“Resistance exercise may offer greater benefits from the increases in blood flow to active muscles and could be implemented as companion to an aerobic training regimen,” according to the new study, led by Scott R. Collier.
The researchers compared vascular (blood vessel) responses to two different types of moderate-intensity exercise: a set of eight resistance exercises, three sets of ten repetitions; and 30 minutes of aerobic cycling. Responses measured included blood vessel widening in response to increased blood flow (flow-mediated dilation) and arterial stiffness (versus distensibility). Greater flow-mediated dilation and lower arterial stiffness are key contributors to cardiovascular health.
Vascular responses to the two types of exercise were significantly different. Resistance exercise produced greater increases in blood flow to the limbs-even though it also caused small increases in central arterial stiffness. In contrast, aerobic exercise produced an increase in aterial distensibility-that is decreased arterial stiffness-but without an increase in blood flow.
Resistance exercise also led to a longer-lasting drop in blood pressure after exercise, compared to aerobic exercise. Dr. Collier and colleagues speculate that resistance may produce “compensatory peripheral vascular effects,” which offset the increase in arterial stiffness while keeping blood pressure fairly constant.
Arterial stiffness of central vessels (like the carotid arteries and aorta) has emerged as an important risk factor for cardiovascular disease. Aerobic exercise is widely recommended to reduce cardiovascular risk. Less is known about the cardiovascular health effects of resistance exercise.
The results support previous studies reporting that resistance and aerobic exercise have opposite effects on arterial stiffness, while showing that resistance exercise has unique effects on blood pressure and limb blood flow.
“The present study indicates that an acute bout of resistance exercise shows many favorable cardiovascular benefits and should therefore be considered as part of a daily exercise training program,” Dr. Collier and co-authors conclude.
Especially because of its ability to increase blood flow to active muscles, weight training could be a valuable companion to an aerobic training regimen. “This may be of greatest importance to women, as they can derive important weight-bearing benefits of resistance training to help prevent and/or treat osteoporosis,” Dr. Collier adds.
1. Collier, Scott R., et al. Changes in Arterial Distensibility and Flow-Mediated Dilation After Acute Resistance vs. Aerobic Exercise. Journal of Strength & Conditioning Research. 24(10):2846-2852, October 2010. DOI: 10.1519/JSC.0b013e3181e840e0