Author(s): FRENDA, S., PINTO, G., SCARDINA, A., NAKAMURA, M., KONRAD, A., IOVANE, A., BELLAFIORE, M., BIANCO, A., THOMAS, E., Institution: UNIVERSITY OF PALERMO, Country: ITALY, Abstract-ID: 2115

INTRODUCTION:
Acute resistance training (RT) may transiently impair cardiovascular function. Static stretching (SS) shows positive acute cardiovascular effects, but its role in modulating post-RT recovery remains unclear. This study aimed to determine whether the addition of SS to RT modulates acute endothelial, autonomic, and hemodynamic responses during post-exercise recovery.
METHODS:
Fifteen healthy participants completed a randomized crossover study including RT, RT followed by SS (RT+SS), and a control condition (CC). RT consisted of four sets at 80% one-repetition maximum of bench press and seated biceps curls. In RT+SS, RT was followed by four sets of 30s SS with 30s rest targeting the exercised muscles (pectoral and brachial biceps muscles). Endothelial function was assessed by brachial artery flow-mediated dilation (FMD%) and arterial diameter. Autonomic modulation was evaluated using heart rate variability (SDNN, RMSSD, LF and HF). Hemodynamic responses were assessed using mean arterial pressure (MAP) and heart rate (HR). Data were collected at baseline (BL), post-exercise (POST), and 30 min post-exercise (POST30). Timing of data collection was matched across condition. Time˟condition interaction was analyzed using a 3˟3 repeated-measures analyses of variance.
RESULTS:
For RT, FMD% decreased POST (d=1.84) and returned to BL at POST30 (d=1.11). No reduction in FMD% was observed for RT+SS at any time point.
Arterial diameter increased POST RT (d =1.80) and RT+SS (d=1.53) to the same extent. At POST30, diameter returned to BL only after RT+SS (d=1.49), remaining elevated in RT (d=0.64).
POST RT and RT+ST a similar reduction in time-domain outcomes was observed in RMSSD (d=1.41 and d=1.60) and SDNN (d=1.54 and d=1.57). However, HF decreased POST RT (d=1.14), and the reduction persisted at POST 30 (d= 0.77), while for RT+ST a decrease in HF was observed only at POST (d=1.03). No time˟condition differences were observed for LF.
MAP decreased POST RT (d=0.91) and RT+SS (d=1.37) and returned to BL at POST30, with no differences between conditions. HR increased POST RT (d =2.24) and RT+SS (d =1.73) and persisted at POST30 only after RT (d =0.71). No significant changes were observed in CC at any time point.

CONCLUSION:
RT and RT+ST induced similar post-exercise effects, but distinct patterns emerge during recovery. The addition of SS prevented acute vascular impairment and was associated with improved hemodynamic and autonomic recovery. These findings provide novel insight on the acute physiological effects of combining RT and SS.

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