Comparison of a Continuous and Discontinuous GXT on VO₂ in Resistance-Trained and Endurance-Trained Males

Traditional graded exercise testing to assess maximal oxygen uptake (VO_2max) may not well represent resistance-trained athletes due to their unfamiliarity with continuous exercise. For this reason, it is possible discontinuous exercise protocols may better represent the maximum capacity for aerobic metabolism in resistance-trained athletes, in order to provide a more valid assessment of VO_2max and risk of developing cardiovascular disease.

The purpose of this experiment was to compare VO_2peak during a continuous and discontinuous modified Bruce protocol in both highly resistance-trained and endurance-trained males.

19 college-aged males (age: 20.6 ± 1.9 yr, height: 176.5 ± 7.6 cm, weight: 85.0 ± 25.6 kg) of intermediate resistance- or endurance-trained status were recruited for this study. Participants completed a continuous and discontinuous modified Bruce protocol on two visits separated by seven days.

A 2×2 one-way ANOVA revealed a significant group main effect for VO_2peak (p = 0.004) in which endurance athletes achieved significantly higher VO_2peak values compared to resistance-trained athletes. A significant group main effect for RPE was found (p = 0.045) in which endurance-trained reported significantly higher RPE values than the resistance-trained. A significant main effect for protocol for heart rate (p = 0.033) was found in which individuals achieved higher heart rates during the continuous protocol compared to the discontinuous.

Although a discontinuous protocol with rest periods between stages is comparable to the exercise mode familiar to resistance-trained athletes, it did not provide any additional benefit to VO_2peak values.