NIRS-Derived Muscle Deoxygenation During Arterial Occlusion at Rest Before and After Body Weight Resistance Training...

The aim of this study was to investigate the effects of body weight resistance training with slow movement and tonic force generation on muscle deoxygenation during arterial occlusion at rest. Eleven untrained healthy young male subjects performed Bulgarian split squat training for 3 days per week for 8 weeks. Each training session consisted of 4 sets of 10 repetitions (or until volitional failure). Before and after training, with the subject at rest in supine position, a pneumatic cuff was placed at the proximal site of the thigh and inflated to 250 mmHg to induce the occlusion of arterial blood flow. During arterial occlusion, in the thigh distal to the cuff, muscle O₂ saturation (SmO₂) was continuously monitored at the vastus lateralis (VL) and rectus femoris (RF) muscles using spatially resolved near-infrared spectroscopy. During occlusion, the slope of desaturation and area above the curve (AAC) from baseline values were evaluated. At VL, a significantly shallower desaturation slope was found after training, compared to before. As a result, AAC from baseline was significantly lower after training. In contrast, no significant changes in the desaturation slope or AAC were observed at RF. Body weight resistance training for 8 weeks may cause a shallow desaturation slope during arterial occlusion at rest, though the effects of resistance training on desaturation response during arterial occlusion may be regional in quadriceps muscles.