Supplementation of combined glutathione (GSH) with L-citrulline in response to a single bout of resistance exercise has been shown to increase plasma nitric oxide metabolites, nitrite and nitrate and cyclic guanosine monophosphate (cGMP), which may play a role in muscle protein synthesis. As a result, in response to resistance training (RT) these responses may establish a role for GSH + L-citrulline to increase muscle mass. This study attempted to determine the effects of an 8-week RT program in conjunction with GSH (Setria®) + L-citrulline, L-citrulline-malate, or placebo supplementation on lean mass and its association with muscle strength. The secondary purpose was to assess the safety of such supplementation protocol by assessing clinical chemistry markers. In a randomized, double-blind, placebo-controlled design, 75 resistance-trained males were randomly assigned to ingest GSH + L-citrulline (GSH + CIT), L-citrulline-malate, or cellulose placebo daily while also participating in 8 weeks of RT. The full dose of each supplement was delivered in capsules that were identical in weight, size, shape, and color. Participants completed testing sessions for body composition and muscle strength before and after 4 and 8 weeks of RT and supplementation. Venous blood samples were obtained before and after 8 weeks. Leg press was increased with RT but was not significantly different between groups (p > 0.05); however, bench press strength was not increased with RT (p > 0.05). There were no significant changes in total body mass, fat mass, or total body water during 8 weeks of RT and supplementation. Lean mass increased in both GSH + CIT when compared to PLC; however, the increase was significant only after 4 weeks. Lean mass and strength were positively correlated (p < 0.05) in GSH + CIT, but not CIT-malate or PLC. Neither RT nor supplementation had any significant effects on blood clinical chemistry variables (p > 0.05). Compared to PLC, supplementation of GSH + CIT during resistance training increased lean mass after 4 weeks of RT and was positively associated with muscle strength. However, after 8 weeks of RT there were no significant differences in any of the measured variables.

The aims of this study were to investigate the feasibility of an experiential learning initiative led by minority exercise science undergraduates and to observe the adaptations after a 10-week high-intensity functional training (HIFT) program in 34 underrepresented, hypertensive, and overweight/obese professional firefighters (PFF; age: 36.8 ± 11.0 years, body weight: 97.3 ± 21.5 kg, height: 181.7 ± 6.6 cm; BMI: 29.2 ± 4.9 kg/m²). Data were analyzed for muscular strength and endurance, cardiorespiratory endurance, body composition, agility, flexibility, and readiness for change. The PFFs trained two to three times weekly during their work shifts at vigorous intensity for 40 min. Their resting diastolic blood pressure and resting heart rate significantly decreased. Improvements in agility, muscular strength, and readiness for change were observed. This HIFT experiential learning initiative was feasible and beneficial and improved the PFFs’ health and physical fitness with limited resources. Accredited programs in exercise science participating in low-cost initiatives may aid in mitigating public service workers’ compensation and injury rates to better respond to occupational demands.