Physiological demands of competitive basketball

Energetics of Shuttle Runs: The Effects of Distance and Change of Direction

Shuttle runs can be used to study the physiological responses in sports (such as basketball) characterized by sprints (accelerations/decelerations) and changes of direction.

Purpose:

To determine the energy cost (C) of shuttle runs with different turning angles and over different distances (with different acceleration/deceleration patterns).

Methods:

Nine basketball players were asked to complete 6 intermittent tests over different distances (5, 10, 25 m) and with different changes of direction (180° at 5 and 25 m; 0°, 45°, 90°, and 180° at 10 m) at maximal speed (v ≍ 4.5 m/s), each composed by 10 shuttle runs of 10-s duration and 30-s recovery; during these runs oxygen uptake (VO2), blood lactate (Lab), and C were determined.

Results:

For a given shuttle distance (10 m) no major differences where observed in VO2 (~33 mL · min−1 · kg−1), Lab (~3.75 mM), and C (~21.2 J · m−1 · kg−1) when the shuttle runs were performed with different turning angles. For a given turning angle (180°), VO2 and Lab were found to increase with the distance covered (VO2 from 26 to 35 mL · min−1 · kg−1; Lab from 0.7 to 7.6 mM) while C was found to decrease with it (from 29.9 to 10.6 J · m−1 · kg−1); the relationship between C and d (m) is well described by C = 92.99 × d0.656, R2 = .971.

Conclusions:

The metabolic demands of shuttle tests run at maximal speeds can be estimated based on the running distance, while the turning angle plays a minor role in determining C.

Anaerobic and aerobic performances in elite basketball players

The purpose of this study was to propose a specific lactate minimum test for elite basketball players considering the: Running Anaerobic Sprint Test (RAST) as a hyperlactatemia inductor, short distances (specific distance, 20 m) during progressive intensity and mathematical analysis to interpret aerobic and anaerobic variables. The basketball players were assigned to four groups: All positions (n=26), Guard (n= 7), Forward (n=11) and Center (n=8). The hyperlactatemia elevation (RAST) method consisted of 6 maximum sprints over 35 m separated by 10 s of recovery. The progressive phase of the lactate minimum test consisted of 5 stages controlled by an electronic metronome (8.0, 9.0, 10.0, 11.0 and 12.0 km/h) over a 20 m distance. The RAST variables and the lactate values were analyzed using visual and mathematical models. The intensity of the lactate minimum test, determined by a visual method, reduced in relation to polynomial fits (2nd degree) for the Small Forward positions and General groups. The Power and Fatigue Index values, determined by both methods, visual and 3rd degree polynomial, were not significantly different between the groups. In conclusion, the RAST is an excellent hyperlactatemia inductor and the progressive intensity of lactate minimum test using short distances (20 m) can be specifically used to evaluate the aerobic capacity of basketball players. In addition, no differences were observed between the visual and polynomial methods for RAST variables, but lactate minimum intensity was influenced by the method of analysis.

Changes in the lipid profile of elite basketball and soccer players after a match

The lipid profile of elite basketball and soccer athletes was evaluated and compared with that of inactive individuals. Total cholesterol (T-C), low and high density lipoprotein cholesterol (LDL-C and HDL-C), and triglyceride (TG) concentration were measured in the morning and after a soccer or a basketball match. All parameters of lipid profile measured at a fasted and resting state, except HDL-C, were lower in the athletes compared with the controls (p < 0.01). The soccer match resulted in a greater decrease in TG (78.3 ± 6.7 to 70.7 ± 6.3, p < 0.01), T-C (179.3 ± 10.7 to 171.6 ± 9.6, p < 0.01), LDL-C (110.9 ± 8.9 to 103.5 ± 7.5, p < 0.01) compared with the basketball match that resulted only in a decrease in LDL-C (126.8 ± 9.5 to 117.3 ± 9.1, p < 0.01) and an increase in HDL-C that was similar to that observed after the soccer match (9-12%). These findings support the beneficial effects of basketball and soccer on cardiovascular health.

