Proceedings of the Sixteenth International Society of Sports Nutrition (ISSN) Conference and Expo

2020 Journal of the International Society of Sports Nutrition  
Suppl 1):A2 Background A large and growing body of research has shown that long-term fasting (>24 h) or sustained intermittent fasting can reduce inflammation and mediate improved cognitive and psychological health. The effects of short-term fasting on these processes are not wellunderstood. In order to begin to address this uncertainty, we investigated the possibility that a short-term (13 hour) fast could increase cognitive processes, and reduce inflammation. Materials and Methods We applied
more » ... Methods We applied a crossover design study, with a baseline and a fasting session occurring one week apart (condition order was counterbalanced). For the fasting session, participants were instructed not to eat for at least 13 hours before the study session. For the baseline session, participants were instructed to eat breakfast. The cognitive test battery included measures of working memory, sustained attention, speed of processing, cognitive inhibition, and mind wandering. Blood and saliva samples were obtained at the end of each session for energy and stress (cortisol) and inflammation (IL-1β and Il-6) biomarker quantification. Height, weight, heart rate, and blood pressure were also recorded. Results Cognition data: Data from 4 participants were removed due to failure to complete one or more cognitive tasks as instructed. No significant difference was observed on the working memory task (Symmetry Span), speed of processing (Pattern comparison), inhibition (Flanker), or sustained attention (SART target accuracy and dprime), all p's > .05. Mind wandering was higher at fasting (M = .60, SD = .28) than at baseline (M = .53, SD = .27), t(29) = 2.27, p = .031, d = 0.25. False alarms on the sustained attention task were higher during fasting (M = 16.54, SD = 9.73) than during baseline (M = 14.72, SD = 10.05), t (29) = 2.22, p = .035, d = .18. Biomarker Data: Cortisol levels were significantly higher at fasting (M = .15 μg/dL SD = .06) than at baseline (M = .19 μg/dL, SD = .07), t(32) = 3.16, p = .003, d = 0.25. IL-1β levels were significantly higher at fasting (M = 29.57 pg/mL SD = 23.51) than at baseline (M = 21.24 pg/mL, SD = 17.55), t(32) = -2.44, p = .02. There was not a significant difference in IL-6 levels between fasting (M = 6.06 pg/mL SD = 7.05) and baseline (M = 7.89 pg/mL, SD = 11.56), p > .05. Conclusions Overall, our findings show that a short-term fast does not benefit cognitive processes, and in fact, results in an increase in mind wandering and an increase in false alarms during an attention task. In addition, our data suggest that short-term fasting can alter cortisol and inflammation due to short-term changes in energy demands and that anti-inflammatory processes and beneficial cognitive changes likely require, either a longer fasting or intermittent fasting. (Suppl 1):A4 Background Prior research has shown that HMB supplementation may have a positive effect on body composition; however, minimal research exists regarding its effects in Mixed Martial Arts (MMA) Fighters. Therefore, the purpose of the current study is to determine the effects of HMB supplementation on body composition in MMA fighters. Materials and Methods Sixteen competitive, healthy MMA fighters (29±3.5 yrs.; 178.5± 7.8 cm; males) completed a double-blinded, counterbalanced, two condition [HMB versus Placebo (Cellulose)] by two-time point [Pre-, Post-] study. The study consisted of subjects supplementing HMB (3 g daily) or placebo in conjunction with MMA training over a 6-week period. Body composition was assessed via the In-Body770® both pre-and post-intervention. Results There were no significant (p =0.471) differences between HMB and Placebo following the 6-weeks of training for weight (kilograms [kg]) (HMB Pre-84.6±10.8, Post-84.1±11.6; Placebo Pre-87.9±14.2, Post-87.9±13.5). There were also no significant (p = 0.095) differences for fat-free mass (kg) (HMB Pre-42.3±5.4, Post-41.8±5.
doi:10.1186/s12970-020-00352-x pmid:32473638 fatcat:s636fythxvcivbiajy5x7vzwle