Effects of Eight Weeks of Self-Determined Training on Cardiorespiratory Fitness in Recreationally Trained Females

Abstract

Maintaining or increasing cardiorespiratory fitness (CRF) throughout a training season can be challenging for recreationally trained endurance athletes. Even if athletes intend to increase training during a training season, variables such as the total number of minutes they train per week (min·wk-1) and/or the min·wk-1 of moderate to high intensity training (MHIT) they participate in may affect these athletes’ ability to maintain or increase CRF. PURPOSE: The purpose of this study was twofold: 1) to examine changes in CRF over 8 weeks of self-determined training in recreational female endurance athletes who indicated they planned to increase training min·wk-1; and 2) to examine changes in minutes of total training and MHIT per week from self-reported exercise logs from weeks 1 and 8. METHODS: Fourteen recreationally trained female endurance athletes (cyclists (n=4) and runners (n=10)), all of whom had a baseline VO2max ≥ 80th percentile for their age, completed incremental running or cycling trials to exhaustion to determine VO2max, and provided 7 d exercise training logs at weeks 1 and 8. Runners completed incremental trials on a motorized treadmill, cyclists completed trials on an electronically braked cycle ergometer, and expired gases were measured with a metabolic system during all trials. To record training, athletes were instructed on the use of the Borg RPE scale (15-grade scale) to estimate exercise intensity (I), and were asked to record exercise min and I independently for all phases of exercise sessions. MHIT was considered to be any exercise I > an RPE of 13 (Somewhat Hard to Maximal Exertion on the Borg scale). RESULTS: There was no significant change in mean VO2max values in weeks 1 vs. 8 (p=0.062, 46.50 ± 3.68 vs. 45.87 ± 4.21 mL·kg-1·min-1). There was also no significant change in mean total training minutes (p=0.32, 601.8 ± 221.4 vs. 551.9 ± 194.2 min·wk-1) or mean total MHIT minutes (p=0.38, 272.5 ±193.3 vs. 334.5 ± 218.1 min·wk-1) in weeks 1 vs. 8. CONCLUSIONS: On average, CRF was maintained during the 8 weeks of self-determined recreational training. In addition, we found that average total training min and MHIT min did not change for this group in weeks 1 vs. 8, even though these recreational endurance athletes intended to increase their training during this 8-week period.