Have you ever wondered if the effects of strength training differ between men and women, and among people of various races? Researchers in the School of Public Health at the University of Maryland sought to determine whether specific groups benefited more from strength training. The findings, printed in Medicine & Science in Sports & Exercise (2008; 40 , 669–76), showed that while African Americans tend to have greater muscle volume, they are not more responsive to the effects of strength training than Caucasians are. The study also found that relative adaptations were similar in men and women.
Participants included 181 sedentary but apparently healthy men and women (54 African Americans and 117 Caucasians; 82 men and 99 women). Researchers used one-repetition maximum (1RM) unilateral knee extension exercise for both legs to determine baseline. Quadriceps-specific and overall body composition, body weight and muscle quality (strength per unit of muscle volume) were also tested. Subjects then performed unilateral training of the knee extensors in the dominant leg three times per week for about 10 weeks. Each participant was required to perform the movement through complete range of motion at varied intensities and repetitions for a total of 5 sets.
By the end of the study, the women showed a small decrease in fat percentage while the men remained stagnant. The women increased their relative 1RM strength by 28%, men by 24%. Caucasians improved their relative knee extensor strength by 29%, while African Americans improved theirs by 26%. The African Americans had “significantly greater body mass and BMI,” as well as muscle volume, at both baseline and study completion; however, there was no significant difference in improvements between the two groups.
“The results support our hypothesis that strength training increases quadriceps muscle volume to a greater absolute extent in men than in women, independently of race,” stated the authors. “However, despite the significantly greater hypertrophic effect in men, strength training induces substantial muscle hypertrophy over a relatively short period of time in both men and women, in both Caucasians and African Americans.” Quadriceps-specific and overall body composition showed insignificant change.