Postexercise oxygen consumption and substrate use after resistance exercise in women

Objective: This study investigated the acute effects of 45 min of resistance exercise (RE) on excess postexercise oxygen consumption (EPOC) and substrate oxidation 120 min after exercise in moderately trained women. Methods: Ten RE trained women (age = 29 ± 3 yr; ht = 168 ± 8.3 cm; wt = 59 ± 5.7 kg; V̇O_2max= 38.3 ± 4.7 mL.kg^-1min^-1) underwent two trials: control sitting and RE. Subjects acted as their own controls in a random counterbalanced design. A 2-d nonexercise period was established between testing trials. Oxygen consumption (V̇O₂) and respiratory exchange ratio (RER) were measured continuously by indirect calorimetry before, during, and after exercise and on a separate control day. RE consisted of 3 sets of 10 exercises at 10-repetition maximum with a 1 min rest period between each set. Fingertip samples of blood lactate concentration [BL] were collected immediately postexercise and every 30 min thereafter until [BL] returned to resting baseline values after exercise. Results: The overall 2-h EPOC was 6.2-L (RE = 33.4 ± 5.1 L vs control = 27.2 ± 0.3 L), corresponding to an 18.6% elevation over the control period. RER was significantly (P < 0.01) below the control RER from minute 30 to minute 120 postexercise (RE = 0.75 ± 0.01 vs control = 0.85 ± 0.01). During the last 30 min of recovery, V̇O₂. and [BL] had returned to control/baseline values and fat oxidation was significantly (P < 0.0001) higher (29.2 vs 16.3 kcal) after RE compared with the control trial. Conclusion: These data indicate that in young RE trained women, acute RE produces a modest increase in V̇O₂ during a 2-h recovery period and an increase in fat oxidation.