Muscle-Strengthening Activity Among College Students: Differences By Sex And Associations With Feelings Of Fatigue

PURPOSE: Feelings of low mental energy (ME), physical energy (PE) and feelings of mental fatigue (MF) and physical fatigue (PF) are more prevalent among college females than males. Aerobic physical activity (PA) has been positively related to feelings of energy and negatively related to fatigue. Little is known about the characteristics of muscle-strengthening activity (MSA) among college students, or the associations with feelings of energy and fatigue. In samples of male and female college students, this study aimed to 1) examine characteristics of MSA, and 2) explore associations between MSA and feelings of energy and fatigue. METHODS: Students (n = 648; 79% female; 20.3 ± 1.3 yrs) reported days per week of MSA, muscle groups used, modes, and locations of MSA. ME, MF, PE, and PF were assessed via Mental and Physical State and Trait Energy and Fatigue Scales (scale 0 - 300; more intense feelings = higher scores). Multivariate linear regression assessed associations between days of MSA and ME, MF, PE, PF, controlling for depression, sleep quality, and overall PA. Separate analyses were conducted for males and females. RESULTS: Half of participants reported ≥2 days of MSA with males more likely to meet recommendations than females (66.9% and 48.8%, respectively; p < 0.001). Males participated in more MSA (2.6 ± 1.9 days/wk) and used more muscle groups (5.3 ± 1.5 groups) than females (1.7 ± 1.7 days/wk and 4.3 ± 1.8 groups; all p < 0.001). Males were more likely to use machines (p < 0.001) and free-weights (p = 0.005). Females were more likely to perform Yoga or Tai-Chi (p < 0.001). For males, more days of MSA significantly predicted lower MF (B = -8.5; p = 0.031) and PF (B = -7.2; p = 0.049). For females, MSA did not predict any of the energy and fatigue outcomes (all p > 0.05). CONCLUSIONS: Levels and characteristics of MSA differ between male and female college students. Findings suggest that there may be relationships between MSA and feelings of fatigue, specifically for male students. This important information can be used to develop larger randomized controlled trials among college students to elucidate the potential for causal relationships between MSA and feelings of energy and fatigue. The long-term goal of such research would be to understand whether increasing MSA can improve feelings of fatigue and low energy among college students.