A Novel Plant-Based Protein Has Similar Effects Compared to Whey Protein on Body Composition, Strength, Power, and Aerobic Performance in Professional and Semi-Professional Futsal Players

Introduction

The effects of dietary protein on body composition and physical performance seemingly depend on the essential amino acid profile of the given protein source, although controversy exists about whether animal protein sources may possess additional anabolic properties to plant-based protein sources.

Purpose

To compare the effects of a novel plant-based protein matrix and whey protein supplementation on body composition, strength, power, and endurance performance of trained futsal players.

Methods

Fifty male futsal players were followed during 8 weeks of supplementation, with 40 completing the study either with plant-based protein (N = 20) or whey protein (N = 20). The following measures were assessed: bone mineral content, lean body mass, and fat mass; muscle thickness of the rectus femoris; total body water; blood glucose, hematocrit, C-reactive protein, aspartate aminotransferase, alanine aminotransferase, creatine kinase, creatinine, and estimated glomerular filtration rate; salivary cortisol; maximal strength and 1-RM testing of the back squat and bench press exercises; muscle power and countermovement jump; VO2max and maximal aerobic speed. Subjects were asked to maintain regular dietary habits and record dietary intake every 4 weeks through 3-day food records.

Results

No differences in any variable were observed between groups at baseline or pre- to post-intervention. Moreover, no time*group interaction was observed in any of the studied variables, and a time effect was only observed regarding fat mass reduction.

Conclusions

Supplementing with either a novel plant-based protein matrix or whey protein did not affect any of the variables assessed in high-level futsal players over 8 wks. These results suggest that whey protein does not possess any unique anabolic properties over and above those of plant-based proteins when equated to an essential amino acid profile in the population studied. Furthermore, when consuming a daily protein intake >1.6 g/kg BW.day−1, additional protein supplementation does not affect body composition or performance in trained futsal players, regardless of protein type/source.

Editorial: New Training Strategies and Evaluation Methods for Improving Health and Physical Performance

Physical activity is among the most effective methods for improving health, body composition, and physical function, and its practice is suitable for every population [...].

Bioelectrical Impedance Vector Analysis Discriminates Aerobic Power in Futsal Players: The Role of Body Composition

Aims: The present study aimed to assess the ability of bioelectrical impedance vector analysis (BIVA) in discriminating fitness levels in futsal players, exploring the association of body composition and bioelectrical parameters with aerobic power. Methods: Forty-eight professional futsal players (age 23.8 ± 5.3 years) were involved in a cross-sectional study during their pre-season phase. Fat mass (FM) and muscle mass were determined by dual-energy X-ray absorptiometry. VO2max was obtained by indirect calorimetry through a graded exercise test performed on a treadmill. Bioelectrical resistance (R), reactance (Xc), and phase angle (PhA) were directly measured using a foot-to-hand bioimpedance technology at a 50 kHz frequency. Bioelectric R and Xc were standardized for the participants’ height and used to plot the bioimpedance vector in the R-Xc graph according to the BIVA approach. Results: The participants divided into groups of VO2max limited by tertiles showed significant differences in mean vector position in the R-Xc graph (p < 0.001), where a higher VO2max resulted in a longer vector and upper positioning. FM, muscle mass, and PhA differed (p < 0.01) among the athletes grouped by tertiles of VO2max, where athletes with a greater aerobic power showed a lower percentage of FM and a higher percentage of muscle mass and PhA. FM and PhA were associated with VO2max (FM: r = −0.658, p < 0.001; PhA: r = 0.493, p < 0.001). These relationships remained significant after adjusting for age and body mass (FM: ß = −0.335, p = 0.046; PhA: ß = 0.351, p = 0.003). Conclusions: Bioelectrical impedance vectors positioned on the lower pole of the R-Xc graph identified futsal players with a lower VO2max, while longer vectors corresponded to a greater aerobic power. Additionally, PhA, that describes the vector direction, was positively associated with VO2max, while a higher FM negatively affected VO2max in the futsal players. BIVA and PhA evaluation may represent a valid support for screening the aerobic fitness level in professional futsal players, when more sophisticated assessment methods are not available.

