Low-Intensity Resistance Training Improves Flow-Mediated Dilation in Young Hispanic Adults

Area of Science:

• Exercise Physiology
• Cardiovascular Health
• Vascular Function

Background:

• Endothelial dysfunction is a precursor to cardiovascular disease.
• Resistance exercise training (RET) is known to impact vascular function.
• The optimal intensity of RET for improving endothelial function remains debated.

Purpose of the Study:

• To compare the effects of two different resistance exercise training (RET) intensities on brachial artery flow-mediated dilation (FMD) in sedentary young men.
• To investigate whether lower-intensity RET (50% of 1 repetition maximum) is more effective than higher-intensity RET (80% of 1 repetition maximum) in improving FMD.

Main Methods:

• Thirty-four sedentary males were randomized into three groups: control (no exercise), RET at 50% 1RM, and RET at 80% 1RM.
• The RET program consisted of 8 weeks of training, performed twice per week with similar total workloads across groups.
• Flow-mediated dilation (FMD) of the brachial artery was measured using ultrasound before and after the 8-week intervention.

Main Results:

• The RET group at 50% 1RM showed a significant increase in FMD% post-intervention compared to the control group.
• No significant differences in FMD% were observed between the RET50% and RET80% groups.
• No significant differences in FMD% were found between the RET80% group and the control group.

Conclusions:

• Lower-intensity resistance training (50% 1RM) with higher repetitions appears to be more effective in improving short-term endothelial function than higher-intensity RET (80% 1RM) when total training volume is similar.
• These findings support the principle of training specificity for vascular adaptations.
• Further research is warranted to confirm these preliminary findings and explore long-term effects.