This study aimed to examine the influence of age and degree of maturity on the comparison and relationship between lactate minimum intensity (LM) and critical speed (CS) throughout childhood and adolescence in swimmers. Forty-six male swimmers aged between 10 and 18 years were divided into three age groups according to pubertal stages and training status. Maximal efforts of 100 and 400 m and the LM protocol with 200 m performances were executed. CS was determined with a 3-distances combination (100, 200, and 400 m). One-way and mixed analysis of variance for repeated measures, Bland-Altman, Pearson correlation, percentage difference, and effect size were used to compare and examine the relationship between variables in each age group. The results revealed that LM and CS had differences in comparison with one another throughout childhood and adolescence in swimmers, because CS clearly underestimated LM in the 10 to 12.6-year age group, while overestimating it in the 15.4 to 18-year age group of swimmers. Thus, coaches and swimmers must be aware of the age-dependency of CS for indices of aerobic endurance measurements in the initial ages of systematized swimming training.
Paulo V. Mezzaroba, Marcelo Papoti and Fabiana A. Machado
Alessandro Moura Zagatto, Jorge Vieira de Mello Leite, Marcelo Papoti and Ralph Beneke
To test the hypotheses that the metabolic profile of table tennis is dominantly aerobic, anaerobic energy is related to the accumulated duration and intensity of rallies, and activity and metabolic profile are interrelated with the individual fitness profile determined via table tennis–specific tests.
Eleven male experienced table tennis players (22 ± 3 y, 77.6 ± 18.9 kg, 177.1 ± 8.1 cm) underwent 2 simulated table tennis matches to analyze aerobic (WOXID) energy, anaerobic glycolytic (WBLC) energy, and phosphocreatine breakdown (WPCr); a table tennis–specific graded exercise test to measure ventilatory threshold and peak oxygen uptake; and an exhaustive supramaximal table tennis effort to determine maximal accumulated deficit of oxygen.
WOXID, WBLC, and WPCr corresponded to 96.5% ± 1.7%, 1.0% ± 0.7%, and 2.5% ± 1.4%, respectively. WOXID was interrelated with rally duration (r = .81) and number of shots per rally (r = .77), whereas match intensity was correlated with WPCr (r = .62) and maximal accumulated oxygen deficit (r = .58).
The metabolic profile of table tennis is predominantly aerobic and interrelated with the individual fitness profile determined via table tennis–specific tests. Table tennis–specific ventilatory threshold determines the average oxygen uptake and overall WOXID, whereas table tennis–specific maximal accumulated oxygen deficit indicates the ability to use and sustain slightly higher blood lactate concentration and WBLC during the match.
Gabriel Motta Pinheiro Brisola, Fabio Milioni, Marcelo Papoti and Alessandro Moura Zagatto
In water polo, several high-intensity efforts are performed, leading to the fatigue process due to accumulation of hydrogen ions, and thus β-alanine supplementation could be an efficient strategy to increase the intramuscular acid buffer.
To investigate whether 4 wk of β-alanine supplementation enhances parameters related to water polo performance.
Twenty-two highly trained male water polo players of national level were randomly assigned to receive 28 d of either β-alanine or a placebo (4.8 g/d of the supplement in the first 10 d and 6.4 g/d in the final 18 d). The participants performed 30-s maximal tethered swimming (30TS), 200-m swimming (P200m), and 30-s crossbar jumps (30CJ) before and after the supplementation period.
The β-alanine group presented significant increases in 30TS for mean force (P = .04; Δ = 30.5% ± 40.4%) and integral of force (P = .05; Δ = 28.0% ± 38.0%), as well as P200m (P = .05; Δ = –2.2% ± 2.6%), while the placebo group did not significantly differ for mean force (P = .13; Δ = 24.1% ± 33.7%), integral of force (P = .12; Δ = 24.3% ± 35.1%), or P200m (P = .10; Δ = –1.6% ± 3.8%). However, there was no significant group effect for any variable, and the magnitude-based-inference analysis showed unclear outcomes between groups (Cohen d ± 95%CL mean force = 0.16 ± 0.83, integral of force = 0.12 ± 0.84, and P200m = 0.05 ± 0.30). For 30CJ the results were similar, with improvements in both groups (placebo, Δ = 14.9% ± 14.1%; β-alanine, Δ = 16.9% ± 18.5%) but with no significant interaction effect between groups and an unclear effect (0.14 ± 0.75).
Four weeks of β-alanine supplementation does not substantially improve performance of 30TS, P200m, or 30CJ in highly trained water polo athletes compared with a control group.
Carlos Augusto Kalva-Filho, Argyris Toubekis, Alessandro Moura Zagatto, Adelino Sanchez Ramos da Silva, João Paulo Loures, Eduardo Zapaterra Campos and Marcelo Papoti
Purpose: To test the reliability and validity of tethered swimming lactate minimum test in young swimmers. Methods: Lactate minimum test was performed twice to test the reliability (experiment 1; n = 13). In addition, the validity was investigated through lactate minimum test relationships with tethered swimming lactate threshold and peak force obtained during graded exercise test (experiment 2; n = 11). Finally, the correlations with mean speeds observed during 200-m (s200m) and 30-minute continuous efforts (s30min) were also analyzed (experiment 3; n = 15). In all experiments, the lactate minimum test began with 3-minute all-out effort to induce lactatemia, followed by an exhaustive graded exercise test. Results: The lactate minimum intensity and mean force during the entire 3-minute all-out effort (MF) showed high reliability (coefficient of variation < 8.9% and intraclass correlation coefficient > .93). The lactate minimum intensity was not different compared with lactate threshold (P = .22), presenting high correlations (r = .92) and agreement (95% limits of agreement = ±7.9 N). The mean force during the entire 3-minute all-out effort was similar to peak force obtained during graded exercise test (P = .41), presenting significant correlations (r = .88) and high indices of agreement (95% limits of agreement = ±11.3 N). In addition, lactate minimum test parameters correlated both with mean speeds observed during 200-m (r > .74) and 30-minute continuous efforts (r > .70). Conclusion: Thus, tethered swimming lactate minimum test can be used for training recommendations and to monitor aerobic adaptations in young swimmers.