Warm-Up Affects Diurnal Variation in Power Output

Abstract

The purpose of this study was to examine whether time of day variations in power output can be accounted for by the diurnal fluctuations existent in body temperature. 8 recreationally trained males (29.8±5.2 yrs; 178.3±5.2 cm; 80.3±6.5 kg) were assessed on 4 occasions following a: (a) control warm-up at 8.00 am; (b) control warm-up at 4.00 pm; (c) extended warm-up at 8.00 am; and, (d) extended warm-up at 4.00 pm. The control warm-up consisted of dynamic exercises and practice jumps. The extended warm-up incorporated a 20 min general warm-up on a stationary bike prior to completion of the control warm-up, resulting in a whole body temperature increase of 0.3±0.2°C. Kinetic and kinematic variables were measured using a linear optical encoder attached to a barbell during 6 loaded counter-movement jumps. Results were 2-6% higher in the afternoon control condition than morning control condition. No substantial performance differences were observed between the extended morning condition and afternoon control condition where body temperatures were similar. Results indicate that diurnal variation in whole body temperature may explain diurnal performance differences in explosive power output and associated variables. It is suggested that warm-up protocols designed to increase body temperature are beneficial in reducing diurnal differences in jump performance.

Caffeine Ingestion Reverses the Circadian Rhythm Effects on Neuromuscular Performance in Highly Resistance-Trained Men

“…This research group found that passive heating somewhat improved morning muscle strength but still it did not reach the neuromuscular performance level found in the afternoon. Likewise, active warm-up, despite raising the morning aural body temperature and increasing muscle force and power output levels, did not increase motor performance to the levels found in the afternoon [4], [16], [17]. These studies suggest that body temperature is one of the most critical components of the circadian rhythm effects on motor performance.…”

Role of biological rhythms in the performance of physical activity

“…Similarly, a warm environment improves diurnal variation in the morning 68) . However, a rise in body temperature due to warming is not always effective in improving diurnal variation [69][70][71][72][73] . In a study in which warming was applied in the morning to increase body temperature to the same level as evening body temperature, did not produce any change in swimming performance 72) .…”

Post-resistance training detraining: time-of-day effects on training and testing outcomes

“…Likewise, oral temperature is time-of-day dependent, with high afternoon values and morning nadirs (Deschenes et al 1998;Hammouda et al 2011Hammouda et al , 2012. This diurnal variation in oral temperature could partially explain time-of-day fluctuations in short-term maximal performance (Martin et al 1999;Taylor et al 2011). However, previous studies showed that these diurnal variations in performance could be modified by the time of day at which specific training was performed (Hill et al 1988(Hill et al , 1989Sedliak et al 2007Sedliak et al , 2008Sedliak et al , 2009.…”