African-American men could improve their vascular health by lifting weights, researchers say.
Bo Fernhall (University of Illinois at Chicago, USA) and team found that levels of circulating matrix metalloprotease (MMP) -9, which plays a role in remodeling blood vessels after injury or infection, and 8-isoprostane (8-IsoP), a marker of oxidative stress, were markedly reduced in African-American men after 6 weeks of resistance training.
Although previous studies have shown that aerobic exercise reduces oxidative stress and levels of isoprostane, until now "nobody had a clue about resistance training," commented Marc Cook (University of Illinois at Urbana-Champaign, USA) in a press statement.
He said he now knows what to tell African-American men when they ask him why they should exercise. "If you don't like cardiovascular exercise, if you don't like running on a treadmill, if you can't play basketball or you're not good at it, you can lift weights and improve your health, especially when it comes to high blood pressure," he explained.
"If you just want to lift weights and you do it on a regular basis, you could improve your function."
The study involved 14 African-American and 18 Caucasian men aged 18-35 years matched for body mass index, who participated in three 60-minute sessions of resistance training each week for 6 weeks. The training protocol used was a two-way body part split - legs, back, and biceps on one day; chest, shoulders, and triceps on a separate day.
At baseline, there were no significant differences in circulating levels of MMP-2 or 8-IsoP between the groups. However, MMP-9 was significantly lower in African-American men before training and then significantly decreased after the intervention, whereas there was no change in Caucasian men.
As reported in the Journal of Human Hypertension, resistance training did not significantly modify MMP-2 in either group. However, it did significantly reduce 8-IsoP in African-American men but not in Caucasian men.
The researchers also found that each 1-repetition maximum (1-RM) increase in strength, defined as the maximum amount of weight lifted for a single repetition, significantly correlated with the change in MMP-9 levels after the training intervention.
"It may be that MMP-9 has a different effect on the vasculature of African-Americans than it does on Caucasians," suggested Cook of the findings.
Licensed from medwireNews with permission from Springer Healthcare Ltd. ©Springer Healthcare Ltd. All rights reserved. Neither of these parties endorse or recommend any commercial products, services, or equipment.