Effects of a CrossFit Training Program on Body Composition and Hematological Parameters in Young Soccer Players

International audienceThe study aimed to identify the effects of CrossFit training on body composition and hematological parameters in young soccer players. Forty soccer players voluntarily took part in this study, they were divided randomly into two equal groups: Experimental group (N=20) underwent a 12 weeks of CrossFit training program, and the control group (N=20) underwent 12 weeks of traditional training. Body composition and hematological parameters were measured before and after the experiment among both groups. As results, a significant time x group interaction effect was observed for body mass index (p=0.99; ES=0.45), body fat percentage (p=0.19; ES=0.36), and muscle mass (p=0.16; ES=0.57), which indicate a positively significant change of body mass index and body fat percentage, muscle mass (p<0.05). While a significant group x time effect was reported for body fat mass (p=0.04, ES=0.43) and basal metabolic rate (p=0.005, ES=0.55), with favor for experimental group compared to control group. Additionally results showed a statistically significant group x time effect for Hemoglobin (p=0.001; ES=0.24) Red blood cells (p=0.04, ES=0.56) and Hematocrit (p=0.007; ES=0.36) with favor for EG in comparison with CG group, an increasing was presents for all previous parameters respectively among experimental group (p<0.001). However, no statistically significant effect of group x time was indicated for platelets (p=0.16; ES=0.58), significant increasing was reported for both groups. CrossFit exercise program can be recommended as an effective program in enhancing and adjusting the vital indicators of young soccer players and improve performance

Ramadan Intermittent Fasting and Plasma Volume Variations in Individuals with Different Body Weights

International audienceBackground: There is increasing awareness of the physiological effects of Ramadan intermittent fasting (RIF) in obese subjects. However, there are no data on the effects of RIF on plasma volume changes (ΔPV) in individuals with different body weights. Background and Objectives: This study investigated the effects of RIF on ΔPV in normal-weight (NW) and overweight (OW) adult men, and adult men with obesity (OB) and severe obesity (SO). Materials and Methods: Thirty-two male subjects (32) were divided into four groups (n = 8 per group) according to their body mass index (BMI): normal weight (NW) (BMI < 25 kg/m2; age = 27.4 ± 3.8), overweight (OW) (BMI between 25 and 29.9 kg/m2; age = 26.8 ± 3.7), obese subjects (OB) (BMI between 30 and 34.9 kg/m2; age = 25.6 ± 2.9), and severely obesity (SO) (BMI between 35 and 40 kg/m2; age = 24.0 ± 4.1). Blood samples were collected for 24 h on 4 different occasions, at T0 before the start of the Ramadan month, at T1 15 days after the start of Ramadan, at T2 one day after the end of Ramadan, and at T3 on the 21st day after the end of Ramadan to determine ΔPV. All groups completed their fasting rituals for the 30 days of Ramadan. Results: A significant group × time effect occurred for body mass (p = 0.001; ES = 0.53), BMI (p = 0.001; ES = 0.53), and body fat percentage (p = 0.001; ES = 0.52). Post hoc tests indicated reductions in body mass in OB and SO at T1 (p = 0.03; ES = 0.21 and p = 0.002; ES = 0.12) and T2 (p = 0.03; ES = 0.31 and p = 0.02; ES = 0.23), reductions in BMI in OB and SO at T1 (p = 0.04; ES = 0.35 and p = 0.03; ES = 0.42) and T2 (p = 0.03; ES = 0.52 and p = 0.005; ES = 0.48), and reductions in body fat percentage only in OB AT T1 (p = 0.002; ES = 0.31) and T2 (p = 0.001; ES = 0.17). A significant group × time effect occurred for hematocrit (p = 0.02; ES = 0.34), hemoglobin (p = 0.01; ES = 0.35), and ΔPV (p = 0.02; ES = 0.18). Post hoc tests indicated increases in hematocrit in OB at T2 (p = 0.03; ES = 0.36) and hemoglobin in OB and SO at T1 (p = 0.03; ES = 0.35 and p = 0.002; ES = 0.32) and T2 (p = 0.003; ES = 0.21 and p = 0.002; ES = 0.33). There were also increases in ΔPV in OB at T1 and T2 (p = 0.002; ES = 0.25 and p = 0.003; ES = 0.22) and in SO only at T2 (p = 0.02; ES = 0.37). Contrast analysis indicated that NW was significantly lower than the grand mean of OW, Ob, and SO for all anthropometric and PVV variables (all p < 0.05). Conclusions: The effects of RIF on ΔPV and anthropometric characters was greater in obese individuals compared to normal-weight and overweight participants, suggesting that the improvements in body composition and ΔPV produced by RIF could positively influence obesity

The Effects of Combined Versus Single-Mode Resistance and Repeated Sprint Training on Physical Fitness, Hematological Parameters, and Plasma Volume Variations in Highly Trained Soccer Players

International audienceObjective: We examined the effects of eight weeks of single-mode resistance, repeated sprint training, and the combination of the two programs on selected measures of physical fitness (muscle power, speed, and body composition), hematological parameters, and plasma volume variations in highly trained soccer players. Sixty male soccer players from the Tunisian national Ligue were randomly allocated to a resistance training group (RTG), a repeated sprint training group (RSTG), a combined resistance and repeated sprint training group (CTG), or an active control group (CG, soccer training only). The training volumes were similar between groups. Before and after training, we examined body composition, squat jump (SJ), countermovement jump (CMJ), sprint 30 m (S30), repeated-sprint sequences (RSSs), hematocrit, hemoglobin, mean hemoglobin concentration (MHC), and plasma volume. Significant group-by-time interactions were recorded for the RSS indices, SJ, and S30 (p < 0.039], 0.1< ηp2 < 0.49]), as well as the hematological parameters (p = 0.0001–0.045, 0.11 < ηp2 < 0.46). In terms of physical fitness, using post hoc tests, the CTG showed significantly greater gains compared to the RSTG, RTG, and the CG on the best time index of the RSSs (p = 0.008; d = 4.1), SJ (p = 0.004; d = 4.18) and 30 m linear sprint time (p = 0.008; d = 3.84). Body fat percentage also decreased significantly in the CTG compared to all other groups (p < 0.005, 0.21 < d< 0.35). Regarding hematological parameters (i.e., hemoglobin and hematocrit), the CTG, RSTG, and RTG showed significant decreases (p < 0.05) in their hemoglobin and hematocrit values compared to the CG (p < 0.05, 0.11 < d< 2.22]). Eight weeks of combined training compared to single-mode training was found to be more effective in improving fitness measures in highly trained soccer players. However, there appeared to be no consensus regarding the effect of single and combined repeated-sprint and resistance training on the hematological system