Reliability of Cardiorespiratory Parameters During Cycling Exercise Performed at the Severe Domain in Active Individuals

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Cinética do VO2 durante o exercício realizado na potência crítica em ciclistas e indivíduos não-treinados no ciclismo

The objective was to analyze the oxygen uptake (VO2) kinetics during exercise performed at critical power (CP) in subjects with different aerobic status in cycling. Six trained cyclists (GT) and seven non-trained subjects (GNT) underwent to the following protocols in cyclergometer: (a) incremental to exhaustion to determine VO2max and its respective workload (IVO(2)max); b) three square-wave tests to exhaustion at 95-110% IVO2max to determine CP, and; (c) one square-wave test to exhaustion at 100% CP. During the exercise at CP the slow component expressed as absolute value (GT: 342.4 +/- 165.8 ml.min(-1) vs. GNT: 571.3 +/- 170.1 ml.min(-1)) and as the relative contribution to the increase of VO2 during exercise (GT: 10.0 +/- 4.6% vs. GNT: 26.6 +/- 7.3%) were lower for trained subjects. The VO2 at the end of the exercise at PC (GT: 89.8 +/- 8.4% VO(2)max vs. GNT: 97.4 +/- 2.8% VO(2)max) was significantly lower in GT (rho = 0.045), and similar to VO(2)max in GNT. Therefore, the aerobic level might influence the VO2 responses to exercise at PC

Efeito do exercício prévio na determinação da potência crítica

The objective of this study was to analyze the influence of previous exercise on the determination of critical power (CP). Seven apparently healthy nontrained males, of 18 to 25 years, participated of this study. The subjects were submitted, in different days to the following protocols in a cyclergometer: 1) one progressive test until voluntary exhaustion for the determination of lactate threshold (LL), maximal oxygen uptake (VO2max) and its corresponding intensity (IVO2max); 2) six constant workload tests at 95,100 and 110% IVO2max until exhaustion with and without a previous exercise at 70% , in random order. The exhaustion times (tlim) at 95, 100 and 110% IVO2max were adjusted forme thress models of two parameters to estimate CP and anaerobic work capacity (AWC) [P=CTAn/tlim)+CP; tlim = CTAn/(P-PC); P=PC.tlim+ CTAn]. The model with the lowest standard error was considered for the estimation of CP. The tlim at 95% IVO2max was similar without (501 ± 140 s) and with previous exercise (473 ± 99 s). However, the tlim at 100% (381 ± 103 s and 334 ± 101 s) and 110% IVO2max (267 ± 163 s and 227 ± 68 s) was significantly longer with previous exercise. There was no significant difference in CP and AWCat conditions without (200 ± 27 W and 23 ± 11 kJ, respectively) and with previous exercise (212 ± 30 W and 18 ± 8 kJ, respectively). It can be concluded that the parameters of the relationship between power and time were not modified by the previous severe exercise

Influência do exercício prévio pesado na performance aeróbia de curta duração realizada com diferentes estratégias de distribuição da intensidade em indivíduos treinados e não treinados no ciclismo

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)