Standardizing moderate- and vigorous-intensity exercise doses by physiological strain: an exploratory randomized cross-over study

Figures

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  Fig. 1. Structure of moderate- and vigorous-intensity exercises and pre- and post-exercise assessments

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  Fig. 2. Exercise responses in moderate-intensity sessions that were prescribed based on absolute (ABS), relative (REL), and thresholds-based (LT) intensity domains. The grey-shaded area presents moderate intensity domain and its limits as suggested by ACSM. (a) VO2max = maximum oxygen uptake; (b) HRmax = maximum heart rate; (c) HRR = heart rate reserve; (d) RPE = rating of perceived exertion. ***p < 0.001, **p < 0.01, *p < 0.05 compared to 5’, #p < 0.05 between prescription method difference in change from 5’

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  Fig. 3. Exercise responses in vigorous-intensity sessions that were prescribed based on absolute (ABS), relative (REL), and thresholds-based (LT) intensity domains. The grey-shaded area presents vigorous intensity domain and its limits as suggested by ACSM. (a) VO2max = maximum oxygen uptake; (b) HRmax = maximum heart rate; (c) HRR = heart rate reserve; (d) RPE = rating of perceived exertion. ***p < 0.001, **p < 0.01, *p < 0.05 compared to 5’, #p < 0.05 between prescription method difference in change from 5’

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  Fig. 4. Individual results and variance of training load metrics. *p < 0.05 according to modified Levene’s test. EPOC = excess post exercise oxygen consumption; LnRMSSD = the natural logarithm of root mean square of successive differences iTRIMP = individualized training impulse; BLa = blood lactate; sRPE = session rating of perceived exertion

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  Fig. 5. The ratio of variances (F-ratio) with 90% confidence intervals (CI) for comparisons between LT and ABS or REL prescriptions. Values above 1.00 indicate greater variance in ABS or REL than LT sessions, while values below 1.00 indicate greater variance in LT than ABS or REL sessions. Dotted line presents the chosen ± 30% limit for equivalent results

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  Fig. 5. Model-based estimated equivalence lines for 40-min moderate (MOD) and 20-min vigorous (VIG) intensity exercises with relative (a) and lactate-threshold-based (b) intensity normalizations. If intensity is below the line, strain is greater in MOD, while above the line the strain is greater in VIG. For LT-based normalization 0 = basal VO2, 1 = VO2 at LT1, 2 = VO2 at LT2, 3 = VO2max. EPOC = excess post-exercise oxygen consumption; LnRMSSD = the natural logarithm of root mean square of successive differences iTRIMP = individualized training impulse; sRPE = session rating of perceived exertion