A randomised trial of pre-exercise meal composition on performance and muscle damage in well-trained basketball players

Background

Attenuating muscle damage is important to subsequent sports performance. It is possible that pre-exercise protein intake could influence markers of muscle damage and benefit performance, however, published research provides conflicting results. At present no study has investigated protein and carbohydrate (PRO/CHO) co-ingestion solely pre-exercise, nor prior to basketball-specific exercise.

The purpose of this study was to answer the research question; would pre-exercise protein intake enhance performance or attenuate muscle damage during a basketball simulation test?

Methods

Ten well-trained male basketball players consumed either carbohydrate (1 g · kg⁻¹ body mass) with protein (1 g · kg⁻¹ body mass), or carbohydrate alone (2 g · kg⁻¹ body mass) in a randomised cross- over design, 90 minutes before completing an 87-minute exercise protocol.

Results

The rise in creatine kinase (CK) from baseline to post-exercise was attenuated following PRO/CHO (56 ± 13U · L⁻¹) compared to carbohydrate (100 ± 10 U · L⁻¹), (p = 0.018). Blood glucose was also higher during and post-exercise following PRO/CHO (p < 0.050), as was free throw shooting accuracy in the fourth quarter (p = 0.027). Nausea during (p = 0.007) and post-(p = 0.039) exercise increased following PRO/CHO, as did cortisol post-exercise (p = 0.038).

Conclusions

Results suggest that in well-trained basketball players, pre-exercise PRO/CHO may attenuate the rise in CK, indicative of a decrease in muscle damage during exercise. However, unfamiliarity with the protein amount provided may have increased nausea during exercise, and this may have limited the ability to see an improvement in more performance measures.

Grunting in tennis increases ball velocity but not oxygen cost

Grunting is widely used by professional tennis players, but no research has been done to verify enhanced performance with grunting. Therefore, the purpose of this study was to determine if grunting enhanced ball velocity in groundstrokes and secondly, to determine if grunting increased the physiological cost of hitting (VO2, HR, VE/VO2, and RPE). Participants were 10 members of the men's (n = 5) and women's (n = 5) tennis teams at a Division I university who had just completed their indoor competitive season. Two hitting sessions were used as players repetitively hit forehand and backhand shots while either grunting or not grunting. Each hitting session consisted of five 2-minute periods with a 1-minute break in between each period. Ball velocity was measured with a radar gun. During each hitting session, players wore a portable metabolic measuring unit. HR was monitored using a Polar monitor, and RPE was assessed using Borg's 6-20 scale. Grunting increased ball velocity (kph) 3.8% compared with non-grunting condition (p < 0.034) with the mean ± SD being 83.4 ± 0.6.1 and 80.3 ± 0.8.7, respectively. The physiological responses (VO2, HR, VE/VO2, and RPE) for the 2 hitting conditions were not significantly different for any variable. When averaged across both hitting conditions, HR over the 5-time periods was higher in periods 3-5 than period (p < 0.018) 1, whereas VE/VO2 and RPE were greater in periods 2-5 than period 1 (p = 0.001). RPE significantly increased over time with periods 2-5 being greater than period 1 (p = 0.001). It was concluded that grunting increased ball velocity without increasing VO2 or VE/VO2 or RPE in comparison with not grunting. It may be worthwhile for players and coaches in tennis and other sports to experiment with grunting to determine possible improvement in performance.

The distances covered by basketball referees in a match increase throughout the competition phases, with no change in physiological demand

Background

It is crucial to know the demands on basketball referees, in different match periods (MPs) and phases of competition, for planning referee training and subsequent successful refereeing.

Objective

To measure and evaluate the distance covered by referees in a match by measuring the number of interruptions, percentage of heart rate (%HR), and blood lactate concentration ([lac]) in different phases of competition and in different MPs.

Method

We studied the qualifying (QP), semifinal (SP), and final (FP) phases of a total of 12 matches (four matches in each phase) of the 2009–2010 Brazilian Basketball League. Distance covered, number of match interruptions, and referees’ %HR and [lac] were analyzed. We compared the results between competition phases and between MPs (1st MP, 2nd MP, 3rd MP, and 4th MP).

