Muscle-Strengthening Activity among College Students: Who, What, Where, and Is It Enough?

ABSTRACT Introduction Muscle-strengthening activity (MSA) is recommended for all major muscle groups ≥2 d·wk −1 . Assessment is often based on the number of days per week of MSA without determining if all major muscle groups are being used, precluding accurate determination of compliance with physical activity (PA) guidelines. Thus, characteristics of MSA remain inadequately characterized, especially among college students. Although it is known that males engage in more MSA than females across the lifespan, more detailed information regarding sex differences in this behavior is needed. The purpose of this study was to comprehensively describe MSA among male and female college students to a) characterize adherence to MSA guidelines according to frequency of MSA and number of muscle groups used, and b) explore sex differences in MSA. Methods College students ( n = 651, 79.1% female, 20.3 ± 1.3 yr old) reported frequency of participation in MSA, muscle groups used, types of MSA performed, and location of MSA engagement via online questionnaires. The proportion of students meeting public health recommendations for MSA and characteristics of MSA participation were analyzed for the total sample and separately for male and female students. Results The proportion of students meeting MSA recommendations ranged from 9.8% to 52.7% depending on the minimum number of muscle groups required. Regardless of criteria, males were more likely to meet PA guidelines and reported more days of MSA, more muscle groups used, more types of MSA, and MSA at more locations than females (all P ≤ 0.05). Conclusions Estimates of compliance with MSA guidelines vary substantially depending upon the number of muscle groups required for compliance. Frequency of MSA and specific muscle groups worked should be included as part of MSA assessment to align with PA guidelines. Sex differences also influence MSA participation; thus, tailoring of messages and programming may improve MSA participation on college campuses.