Resumen de Comparison of Three Popular Exercise Modalities on V[spacing dot above]O2max in Overweight and Obese.
Fredrik Hjulstad Baekkerud, Ingeborg Megard Leinan, Frederic Solberg, Ulrik Wisløff, Trine Karlsen, Øivind Rognmo
AB Introduction: In this prospective randomized trial, we examined the effect of three popular exercise training modalities on maximal oxygen uptake (V[spacing dot above]O2max) in overweight and obese individuals. In addition, we examined possible concomitant adaptations in endurance exercise performance (time to exhaustion (TTE)), citrate synthase (CS) activity, venous and arterial function, blood volume, and calculated stroke volume (SV). Methods: Thirty subjects were recruited (age, 41 +/- 9 yr; weight, 91 +/- 14 kg; height, 173 +/- 8 cm; body mass index, 30 +/- 4 kg[middle dot]m-2) and randomized to either 6 wk of 4 x 4-min high-intensity interval training (4HIIT) at 85%-95% of HRmax, 10 x 1-min HIIT (1HIIT) at V[spacing dot above]O2max load, or 45-min moderate-intensity continuous training (MICT) at 70% of HRmax. V[spacing dot above]O2max, TTE, CS activity, venous and arterial function, as well as blood volume were measured before and after the training period. O2 pulse was calculated and used to estimate SV. Analysis was conducted per protocol. Results: Only 4HIIT increased V[spacing dot above]O2max (P < 0.01) and significantly more compared with 1HIIT (P = 0.04) and MICT (P = 0.03) (4HIIT, 10%; 1HIIT, 3.3%; and MICT, 3.1%). All groups increased TTE (4HIIT, 198%; 1HIIT, 116%; MICT, 52%), with a higher increase after 4HIIT compared with that after MICT (P = 0.02). Calculated SV increased only after 4HIIT (14.4%). Plasma volume and hemoglobin mass increased after 1HIIT only (5.6% and 6.5%); however, no group differences were found. All groups increased CS activity (4HIIT, 35%; 1HIIT, 35%; MICT, 56%), with no group differences. Arterial inflow (15.7%) and venous outflow (22.7%) decreased after MICT, but there were no group differences. Conclusions: 4HIIT was superior to 1HIIT and MICT in improving V[spacing dot above]O2max likely because of an increased SV.