The effects of phosphatidic acid on performance and body composition - a scoping review

Phosphatidic acid (PA) is a lipid mediator proposed to increase muscle protein synthesis via direct stimulation of the mammalian target of rapamycin (mTOR) and may act as an anabolic supplemental aid. Evidence on the effectiveness of PA as an anabolic supplement is equivocal. We aimed to systematically assess the effect of PA on performance and body composition. Due to the small number of studies, this is a scoping review. A comprehensive search was performed in Pubmed, SPORTDiscus and Web of Science, from the 1 January 2010 to the 31 August 2020. Our search retrieved 2009 articles, which when filtered, resulted in six studies, published between 2012 and 2019, which were analysed further. Five studies were performed in adult male populations and one in an elderly male population. From these, three studies suggested no effect of PA on lean body mass , while the remaining showed a possible positive effect (body composition and performance improvements). In one of these, the supplement included other potentially anabolic substances, precluding an isolated effect of PA. After a thorough analysis of the studies included, the evidence does not support the supplementation with PA to increase performance or improve body composition in young or elderly men.

Effectiveness of a lifestyle weight-loss intervention targeting inactive former elite athletes: the Champ4Life randomised controlled trial

OBJECTIVES

Many athletes struggle in managing the end of their career, often gaining weight and adopting unhealthy lifestyles. Lifestyle programmes targeting former athletes who have gained substantial fat mass (FM) postsports career are lacking. We studied the effects of the Champ4Life programme on body composition and other health-related outcomes in former elite athletes with overweight or obesity.

METHODS

Ninety-four former athletes(42.4±7.3 y, 34.0% female) were recruited and randomly assigned to either an intervention group (IG; n=49) or a control group (CG; n=45). The IG attended 12 educational sessions addressing physical activity, weight management and nutrition. They also had a nutrition appointment aimed to prescribe a moderate caloric deficit(~300-500 kcal/day). Dual-energy X-ray absorptiometry was used to assess body composition. The Short-Form Health Survey-36 questionnaire was used to measure general health-related quality of life. Blood samples were collected to assess cardiometabolic health parameters.

RESULTS

At 12 months, the IG lost more weight (estimated difference (ED)=-5.3 kg; -6.9 to -3.8), total FM (ED=-4.1 kg; -5.4 to -2.8) and abdominal FM (ED=-0.49 kg; -0.64 to -0.33) than did the CG (p's<0.001). Cardiometabolic health markers also improved significantly (p<0.05) more in the IG at 12 months (insulin (ED=-4.9 μU/mL;-8.0 to -1.8); homoeostatic model assessment (ED=-1.2; -2.1 to -0.4); total cholesterol (ED=-21.8 mg/dL; -35.4 to -8.2); low-density lipoprotein (ED=18.2 mg/dL;-29.2 to -7.1)), as did quality-of-life dimensions (physical functioning (ED=11.7; 6.5 to 16.9); physical role (ED=17.6; 2.1 to 33.0); general health (ED=19.4; 11.4 to 27.4); vitality (ED=13.3; 5.3 to 21.3) and mental health (ED=12.3; 4.1 to 20.6)).

CONCLUSIONS

The Champ4Life programme was effective in substantially reducing total and abdominal FM while preserving fat-free mass and improving health-related markers. These findings will enable evidence-based decisions when implementing lifestyle interventions targeting retired elite athletes.

TRIAL REGISTERATION NUMBER

NCT03031951.

Generalized bioelectric impedance-based equations underestimate body fluids in athletes

The current study aimed: (i) to external validate total body water (TBW) and extracellular water (ECW) derived from athlete and non‐athlete predictive equations using radioisotope dilution techniques as a reference criterion in male and female athletes; (ii) in a larger sample, to determine the agreement between specific and generalized equations when estimating body fluids in male and female athletes practicing different sports. A total of 1371 athletes (men: n = 921, age 23.9 ± 1.4 y; women: n = 450, age 27.3 ± 6.8 y) participated in this study. All athletes underwent bioelectrical impedance analyses, while TBW and ECW were assessed with dilution techniques in a subgroup of 185 participants (men: n = 132, age 21.7 ± 5.1 y; women: n = 53, age 20.3 ± 4.5 y). Two specific and eight generalized predictive equations were tested. Compared to the criterion methods, no mean bias was observed using the athlete‐specific equations for TBW and ECW (−0.32 to 0.05, p > 0.05) and the coefficient of determination ranged from R² = 0.83 to 0.94. The majority of the generalized predictive equations underestimated TBW and ECW (p < 0.05); R² ranged from 0.66 to 0.89. In the larger sample, all the generalized equations showed lower TBW and ECW values (ranging from −6.58 to −0.19, p < 0.05) than specific predictive equations; except for TBW in female power/velocity (one equation) athletes and team sport (two equations). The use of generalized BIA‐based equations leads to an underestimation of TBW, and ECW compared to athlete‐specific predictive equations. Additionally, the larger sample indicates that generalized equations overall provided lower TBW and ECW compared to the athlete‐specific equations.

