Objectives: To determine the effect of heat acclimatisation (HA) training on blood profile and resting cardiac function in elite athletes with spinal cord injury (SCI). Design: Quasi-experimental. Methods: Eleven athletes (10 m, 1f) with SCI (C5-T3) completed a five-day isothermic HA protocol whereby gastrointestinal temperature (Tc) was elevated to and maintained at ~38.5 degrees Celsius (°C) via intermittent exercise for sixty minutes each day. Blood samples were collected pre- and post-HA to determine changes in plasma volume (PV). Doppler ultrasound of the left-ventricular outflow tract and 2-d speckle tracking echocardiography were performed in a subset of athletes (n = 5) to determine changes in indices of resting left-ventricular function and mechanics, respectively. Results: Ten athletes were successfully able to raise and maintain Tc to 38.5 °C. There was a non-significant increase in PV with HA training (?PV%: 3.0 ± 5.4%, p = 0.086). Following HA, resting HR decreased (63 ± 4 pre-HA vs. 58 ± 5 bpm post-HA, p = 0.020), velocity time integral (21.4 ± 2.7 vs. 23.7 ± 3.0 cm, p = 0.045) and stroke volume increased (64.8 ± 7.6 vs. 70.2 ± 10.5 mL, p = 0.055). Conclusions: Our findings suggest a short-term HA protocol in athletes with SCI is safe and may induce beneficial changes in indices of resting left-ventricular function — however results are highly individualized. Future studies on HA in athletes with SCI should focus on determining mechanisms of adaptation and performance outcomes.
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