses revealed that age and hexagonal jump accounted for a large percentage of the variability for both pre-and post-season SL and GS performance. Additional stepwise multiple regression analyses were applied to pre- and post-season SL and GS performance with the independent variable "age" removed to investigate what other predictors would account for the variation in the absence of the age variable. In general, isometric quadricep strength in the right leg accounted for most of the variance in 2 out of the 4 analyses and hexagonal jump accounted for most of the variance in the remaining 2 analyses.