Phase Angle Is a Marker of Muscle Quantity and Strength in Overweight/Obese Former Athletes

Background: An increasing body of evidence indicates that the phase angle (PhA) can be applied as a marker of nutritional status, disease prognosis, and mortality probability. Still, it is not known whether PhA can be used as an indicator of muscular quantity and strength and maximal aerobic capacity in overweight/obese former highly active individuals, an understudied population. This study aimed to analyze the association between PhA with skeletal muscle mass, maximal isometric strength, and maximal aerobic capacity through VO2max, in overweight/obese and inactive former athletes. Methods: Cross-sectional information of 94 (62 males) former adult athletes (age: 43.1 ± 9.4 years old; body mass index: 31.4 ± 4.8 kg/m²) taking part in a weight-loss clinical trial was analyzed. Total fat and fat-free mass were determined by dual-energy X-ray absorptiometry, while skeletal muscle mass was predicted from appendicular lean soft tissue. Values for upper- and lower-body maximal isometric strength were assessed by handgrip and leg press dynamometry. VO2max was determined by indirect calorimetry through a graded exercise test performed on a treadmill. Results: PhA was associated with skeletal muscle mass (r = 0.564, p < 0.001), upper-body strength (r = 0.556, p < 0.001), lower-body strength (r = 0.422, p < 0.001), and VO2max (r = 0.328, p = 0.013). These relationships remained significant for skeletal muscle mass (β = 2.158, p = 0.001), maximal isometric strength (upper-body: β = 2.846, p = 0.012; low-er-body: β = 24.209, p = 0.041) after adjusting for age, sex, and fat mass but not for VO2max (β = −0.163, p = 0.098). Conclusion: Our findings indicated that former athletes with higher values of PhA exhibited greater muscle mass and strength, despite sex, age, and body composition, which suggests that this simple raw BI parameter can be utilized as an indicator of muscle quantity and functionality in overweight/obese former athletes.

Predictive equation for assessing appendicular lean soft tissue mass using bioelectric impedance analysis in older adults: Effect of body fat distribution

BACKGROUND

Low muscle mass is associated with sarcopenia and increased mortality. Muscle mass, especially that of the limbs, is commonly estimated by dual-energy X-ray absorptiometry (DXA) or bioimpedance analysis (BIA). However, BIA-based predictive equations for estimating lean appendicular soft tissue mass (ALST) do not take into account body fat distribution, an important factor influencing DXA and BIA measurements.

OBJECTIVES

To develop and cross-validate a BIA-based equation for estimating ALST with DXA as criterion, and to compare our new formula to three previously published models.

METHODS

One-hundred eighty-four older adults (140 women and 44 men) (age 71.5 ± 7.3 years, body mass index 27.9 ± 5.3 kg/m²) were recruited. Participants were randomly split into validation (n = 118) and cross-validation groups (n = 66). Bioelectrical resistance was obtained with a phase-sensitive 50 kHz BIA device.

RESULTS

A BIA-based model was developed for appendicular lean soft tissue mass [ALST (kg) = 5.982 + (0.188 × S² / resistance) + (0.014 × waist circumference) + (0.046 × Wt) + (3.881 × sex) - (0.053 × age), where sex is 0 if female or 1 if male, Wt is weight (kg), and S is stature (cm) (R² = 0.86, SEE = 1.35 kg)]. Cross validation revealed r² of 0.91 and no mean bias. Two of three previously published models showed a trend to significantly overestimate ALST in our sample (p < 0.01).

CONCLUSIONS

The new equation can be considered valid, with no observed bias and trend, thus affording practical means to quantify ALST mass in older adults.

