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Resistance-type exercise (RE) elicits distinct acute metabolic and hormonal responses, which can be modulated by the manipulation of training variables. The purpose of this study was to compare the metabolic (blood lactate and estimated lactic anaerobic system energy expenditure) and hormonal (growth hormone [GH]) responses to RE sessions composed exclusively of multijoint (MULTI) or single-joint (SINGLE) exercises. Assessments of creatine kinase (CK) levels were also performed. In a crossover design, 10 recreationally resistance-trained men (age: 26.9 ± 3.0 years, total body mass: 83.2 ± 13.8 kg; height: 176 ± 7.0 cm; training experience: 5.5 ± 2.4 years) were randomly submitted to both protocols. Blood collections were made pre, 3 minutes after, and 36 hours after each experimental session. No significant difference between MULTI vs. SINGLE was observed for the rises in blood lactate (p = 0.057) and GH (p = 0.285) levels. For CK, a significant difference between the protocols was noted, in which MULTI resulted in significant rises after 3 minutes (p = 0.017) and 36 hours (p = 0.043) compared with SINGLE. In conclusion, the findings of this study suggest that resistance-trained individuals display similar metabolic and hormonal responses when performing MULTI and SINGLE exercise protocols. Also, RE sessions comprising MULTI exercises induce a higher magnitude of muscle damage, which may require a longer recovery period compared with SINGLE. [ABSTRACT FROM AUTHOR]

This study aimed to test the reproducibility of the 3-min all-out effort applied using shuttle running and compare its values to aerobic parameters. On the first day, 14 futsal players underwent an exhaustive test to determine the maximal incremental speed (MIS) and anaerobic threshold (AnT). On the second day, the participants performed the 3-min all-out effort (n=14), which was repeated after 48 h (third day) to test its reproducibility (n=11). Peak oxygen consumption (V̇ O2PEAK) and peak blood lactate concentrations ([La-]) were determined from 3-min all-out efforts performed through a 20-m shuttle run on the official court. The distance covered, mean speed, and critical speed (CS) during the 3-min all-out presented direct relationships with aerobic parameters determined through the incremental test (r>0.62). The distance covered above CS (D') presented a direct relationship with peak lactate concentrations induced by a 3-min all-out effort (r=0.81). Despite the acceptable levels of reproducibility observed for most of the 3-min all-out variables, the minimal detectable change for D' was high (72%). Our results demonstrated the potential use of mean speed to evaluate aerobic fitness. However, the applicability of the 3-min all-out shuttle run test to monitor training adaptations should be avoided, at least in nonexperienced athletes. [ABSTRACT FROM AUTHOR]

The aim of this study was to establish the validity and reliability and verification of the reproducibility of the lactate minimum test (LM) to predict the maximal lactate steady state exercise intensity (MLSS) on a futsal-spe-cific circuit (Futsal_circuit) which takes into consideration the technical movements performed. 16 male Brazilian futsal players (body mass: 67.7 ±8.3 kg; height: 1.73 ± 0.05 m) were distributed randomly into 2 studies with 8 athletes in each (Study A- reproducibility; Study B -validity). First, aerobic capacity was determined by adapting the protocol of the LM to the futsal_circuit. In study A, the evaluation was repeated after 7 days (test e re-test) and, in study B, the MLSS on the futsal_circuit was performed. LM intensity (test = 7.7 ± 0.3 km.h-1; retest = 7.7 ± 0.4 km.h-1) showed a concordance (CV=4.13 and ET=0.32)on study A. No significant differences, high association (r = 0.80; p<0.05) and concordance (lower limits: - 0.58 km.h-1; Upper limits: 0.55 km.h-1) between LM and MLSS (7.5 ±0.5 km.h-1 LM; 7.5± 0.4 km.h-1 MLSS) on study B. According to the results, we can conclude that the Futsal_circuit is reliable, reproducible and valid for assessing the functional aerobic capacity of futsal players. [ABSTRACT FROM AUTHOR]

The aims of the present study were to verify the contributions of the energy systems during repeated sprints with a short recovery time and the associations of the time- and power-performance of repeated sprints with energetic contributions and aerobic and anaerobic variables. 13 healthy men performed the running-based anaerobic sprint test (RAST) followed by an incremental protocol for lactate minimum intensity determination. During the RAST, the net energy system was estimated using the oxygen consumption and the blood lactate responses. The relative contributions of oxidative phosphorylation, glycolytic, and phosphagen pathways were 38, 34, and 28 %, respectively. The contribution of the oxidative pathway increased significantly during RAST especially from the third sprint, at the same time that power- and time-performances decreases significantly. The phosphagen pathway was associated with power-performance (peak power = 432 ± 107 W, r = 0.65; mean power = 325 ± 80 W, r = 0.65; minimum power =241 ±77 W, r = 0.57; force impulse= 1 846±478N-s, r = 0.74; p<0.05). The time-performance (total time = 37.9 ± 2.5 s; best time = 5.7 ± 0.4 s; mean time = 6.3 ± 0.4 s; worst time = 7.0 ± 0.6 s) was significantly correlated with the oxidative phosphorylation pathway (0.57 < r > 0.65; p < 0.05) and glycolytic pathway (0.57 < r > 0.58; p < 0.05). The oxidative pathway appears to play an important role in better recovery between sprints, and the continued use of the glycolytic metabolic pathway seems to decrease sprint performances. Finally, the phosphagen pathway was linked to power production/maintenance. [ABSTRACT FROM AUTHOR]