Effects of Time-of-Day Training Preference on Resistance-Exercise Performance

Purpose: The purpose of this study was to investigate how time-of-day training preference influences resistance-exercise performance.Methods:Resistance trained males (n= 12) were recruited for this study. In a crossover, counterbalanced design, participants completed two separate bench-press exercise trials at different times of day: (a) morning (AM; 8:00 hr) and (b) evening (PM; 16:00 hr). Participants answered a questionnaire on time-of-day training preference and completed a preferred (PREF) and nonpreferred (NON-PREF) time-of-day trial. For each trial, motivation was measured using a visual analog scale prior to exercise. Participants completed 2 sets x 2 repetitions at 75% 1-RM with maximum explosiveness separated by 5 min of rest. Mean barbell velocity was measured using a linear position transducer. Participants then completed 1 set x repetitions to failure (RTF) at 75% 1-RM. Rate of perceived exertion (RPE) was measured immediately following exercise.Results:Regardless of preference, velocity (p= .025; effect size (ES) = 0.43) was higher during the PM versus AM trial. However, there were no significant differences in velocity (p= .368; ES = 0.37) between PREF and NON-PREF time of day. There were no significant differences for repetitions between PREF and NON-PREF times (p= .902; ES = 0.03). Motivation was higher in the PREF time versus NON-PREF (p= .015; ES = 0.68). Furthermore, RPE was significantly lower during the PREF time of day (p= .048; 0.55).Conclusions:Despite higher barbell velocity collectively at PM times, time-of-training preference did not largely influence resistance-exercise performance, while motivation is higher and RPE is lower during preferred times.

Automated summary

Regardless of training preference, barbell velocity was higher in the evening trial compared to the morning trial. However, training preference did not significantly influence resistance-exercise performance, with higher motivation and lower rate of perceived exertion during preferred training times.