A high-intensity warm-up increases thermal strain but does not affect repeated sprint performance in athletes with a cervical spinal cord injury

Purpose: To determine if a high-intensity intermittent warm-up (WU) strategy alters thermoregulatory and performance measures in wheelchair rugby (WR) players with and without spinal cord injury. Methods: Seven WR players with spinal cord injury (SCI) and eight without SCI (NON-SCI) completed a WU simulating their current practice (CON) and an intervention WU consisting of greater high-intensity efforts (INT), followed by an intermittent sprint protocol (ISP) designed to simulate the demands of a WR game. Core temperature (Tcore), heart rate and blood lactate concentration were recorded throughout the WU and ISP. Performance variables including peak power and peak speed were compared between conditions. Results: During the WU, Tcore was similar between conditions for SCI and NON-SCI. During the ISP, a greater Tcore was found for SCI compared with NON-SCI (38.2±0.3 vs 37.7±0.3℃: d=0.75), and the SCI group experienced a higher peak Tcore for INT compared with CON (39.1±0.7 vs 38.6±0.6℃; p=0.004). Peak Tcore was reached later in the ISP in SCI compared to NON-SCI (97±4 vs 48±27 min; p<0.0005). No significant differences were found in peak power or peak speed during the ISP between conditions (p≥0.143). Conclusions: The high intensity WU increased thermal strain in the SCI group during the ISP, specifically peak Tcore, whilst not impacting performance. However, for some NON-SCI players, an increase in power output may be observed during the first quarter. To reduce the risk of increased thermal and physiological demand, different WU strategies that are tailored to SCI and NON-SCI are warranted.