ECSS Paris 2023: OP-PN02
INTRODUCTION: The decline in skeletal muscle mass, strength and function (sarcopenia) is observed from the 4th decade of life and accelerates beyond 60 years of age. Sarcopenia is underscored by an impaired muscle protein synthesis (MPS) response to anabolic stimuli, including protein feeding and resistance exercise training (RET). Sex-based differences in acute MPS have been reported and may explain divergence in sarcopenia trajectories and muscle adaptation to RET between older males and females. A paucity of studies shows no differences in acute MPS have been reported in middle-aged males and females. Measurement of longer-term free-living daily MPS rates in middle-to-older aged males and females, consuming a typical diet with or without RET, would provide valuable insight on sex-based differences in muscle mass regulation. METHODS: Healthy middle-to-older aged males (n=13, 60±7 y) and females (n=12, 63±5 y) completed a 10-day experimental investigation in which they consumed a controlled diet containing 1g/kg day-1 protein and completed high-volume unilateral knee extension RET every other day. Body fat was measured via dual x-ray absorptiometry (DXA). Deuterium oxide preload of 400ml and 50ml daily top ups was consumed, and muscle biopsy samples were obtained on days 0 and 10 to determine free-living daily myofibrillar protein synthesis (iMyoPS) rates in trained and untrained legs. Statistical differences for sex only were identified using independent samples T-test or 2-way repeated measures ANOVA for sex and training differences. Statistical significance was set at P<0.05 with data shown as mean ± standard deviation. RESULTS: Total deuterium body water enrichment was significantly higher in middle-to-older age males than females (0.63 ± 0.14 APE vs 0.78 ± 0.14 APE, P=0.012). DXA-derived body fat was significantly different between sexes (24.7 ± 5.3% males vs 37.2 ± 5.8% females, P<0.001). Training load in RET did not statistically differ between sexes (P=0.058), but weight lifted was significantly different (males 42.9 ± 16.9 kg vs females 31.5 ± 8.4 kg, P<0.001). Daily iMyoPS rates in the untrained leg did not significantly differ between sexes (1.26 ± 0.22 %day-1 for males vs 1.37 ± 0.26 %day-1 for females, P=0.246). Notably, in the trained leg, there was also no significant difference in daily iMyoPS rates between sexes (1.45 ± 0.16 %day-1 in males vs 1.48 ± 0.27 %day-1 in females, P=0.823). Daily iMyoPS rates in the trained leg were significantly higher than the untrained leg (8% higher in females, P<0.001 and 16% higher in males, P<0.001) with no significant difference between sexes (P=0.099). CONCLUSION: Free-living daily iMyoPS rates did not differ between middle-to-older aged males and females consuming a typical protein-containing diet. RET elevated daily iMyoPS rates compared to the untrained leg in the middle-to-older aged males and females, with no differences observed between sexes.
Read CV Marie KorzepaECSS Paris 2023: OP-PN02
INTRODUCTION: Numerous studies have demonstrated the ergogenic effect of acute caffeine intake in different sports actions. In resistance exercise, caffeine enhances velocity and power production at different loads and exercise types (e.g., bench press or back squat). However, it remains unclear whether the acute ergogenic effects of this supplement can accumulate over consecutive exercise sessions, specifically if prolonged caffeine intake before resistance exercise enhances neuromuscular adaptations. Therefore, this study aimed to evaluate the effect of pre-exercise caffeine intake during 8-weeks of velocity-based resistance training. METHODS: Forty-eight resistance-trained participants (male/female: 24/24; age: 24±4 years; training experience: 3.8±3.3 years; 1RM/kg bench press: 1.1±0.3; 1RM/kg back squat: 1.6±0.6; caffeine intake: 50.5±50.9 mg/day) participated in a double-blind, randomized, placebo- controlled trial. Participants completed an 8-week, twice-weekly velocity-based resistance training for bench press and back squat exercises at progressive loads (70-85%1RM). Four sets were performed per exercise until a 20% velocity loss occurred. Sixty minutes pre-exercise, they ingested 3 mg/kg of caffeine or placebo. Pre- and post-training tests included 1RM, muscular strength and power tests at 25%, 50%, 75%, 90% 1RM, and muscular endurance at 