The Additional Effect of Training Above the Maximal Metabolic Steady State on VO2peak, Wpeak and Time-Trial Performance in Endurance-Trained Athletes: A Systematic Review, Meta-analysis, and Reality Check.

Abstract

To improve sport performance, athletes use training regimens that include exercise below and above the maximal metabolic steady state (MMSS). The objective of this review was to determine the additional effect of training above MMSS on VO_2peak, W_peak and time-trial (TT) performance in endurance-trained athletes. Studies were included in the review if they (i) were published in academic journals, (ii) were in English, (iii) were prospective, (iv) included trained participants, (v) had an intervention group that contained training above and below MMSS, (vi) had a comparator group that only performed training below MMSS, and (vii) reported results for VO_2peak, W_peak, or TT performance. Medline and SPORTDiscus were searched from inception until February 23, 2023. Fourteen studies that ranged from 2 to 12 weeks were included in the review. There were 171 recreational and 128 competitive endurance athletes. The mean age and VO_2peak of participants ranged from 15 to 43 years and 38 to 68 mL·kg^-1·min^-1, respectively. The inclusion of training above MMSS led to a 2.5 mL·kg^-1·min^-1 (95% CI 1.4-3.6; p < 0.01; I² = 0%) greater improvement in VO_2peak. A minimum of 81 participants per group would be required to obtain sufficient power to determine a significant effect (SMD 0.44) for VO_2peak. No intensity-specific effect was observed for W_peak or TT performance, in part due to a smaller sample size. A single training meso-cycle that includes training above MMSS can improve VO_2peak in endurance-trained athletes more than training only below MMSS. However, we do not have sufficient evidence to conclude that concurrent adaptation occurs for W_peak or TT performance.