Effects of Target Heart Rate Attainment Method on Metabolic, Perceptual, and Performance Responses During Heart Rate-Clamp Exercise in Recreationally Active Female Subjects

Mitchinson, CJ, Benitez, B, Kwak, M, Snell, E, Kuhn, AN, and Bergstrom, HC. Effects of target heart rate attainment method on metabolic, perceptual, and performance responses during heart rate-clamp exercise in recreationally active female subjects. J Strength Cond Res XX(X): 000–000, 2026—This study used a test-retest design to examine ramp and immediate protocols for attaining a target heart rate (HR) and the subsequent effects on metabolic, respiratory, perceptual, and performance responses during HR-clamp cycle ergometry. Fifteen recreationally active female subjects (22 ± 5 years) completed a graded exercise test to determine maximal oxygen consumption (V̇O 2 max) and maximal HR (HRmax), followed by 4 randomized, 20-minute HR-clamp trials at 86% HRmax using either a ramp (gradual increases in power output [PO]) or immediate (instantaneous application of target PO) protocol, each performed twice. Oxygen consumption (V̇O 2 ), minute ventilation (V̇ E ), respiration rate (RR), rating of perceived exertion (RPE), PO, and time to target HR were assessed at HR attainment and averaged across the HR-clamp trials. Analyses included linear mixed models fitted with fixed effects and random intercepts, and one-way repeated measures ANOVAs with intraclass correlation coefficients to examine test-retest reliability ( p < 0.05). Time to target HR did not differ between protocols ( p = 0.958). However, the ramp protocol elicited a greater V̇O 2 , RR, V̇ E , and PO at HR attainment ( p < 0.001–0.035) and a greater V̇O 2 and PO across the HR-clamp trials ( p = 0.008–0.017) compared with the immediate protocol, whereas RPE did not differ between protocols ( p = 0.118–0.984). The ramp protocol demonstrated greater systematic error for metabolic and performance measures, whereas the immediate protocol showed less systematic error and comparable reliability. These findings indicated that the method used to attain a target HR significantly alters the physiological stimulus of HR-clamp exercise, and practitioners and researchers should carefully consider protocol selection when prescribing or interpreting HR-clamp exercise.