Exercise stimulates microvascular perfusion of femoral adipose tissue in older females

Adipose tissue and skeletal muscle are metabolically active tissues that play a central role in whole-body energy homeostasis. The functionality of these tissues, and hence cardiometabolic health, relies on adequate adjustments in perfusion reflecting metabolic demands in different physiological conditions. Acute exercise increases skeletal muscle perfusion, and this response can be enhanced by prolonged exercise training. Yet, whether similar responses occur in adipose tissue remains unclear. Here, we investigated the effect of a single bout of resistance exercise on adipose tissue microvascular perfusion in healthy older females. Moreover, we explored the effects of 8 weeks of aerobic exercise training on the microvascular perfusion response to acute resistance exercise. Study participants (age: 70 ± 4 y; BMI: 24.7 ± 2.8 kg/m²) were assigned to either a supervised aerobic exercise training (3 times/week) or a no training control group. Before and after the intervention period, microvascular blood volume was measured in femoral adipose tissue and the adjacent skeletal muscle using contrast-enhanced ultrasound. More specifically, the measurements were conducted at rest and at t = 10 and t = 40 min after a single resistance exercise session. We found that microvascular blood volume increased in both adipose (3.0 ± 2.5-fold, p < 0.05) and skeletal muscle (4.5 ± 1.9-fold, p = 0.001) tissue after the resistance exercise session. Eight weeks of aerobic exercise training improved adipose tissue microvascular perfusion after acute resistance exercise compared to the control group (time x group, p = 0.033), without significant within-group changes. The present findings indicate that microvascular blood volume in femoral adipose tissue increases after an acute bout of resistance exercise and may be enhanced following exercise training in healthy older females.