College students report sub-optimal perceived wellbeing including fatigue and low energy. The health behaviors of sleep, particularly sleep quality (SQ), sedentary behavior (SED), and physical activity (PA), including both aerobic and resistance training (RT) activity are interrelated and linked to wellbeing. These associations may differ for male and female students as well as students belonging to minority identity groups, such as those identifying as lesbian, gay, bisexual, transgender, or queer (LGBTQ+). The aims of this dissertation were to explore among college students: 1) interrelationships among SQ, SED, RT, aerobic PA, and feelings of energy and fatigue, 2) the impact of sex on the aforementioned interrelationships, and 3) PA behaviors and perceptions of PA among LGBTQ+ -identified students using quantitative and qualitative methods. Aim 1 results (n = 694) determined PA predicted mental and physical energy and fatigue (all p < 0.05) while SQ and SED did not. Additionally, higher levels of RT (p = 0.05) and lower levels of SED (p < 0.01) were associated with improved SQ; however, aerobic PA was not a significant predictor (p = 0.91).Aim 2 determined that among males (n = 149), better SQ significantly predicted higher mental and physical energy and lower physical fatigue whereas among females (n = 544), higher PA levels predicted lower mental and physical fatigue and higher physical energy (all p 0.05) whereas for females (n = 486), lower SED predicted better SQ (p < 0.01). Regarding primary aim 3, less than 30% of our LGBTQ+ participants met current PA guidelines. Qualitative descriptions indicated that in addition general benefits and barriers to PA, these students face added barriers related to their LGBTQ+ status such as General Minority Stress, Perceived Stigma, and Discrimination/Violence. SQ, SED, RT, and PA are important health behaviors associated with the wellbeing of college students; however, the interrelationships may differ for males and females. Further, LGBTQ+ students face additional perceived barriers to PA behaviors which may influence adherence to PA guidelines. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]