2016 Murphy and Koehler 2020 Gentil et al.
#Testout lab 6.4.6 full
The full texts of these articles were then screened 36 of these studies (Greene et al. With respect to the studies' abstracts, 51 of the reviewed studies were chosen to be potentially relevant for data analysis. Although vigor was negatively affected in both groups, other mood parameters did not change. Whether these advantages are due to the high-protein intake cannot be clarified and warrants further study. Muscle contractility was not negatively altered by this form of energy restriction. Notably, it is unknown whether protein intake at 2.8 g/kg fat-free-mass prevented larger decreases in lean body mass. 116) decreased significantly in the ER group and the CG, respectively.ĭiscussion: The present data show that a high-protein intake alone was not able to prevent lean mass loss associated with a 6-week moderate energy restriction in college students. Results: The ER group revealed greater reductions in body mass (Δ -3.22 kg vs. rectus femoris were examined with Tensiomyography and MyotonPRO at weeks 1, 3, and 5 along with sleep (PSQI) and mood (POMS). Body composition was assessed weekly using multifrequency bioelectrical impedance analysis. Both groups had their protein intake matched at 2.8 g/kg fat-free-mass and continued their habitual training throughout the study. Materials and Methods: After 1 week of body mass maintenance (45 kcal/kg), 28 male college students not performing resistance training were randomized to either the energy-restricted (ER, 30 kcal/kg, n = 14) or the eucaloric control group (CG, 45 kcal/kg, n = 14) for 6 weeks. However, it is unclear whether a high protein intake is able to maintain muscle mass and contractility in the absence of resistance training. Since all of these studies differ in total energy deficit, protein intake, sleep duration, baseline body fat, and type of physical activity performed, which are all known to significantly influence lean body mass change (Heymsfield et al., 2011), the exact reasons for the inherent interstudy differences remain unclear.īackground: It is often advised to ensure a high protein intake during energy-restricted diets.
While most of the studies revealed that energy restriction was associated with a significant lean body mass loss (Karila et al., 2008 Pikosky et al., 2008 Morton et al., 2010 Pasiakos et al., 2013 Rhyu and Cho, 2014), ranging from 34% (∼-1200 kcal/day Morton et al., 2010) to 84% (∼-2500 kcal/day Karila et al., 2008) of the total mass lost per week, some studies reported no significant lean body mass change during energy restriction (Huovinen et al., 2015 Wilson et al., 2015). Various studies examining the impact of energy restriction in active individuals have been conducted (Karila et al., 2008 Pikosky et al., 2008 Morton et al., 2010 Wilson et al., 2012 Pasiakos et al., 2013 Rhyu and Cho, 2014 Huovinen et al., 2015). In conclusion, altered acid-base balance but improved weight bearing power performance was observed without negative consequences on serum hormones and FFM after a four-week weight reduction of 0.5 kg / week achieved via reduced carbohydrate but maintained high protein intake. Finally, athletes with a fat percentage 10% or over at the baseline were able to preserve FFM.
The counter-movement jump and 20-m sprint time improved consistently (p ≤ 0.05) only in HWR, by 2.6 ± 2.5 cm and 0.04 ± 0.04 s, respectively. Caion and pH decreased (p ≤ 0.05) only in HWR (3.1 ± 2.8 % and 0.8 ± 0.8 %, respectively), whereas HCO3- declined (p ≤ 0.05) in both groups by 19.3 ± 6.2 % in HWR and by 13.1 ± 8.5 % in LWR. Fat-free mass (FFM), serum testosterone, cortisol, and SHBG did not change significantly. Furthermore, total body mass and fat mass decreased (p ≤ 0.05) only in HWR by 2.2 ± 1.0 kg and 1.7 ± 1.6 kg, respectively. Energy and carbohydrate intake decreased significantly (p ≤ 0.05) only in HWR by 740 ± 330 kcal / day and 130 ± 29 g / day, respectively. Eight participants were assigned to a high weight reduction group (HWR energy restriction 750 kcal / day), and seven to a low weight reduction group (LWR energy restriction 300 kcal / day).
The aim of this study was to investigate the effects of a four-week weight reduction period (WRP) with high protein and reduced carbohydrate intake on body composition, explosive power, speed, serum hormones and acid-base balance in male track and field jumpers and sprinters.