Author(s): GOEPP, T., GOEPP, T., GIBSON, O., RUPP, T., HAYES, M., Institution: UNIVERSITÉ SAVOIE MONT BLANC , Country: FRANCE, Abstract-ID: 1018

INTRODUCTION:
This study examined whether heat acclimation (HA), and HA with blood flow restriction (BFR) could attenuate cognition and neuromuscular function impairments in cognitive-motor dual-task (CMDT) during exercise-heat stress.
METHODS:
Twenty trained adults were randomly assigned to one of two HA protocols over six sessions (~8 days). Each session consisted of 4×8-min self-regulated cycling intervals (5-min “strong effort”, 3-min “moderate effort”) in temperate conditions (20°C), immediately followed by 40-min hot water immersion (40°C). One group exercised with BFR applied during the “strong” bouts (50% arterial occlusion pressure; BFRHA), whereas the control group completed without occlusion (CTRLHA). Before and after HA protocols, participants completed an exercise-heat stress test with CMDT (pre- post-HA; 40°C, 40% RH): 1×7-min self-regulated cycling (“strong effort”) followed by 2×7-min fixed-power blocks with a sustained attention task (SART). Heart rate (HR), rectal temperature (Trec), and perceived mental effort were recorded, while neuromuscular function (voluntary activation, peripheral responses) was assessed post-CMDT during a 1-min sustained maximal voluntary contraction.
RESULTS:
During HA sessions, HR and Trec where comparable between groups (P≥0.19), despite a reduced power during BFRHA (-22±6%; P<0.001). Post-HA, both groups reduced peak HR (-6±6 bpm) and Trec (-0.2±0.2°C; P≤0.003). Both improved SART performance (+10±4%, P<0.001) with lower mental effort, while reduced force loss was evident only in BFRHA post-HA (+18±12%, P=0.001), consistent with lower central fatigue (P=0.028) versus pre-HA.
CONCLUSION:
Effective heat adaptations were induced by both HA protocols, despite the lower workload with BFR. Both approaches enhanced sustained attention during an exercise-heat stress with CMDT, while BFR additionally mitigated central fatigue.