The effect of pre-cooling or per-cooling in athletes with a spinal cord injury: a systematic review and meta-analysis

Objectives

For individuals with a spinal cord injury (SCI), thermoregulatory challenges presented by the environment are amplified, increasing the risk of exertional heat illness. Thus, this systematic review and meta-analysis aims to quantify the effects of pre- and per-cooling on core temperature (T_c), skin temperature (T_sk) and thermal sensation in participants with SCI and assess the influence of lesion level on the effects of cooling.

Design

Systematic review with meta-analysis.

Methods

Out of 2107 potential studies, 17 were identified via the inclusion criteria for a total of 145 research participants. A total of 12 studies were included in the primary analysis of T_c; 9 included in the analysis of T_sk; and 9 included in the analysis of thermal perceptions. 15 experimental conditions were included in the secondary analysis of lesion level on the effects of cooling.

Results

Cooling reduced T_c (Hedges' g = 0.44; 95% confidence intervals [CI] 0.16, 0.72; p < 0.001), T_sk (Hedges' g = 1.11; 95% CI 0.56, 1.66; p < 0.002) and thermal sensation (Hedges' g = 0.60; 95% CI 0.27, 0.93; p < 0.001). Subgroup analysis revealed pre-cooling (Hedges' g = 0.92), reduced T_c to a greater extent than per-cooling (Hedges' g = 0.25) (p = 0.020). The effect of lesion level on the effectiveness of cooling on T_c had a moderate, positive association (r = 0.518, p = 0.048).

Conclusion

Pre-cooling may reduce T_c to a greater extent than per-cooling during subsequent exercise. Pre-and per-cooling can attenuate the increase in thermal strain in athletes with an SCI. The beneficial effects of cooling are greater in tetraplegic individuals.