The Performance and Physiological Demands of Basketball Competition and Training.

Abstract

The demands and nature of basketball competition involve repeat high intensity efforts within a game, and during multi-game national and international tournaments. These demands require that the fitness and conditioning attributes of basketball players are well developed to negate the limiting aspects of cumulative fatigue. This fatigue may be attributed to several physical, physiological and psychological factors. Muscle soreness and damage combined with neuromuscular fatigue and metabolite accumulation might also limit muscular performance. Energy substrate depletion and central nervous system fatigue are also causative factors that limit skill execution, the intensity of exercise and basketball performance. To date there has been no quantification and description of the combined physical and physiological demands of basketball training and competition, nor the performance outcomes and fatigue associated with tournament style play. The current understanding of aerobic conditioning, with particular reference to the oxygen uptake of basketball players is limited. However the development of heart rate telemetry systems that predict oxygen uptake and energy expenditure provides a practical means of determining the demands of training and competition. Initially, oxygen uptake (VO2) and energy expenditure predictions by the Suunto™ heart rate system were validated against a first principles gas analysis system. Well-trained male (n=10, age 29.8 ± 4.3 y, VO2 65.9 ± 9.7 ml·kg-1·min-1; mean ± SD) and female (n=7, 25.6 ± 3.6 y, 57.0 ± 4.2 ml·kg-1·min-1) runners completed a two stage incremental running test to establish criterion sub-maximal and maximal oxygen uptake values. Metabolic cart values were used as the criterion measure of VO2 and energy expenditure (kJ) and compared with the predicted values from the Suunto™ heart rate monitoring system. The three levels of software analysis for the Suunto™ system were evaluated: basic personal information (BI), BI + measured maximal heart rate (BIhr), and BIhr + measured VO2 (BIhr+v). Comparisons were analysed using linear regression to determine the standard error of the estimate (SEE): eight subjects repeated the trial within seven days to determine reliability (typical error). Although VO2 (~1.5%) and energy expenditure (~3%) estimations were reliable, the Suunto™ system at the basic heart rate-based level of analysis underestimated VO2 and energy expenditure by ~6% and ~13% respectively. However, the estimation can be improved when maximal heart rate and VO2 values are added to the software analysis. The results provide confidence that heart rate monitoring is a useful means of determining the physical demands of basketball training and competition. In study two, a three day tournament was devised to evaluate the fatigue associated with this style of competition, and the effectiveness of recovery strategies on physical performance. Male players (n=29, 19.1 ± 2.1 y, 1.84 ± 0.34 m, 88.5 ± 14.7 kg) were randomly kg-1day (control), n=9), cold water immersion (11°C, 5 x 1 minute (CWI), n=10) and full leg compression garments (18mmHg, ~18 hrs, n=10). Effects of the recovery strategies on pre-post tournament performance tests were expressed as % ± SD of the change score. Changes and differences were standardized for accumulated game time, assessed against the smallest worthwhile change for each test, and reported qualitatively. Accumulated fatigue was evident over the tournament with small - moderate impairments in several performance tests. Sprint and agility performance decreased by 0.7% ± 1.3 and 2.0% ± 1.9 respectively. Vertical jump also decreased substantially after the first day for all treatments, and remained suppressed at post-tournament. The use of cold water immersion was substantially better in maintaining speed with only a 0.5% ± 1.4 reduction in 20 m sprint time after three days, compared with a 3.2% ± 1.6 reduction after wearing compression garments. Cold-water immersion and compression showed similar substantial benefits in maintaining line-drill performance over the tournament, whereas the control treatment elicited a small increase. Sit & reach flexibility decreased for all groups, however cold-water immersion had the smallest reduction in flexibility. The effect of tournament style play induces impairments of up to 3.2% in tests of physical performance; however these impairments can be offset by up to 1.8% with the use of recovery interventions. Additionally, the use of cold-water immersion appears to promote better restoration of these physical performance measures than carbohydrate+stretching routines and compression garments with the accumulation of game time. The decrements in performance measures may be associated with muscle damage and soreness associated with the high eccentric loads experienced during basketball play. In study 3, the time course of muscle damage markers and inflammatory cytokines during tournament play was investigated. The effect of emerging recovery strategies on any post-game increases of these biomarkers was compared with traditional refuelling and stretching routines. Male players (19.1 ± 2.1 y; 1.91 ± 0.09 m; 88 ± 15 kg, mean ± SD) competed in a three day tournament playing one game each day. Players were assigned to one of three recovery treatments: carbohydrate+stretching, (n=9; CON), cold-water immersion at 11°C for 51 min, (n=10; CWI); full-leg compression at 18 mmHg for ~18 h, (n=10; COMP). Players received their treatment after each game on three consecutive days. Venous blood samples were collected pre-tournament and at 10 minutes, 6 h and 24 h after each game and assayed for concentrations of muscle damage markers fatty-acid binding protein (FABP), creatine kinase (CK) and myoglobin (Mb), and the cytokines interleukin-6 (IL-6) and interleukin-10 (IL-10). Inferences were based on log-transformed concentrations. Post-game increases in damage markers were very large for FABP and Mb, and small for CK after all treatments, with small differences between treatments. There were moderate to large post-game increases in IL-6, while increases in IL-10 were moderate for CWI, and large after COMP and CON. Small decreases in IL-6 and IL-10 were observed under CWI compared to COMP and CON, with no difference between treatments over the tournament. There was no substantial benefit from any recovery treatment at post-game, but there were small - moderate differences between CWI and the COMP or CON treatments for the post tournament measures compared to pre tournament. Tournament play elicits moderate elevations in muscle damage markers suggesting disruption of myocyte membranes in well-trained players. The increase in cytokines may be related to an associated inflammatory response, but also to other physiological considerations. However, the cumulative use of cold-water immersion does appear to minimise concentrations of muscle damage markers after repeated competition, and provide and acute analgesic effect. Basketball coaches have expressed concern that court coverage ability of emerging players is decreasing on an annual basis, potentially due to large in-season training and competition loads, or that development programs were not adequately preparing players. To determine gender differences, positional differences, and patterns of change in court coverage assessed by the basketball line-drill test, male (n=93; age 16.8 ± 1.1 y, (mean ± standard deviation) and female (n=95; age 16.5 ± 1.0 y) basketball players undertook 516 line-drill tests over a 5 year period. The line drill test is a repeat effort test of court coverage routinely used in training, and standardised testing. Log-transformed performance times were analysed using a mixed model that included quadratic within-subject fixed effects for time in the season and time in the program. Changes and differences were standardised for interpretation of magnitudes. Mean performance times were ~28.0 s for males and ~30 s for females. The mean pattern of change in performance within a season differed substantially between genders and playing positions: male guards and female centres showed mode