Patrick M. Davitt

Postprandial triglyceride and free fatty acid metabolism in obese women after either endurance or resistance exercise

We investigated the effects of two exercise modalities on postprandial triglyceride (TG) and free fatty acid (FFA) metabolism. Sedentary, obese women were studied on three occasions in randomized order: endurance exercise for 60 min at 60-65% aerobic capacity (E), ~60 min high-intensity resistance exercise (R), and a sedentary control trial (C). After exercise, a liquid-mixed meal containing [U-(13)C]palmitate was consumed, and subjects were studied over 7 h. Isotopic enrichment (IE) of plasma TG, plasma FFA, and breath carbon dioxide compared with meal IE indicated the contribution of dietary fat to each pool. Total and endogenously derived plasma TG content was reduced significantly in both E and R compared with C (P < 0.05), with no effect of exercise on circulating exogenous (meal-derived) TG content. Exogenous plasma FFA content was increased significantly following both E and R compared with C (P < 0.05), whereas total and endogenous FFA concentrations were elevated only in E (P < 0.05) compared with C. Fatty acid (FA) oxidation rates were increased significantly after E and R compared with C (P < 0.05), with no difference between exercise modalities. The present results indicate that E and R may be equally effective in reducing postprandial plasma TG concentration and enhancing lipid oxidation when the exercise sessions are matched for duration rather than for energy expenditure. Importantly, tracer results indicated that the reduction in postprandial lipemia after E and R exercise bouts is not achieved by enhanced clearance of dietary fat but rather, is achieved by reduced abundance of endogenous FA in plasma TG.

The Effects of a Combined Resistance Training and Endurance Exercise Program in Inactive College Female Subjects: Does Order Matter?

Abstract Davitt, PM, Pellegrino, JK, Schanzer, JR, Tjionas, H, and Arent, SM. The effects of a combined resistance training and endurance exercise program in inactive college female subjects: Does order matter? J Strength Cond Res 28(7): 1937–1945, 2014—Although both endurance (E) and resistance (R) exercise improve various health and fitness variables, there is still debate regarding the optimal ordering of these modes of exercise within a concurrent bout. The purpose of this study was to determine the effects of performing E before R (E-R) or R before E (R-E) on strength, V[Combining Dot Above]O2max, and body composition over the course of an 8-week exercise program. Inactive college female subjects (N = 23; 19.8 ± 0.22 years; 61.0 ± 2.5 kg) were randomly assigned to either an E-R (n = 13) or an R-E (n = 10) group. Subjects trained 4 d·wk−1 over the 8-week study. The E portion consisted of 30 minutes of aerobic exercise at 70–80% heart rate reserve (HRR). The R portion used a 3-way split routine with subjects performing 3 sets of 8–12 repetitions for 5–6 different exercises using a load equal to 90–100% 10 repetition maximum. There were 2 days of testing before and after 8 weeks of training to determine performance and body composition. There were significant improvements in chest press (p < 0.001), leg press (p < 0.001), V[Combining Dot Above]O2max (p < 0.001), and lean body mass (LBM) (p = 0.005) across both groups. Weight significantly increased (p = 0.038), but percent body fat did not change (p = 0.46). There were no differences as a function of group (p > 0.267). There were significant improvements in performance and LBM over an 8-week concurrent training program in inactive college female subjects, regardless of the order in which R and E were performed. It seems that fitness markers improve similarly regardless of the order of R or E in a 4 d·wk−1 program in inactive female subjects. Therefore, the order of these modalities for beginning exercisers should be based on personal preference and to facilitate adherence.

The effects of a post-workout nutraceutical drink on body composition, performance and hormonal and biochemical responses in Division I college football players

Football players walk a fine line between optimal training and overtraining. Manipulating nutrient intake has the potential to maximize the biochemical environment necessary to induce peak performance and proper recovery. The purpose of this study was to examine the impact of supplementing the diet of Division I football players with a proprietary nutraceutical recovery drink on changes in performance, body composition, anabolic status, muscle damage, inflammation and oxidative stress over the course of a 7-week conditioning period immediately prior to preseason camp. At the beginning (trial 1) and end (trial 2) of a 7-week training phase, body composition, vertical jump and 225 lb bench press were assessed in Division I college football players (n ¼ 25). A 30 s Wingate Anaerobic Test plus eight 10 s intervals was used to examine power and biochemical responses. Blood samples were collected pre-, 0 and 60 min post-test for analysis of interleukin-6 (IL), 8-isoprostane (8-iso), cortisol (CORT) and resting testosterone:CORT (T:C) ratios. Athletes were randomly assigned to either an experimental group (EXP) receiving the nutraceutical drink (n ¼ 13) or a control group (CON) receiving an isocaloric equivalent (n ¼ 12). EXP had a significantly greater increase in peak power (P , 0.05) and significant decreases in percentage body fat and fat mass (P , 0.05). Multivariate ANOVA for repeated measures (RM MANOVA) revealed a significant test £ time £ group interaction (P , 0.05) for changes in CORT, IL-6 and 8-iso from trial 1 to trial 2. Follow-ups revealed no significant differences between groups at trial 1 for any of the variables. At trial 2, EXP had significantly lower CORT at rest (P ¼ 0.01) and 60 min post-test (P ¼ 0.001). Additionally, IL-6 was significantly different between EXP and CON at 0 (P , 0.01) and 60 min post-test (P , 0.01), with CON having an elevated IL-6 response. There were also differences in both 8-iso and creatine kinase at all time points at trial 2, with CON having higher levels (P , 0.02.). There were significant differences between groups in T:C ratio changes (P , 0.05), with EXP having an improved T:C ratio. It appears that supplementing the post-workout diet of Division I college football players with a nutraceutical recovery drink has favourable effects on body composition, peak power output and biochemical markers. Based on differences between groups that emerged at rest at trial 2, it appears that this supplement positively impacts both acute and chronic physiological responses indicative of improved recovery.