65% 1RM performing one set until task failure. Movement velocity was monitored in all cases. Moreover, acute caffeine effects were assessed before and after the intervention. RESULTS: Resistance training significantly increased 1RM in both bench press and back squat (13-19%, P<0.001), with caffeine supplementation resulting in greater improvements than placebo in bench press for both sexes (5.5%, P=0.043) and in back squat specifically for females compared to males (8% vs 2%, P=0.021). In bench press at 25% and 50%1RM, caffeine increased mean velocity (7% vs 14%, P=0.050; 0.5% vs 9%, P=0.010) and mean power (17% vs 38%, P=0.047; 12% vs 20%, P=0.041) compared to placebo. In back squat at 25%, 50% and 75%1RM, caffeine increased mean velocity (3% vs 20%, P=0.001; 1% vs 13%, P=0.001; 1% vs 16%, P=0.001) and mean power (4% vs 21%, P=0.006; 3% vs 15%, P=0.004; 6% vs 11%, P=0.049) compared to placebo. No sex differences were detected. Muscular endurance increased mean and peak power post-training in all groups (P=0.001). Also, similar acute caffeine effect was found pre- and post-training. CONCLUSION: Caffeine intake (3 mg/kg of body mass) before resistance exercise enhances 1RM and promotes a higher mean and peak velocity at 25-50% in bench press and 25-75% in back squat exercise after 8-weeks of training in both male and female participants. Therefore, prolonged pre- exercise caffeine intake accelerates neuromuscular performance adaptations to resistance exercise to a similar extent in male and female participants.
Read CV Juan Jesús Montalvo AlonsoECSS Paris 2023: OP-PN02
INTRODUCTION: Low-grade inflammation, characterized by elevated adipokines, is a hallmark of obesity and defining feature of metabolic syndrome (MetS). Time-restricted eating (TRE, 8 hours eating/16 hours fasting) and resistance training (RT) are both effective strategies for reducing low-grade inflammation markers and improving metabolic health. Yet, their combined effects on low-grade inflammation among people with MetS remain unclear. METHODS: In a randomized controlled trial, 76 adults with MetS (age: 50.4 ± 5.3 years, BMI: 31.4 ± 3.9 kg/m2) were assigned to one of three groups for 10 weeks: normal diet with RT (ND+RT), TRE alone, or TRE combined with RT (TRE+RT). The ND+RT group followed a standard, unrestricted eating pattern, while the TRE groups limited food intake to 12:00–8:00 PM. All groups adhered to iso-caloric diets with 1.5 g/kg/day of protein intake. conducted three times per week, with up to three participants per session, each lasting 60 minutes and comprising nine full-body exercises targeting major muscle groups. Body composition was assessed using dual-energy X-ray absorptiometry (DXA) and serum levels of leptin, TNF-α, and IL-6 were measured pre- and post-intervention. Statistical analyses included paired t-tests for within-group changes, ANCOVA for between-group comparisons, and Pearson correlations to examine associations between inflammatory markers and body composition. RESULTS: Of the 76 participants enrolled, 68 completed the study, with a 95% compliance rate; TRE alone (n=23), ND+RT (n=23), and TRE+RT (n=22). Only TRE+RT group exhibited significant reductions in IL-6 (-0.36±0.53 pg/ml, p=0.01) and TNF-α (-0.74±1.3 pg/ml, p=0.01) compared to baseline, with ANCOVA confirming greater reductions in TRE+RT compared to TRE alone (IL-6: p=0.01; TNF-α: p=0.03). Fat mass decreased significantly in all groups (TRE+RT: -2.4 ± 1.1 kg, ND+RT: -2.1 ± 1.8 kg, TRE Alone: -1.4 ± 1.4 kg; p < 0.001 for all). However, significant leptin reductions were observed only in ND+RT (-1.40 ± 2.0 ng/ml, p = 0.003) and TRE+RT (-2.80 ± 2.0 ng/ml, p = 0.008), with ANCOVA indicating significantly greater reductions in TRE+RT compared to TRE alone (p = 0.03). Notably, a strong positive correlation between fat mass reduction and leptin decline was observed only in ND+RT (r=0.61, p=0.002), whereas in TRE+RT, leptin reductions occurred independently of fat mass changes (r=-0.12, p=0.39), suggesting a potential distinct regulatory mechanism for leptin in this intervention. CONCLUSION: Combining TRE and RT result in more pronounced reductions in leptin, IL-6, and TNF-α levels. These findings suggest that TRE combined with RT may modestly reduce low-grade inflammation and improve metabolic health in individuals with MetS.
Read CV Roi YavetzECSS Paris 2023: OP-PN02