Results

Regarding the distances covered, we observed significant differences (P < 0.05) in the 1st, 2nd, and 3rd MPs between the FP and the other two phases (SP and QP) throughout the match, between each phase; in the 4th MP, a significant difference was found when comparing the QP and the other two phases. Comparing the periods within each phase, we found that a greater distance was covered in the 4th MP in relation to the 3rd MP during the FP. No significant differences were found among the remaining variables.

Conclusion

The distances covered by referees in a basketball match increase throughout competition phases. This information is essential for planning of training and for the subsequent success of a referee.

Heart-rate responses by playing position during ball drills in basketball

The physiological load experienced during basketball drills is crucial to understand players' adaptation to team-sport training and plan physical-conditioning programs.

PURPOSE

To compare mean heart-rate (HRmean) responses by playing position during 2-a-side (2v2) and 3-a-side (3v3) ball drills in male junior basketball players and explore the relationship between HRmean and repeated-sprint ability (RSA).

METHODS

Thirty- one players volunteered to participate in this study. On separate occasions, they performed 2v2 and 3v3 ball drills and 6 repetitions of shuttle-run sprints of 20 m (10+10 m), departing every 20 s (RSA). Ball drills took place on the full length but only half the width of the court and were three 4-min bouts separated by 1-min rest periods. An analysis of variance (ANOVA) assessed the effect of the number of players on court (2v2 vs 3v3) and playing position (guards vs forwards vs centers) on HRmean, and a Pearson correlation coefficient evaluated the relation between HRmean and RSA.

RESULTS

The main results showed greater HRmean in 2v2 than in 3v3 ball drills (P < .001) in all playing positions (90.7% ± 1.3% vs 87.6% ± 3% of HRpeak in guards, 91.3% ± 2.1% vs 87.5% ± 3.7% of HRpeak for forwards, and 88.2% ± 3.5% vs 82.2% ± 5.6% of HRpeak in centers, respectively, for 2v2 and 3v3). In addition, centers were characterized by lower HRmean than guards and forwards in 3v3 only (P = .018).

CONCLUSIONS

These results suggest that 2v2 drills should be preferred to 3v3 drills for aerobic conditioning, in particular for centers. Finally, RSA does not seem to influence players' acute responses to ball drills.

Position-related differences in cardiorespiratory functional capacity of elite basketball players

The purpose of this study was to examine possible differences in cardio respiratory functional capacity between perimeter and post elite basketball players. The subjects included 42 highly trained basketball players subdivided into groups of perimeter and post players. Point guards, shooting guards and small forwards were involved in the group of perimeter players, while power forwards and centers represented the group of post players. All players performed a standardized exercise test to evaluate maximal oxygen uptake using a cycle ergometer and automated breath-by-breath system VMAX229C. Collected data of power, heart rate, pulmonary ventilation and gas exchange were compared between the groups of perimeter and post players. Significant differences in anthropometric features between the investigated subgroups were observed. Post players were heavier and taller. Therefore, the perimeter players had significantly higher values of VO_2max and relative power. VO_2max was related to relative power. Relations between those variables can be described by linear regression. Given regressions can be used as a source of typical values for male basketball players. The results indicate that the empirical repartition of basketball players into perimeter and post players has not only a morphological but a physiological basis as well.

A comparison of the activity demands of elite and sub-elite Australian men's basketball competition

The purpose of the study was to describe the differences in the activity demands of sub-elite and elite Australian men's basketball competition. Ten elite (age 28.3 ± 4.9 years, mass 97.0 ± 13.9 kg, height 197.4 ± 8.3 cm) and 12 sub-elite (age 26.1 ± 5.3 years, mass 85.9 ± 13.2 kg, height 191.4 ± 7.6 cm) Australian basketball players participated in the study. Player activity was analysed using video-based time-motion analysis across multiple in-season matches. Customized analytical software was used to calculate player activity into frequencies, mean and total durations (s), and mean and total distances (m) for standing/walking, jogging, running, sprinting, low shuffling, high shuffling, and dribbling movements. Only movement frequency was calculated for jumping and upper body activity. Multivariate analysis of variance revealed that elite players performed significantly more total movement changes (P <0.001), and experienced greater activity workloads while jogging (P <0.01) and running (P <0.002). In contrast, sub-elite players performed significantly more standing/walking (P <0.023) and sprinting (P <0.003) activities. These data suggest that elite basketball competition requires a greater intermittent workload and more sustained activity demands, whereas sub-elite competition may involve greater bursts of activity and longer recovery periods. These differences are likely to reflect variations in player skill and fitness, as well as playing structure between playing standards.

Physiological responses to ball-drills in regional level male basketball players

The main aim of this study was to assess the physiological responses of male basketball players during usual basketball ball-drills. Fourteen male basketball players (age 18.9 ± 2.3 years) performed the following full-court (28 × 15 m) basketball ball-drills (3 × 4-min with 3-min passive rest): five-a-side (5v5), three-a-side (3v3) and two-a-side (2v2). A main effect (P < 0.0001) for ball-drills modes was evident for all variables (5v5 < 3v3 < 2v2). Mean [Vdot]O(2) during the 5v5, 3v3 and 2v2 were 39.0 ± 7.2, 42.0 ± 7.5 and 45.0 ± 6.5 ml · kg(-1) · min(-1) (69 ± 11, 74 ± 12 and 79 ± 11% of [Vdot]O(2peak)) respectively (5v5 = 3v3 < 2v2, P < 0.001). Mean blood-lactate concentrations for 5v5, 3v3 and 2v2 were 4.2 ± 1.8, 6.2 ± 2.3 and 7.8 ± 1.2 mmol (l(-1) respectively (5v5 < 3v3 < 2v2, P < 0.01). During the 5v5, 3v3 and 2v2 mean heart-rate (HR) was 84.0 ± 9.2, 88.0 ± 8.4 and 92.0 ± 5.6% of the individual peak respectively (5v5 < 3v3 < 2v2; P < 0.001). No significant differences were found between the regression-line slope (P = 0.86) and intercept (P = 0.45) of the HR-[Vdot]O(2) relationships of the multistage maximal fitness test (r(2) from 0.80 to 0.96, P < 0.001) and ball-drills (r(2) from 0.70 to 0.95, P < 0.001) conditions. Reducing the number of players over the same playing court resulted in increments in physiological demands. The 2v2 condition provided responses in the range of those reported to improve aerobic and anaerobic fitness. The aerobic demands of ball-drills can be accurately assessed using heart-rate monitoring in basketball.

Physiological demands of off-road vehicle riding

INTRODUCTION

The purpose of this study was to characterize the physiological demands of recreational off-road vehicle riding under typical riding conditions using habitual recreational off-road vehicle riders (n = 128).

METHODS

Comparisons of the physical demands of off-road vehicle riding were made between vehicle types (all-terrain vehicle (ATV) and off-road motorcycle (ORM)) to the demands of common recreational activities. Habitual riders (ATV = 56, ORM = 72) performed strength assessments before and after a representative trail ride (48 +/- 24.2 min), and ambulatory oxygen consumption was measured during one lap (24.2 +/- 11.8 min) of the ride.

RESULTS

The mean VO2 requirement (mL x kg(-1) x min(-1)) while riding an off-road vehicle was 12.1 +/- 4.9 for ATV and 21.3 +/- 7.1 for ORM (P = 0.002), which is comparable to the VO2 required of many common recreational activities. Temporal analysis of activity intensity revealed approximately 14% of an ATV ride and 38% of an ORM ride are within the intensity range (940% VO2 reserve) required to achieve changes in aerobic fitness. Riding on a representative course also led to muscular fatigue, particularly in the upper body.

CONCLUSIONS

On the basis of the measured metabolic demands, evidence of muscular strength requirements, and the associated caloric expenditures with off-road vehicle riding, this alternative form of activity conforms to the recommended physical activity guidelines and can be effective for achieving beneficial changes in health and fitness.