Leucine metabolites do not induce changes in phase angle, bioimpedance vector analysis patterns, and strength in resistance trained men

We aimed to assess the effects of off-the-shelf leucine metabolite supplements on phase angle (PhA), bioimpedance vector analysis (BIVA) patterns and strength during an 8-week resistance training protocol. Fifty-three male participants were allocated into 4 groups: α-hydroxyisocaproic acid (n = 12, age = 30.9 ± 9.3 years), β-hydroxy-β-methylbutyrate free acid (n = 12, age = 31.0 ± 9.3 years), calcium β-hydroxy-β-methylbutyrate (n = 15, age = 32.1 ± 5.2 years) or placebo (n = 14, age = 28.9 ± 6.6 years). Bioimpedance parameters and 1-repetition maximum (1RM) for back squat and bench press were assessed at baseline and at the end of weeks 4 and 8. Additionally, fat-free mass and fat mass were evaluated by dual-energy X-ray absorptiometry. No statistically group by time interactions were found, even adjusting for age. PhA and vector did not change over the training period, while time-dependent increases were observed for 1RM back squat and 1RM bench press. A direct association was observed between PhA and 1RM bench press changes (whole sample), while PhA and strength were correlated throughout the study, even when adjusting for fat-free mass and percentage of fat mass. Leucine metabolites have no effect on PhA, BIVA patterns or strength during an 8-week resistance training program, in resistance trained subjects. The trial was registered at ClincicalTrials.gov: NCT03511092. Novelty: Supplementation with leucine metabolites is not a supplementation strategy that improves bioelectrical phase angle, cellular health, and strength after an 8-week resistance training program. When consuming a high protein diet, none of the α-hydroxyisocaproic acid, β-hydroxy-β-methylbutyrate free acid, and calcium β-hydroxy-β-methylbutyrate metabolites resulted in an ergogenic effect in resistance trained men.

Prediction of Somatotype from Bioimpedance Analysis in Elite Youth Soccer Players

The accurate body composition assessment comprises several variables, causing it to be a time consuming evaluation as well as requiring different and sometimes costly measurement instruments. The aim of this study was to develop new equations for the somatotype prediction, reducing the number of normal measurements required by the Heath and Carter approach. A group of 173 male soccer players (age, 13.6 ± 2.2 years, mean ± standard deviation; body mass index, BMI, 19.9 ± 2.5 kg/m²), members of the academy of a professional Italian soccer team participating in the first division (Serie A), participated in this study. Bioelectrical impedance analysis (BIA) was performed using the single frequency of 50 kHz and fat-free mass (FFM) was calculated using a BIA specific, impedance based equation. Somatotype components were estimated according to the Heath-Carter method. The participants were randomly split into development (n = 117) and validation groups (n = 56). New anthropometric and BIA based models were developed (endomorphy = −1.953 − 0.011 × stature²/resistance + 0.135 × BMI + 0.232 × triceps skinfold, R² = 0.86, SEE = 0.28; mesomorphy = 6.848 + 0.138 × phase angle + 0.232 × contracted arm circumference + 0.166 × calf circumference − 0.093 × stature, R² = 0.87, SEE = 0.40; ectomorphy = −5.592 − 38.237 × FFM/stature + 0.123 × stature, R² = 0.86, SEE = 0.37). Cross validation revealed R² of 0.84, 0.80, and 0.87 for endomorphy, mesomorphy, and ectomorphy, respectively. The new proposed equations allow for the integration of the somatotype assessment into BIA, reducing the number of collected measurements, the instruments used, and the time normally required to obtain a complete body composition analysis.

A New Strategy to Integrate Heath-Carter Somatotype Assessment with Bioelectrical Impedance Analysis in Elite Soccer Player

Easy-to-apply and quick methods for evaluate body composition are often preferred when assessing soccer teams. This study aimed to develop new equations for the somatotype quantification that would reduce the anthropometric measurements required by the Heath and Carter method, integrating the somatotype assessment to the bioelectrical impedance analysis (BIA). One hundred and seventy-six male elite soccer players (age 26.9 ± 4.5 years), registered in the Italian first division (Serie A), underwent anthropometric measurements and BIA. Endomorphy, mesomorphy, and ectomorphy were obtained according to the Heath and Carter method, while fat mass (FM) and fat free mass (FFM) estimated using a BIA-derived equation specific for athletes. The participants were randomly split into development (n = 117) and validation groups (n = 59, 1/3 of sample). The developed models including resistance2/stature, FM%, FFM, contracted arm and calf circumference, triceps, and supraspinal skinfolds had high predictive ability for endomorphy (R2 = 0.83, Standard Error of Estimate (SEE) = 0.16) mesomorphy (R2 = 0.80, SEE = 0.36), and ectomorphy (endomorphy (R2 = 0.87, SEE = 0.22). Cross validation revealed R2 of 0.80, 0.84, 0.87 for endomorphy, mesomorphy, and ectomorphy, respectively. The proposed strategy allows the integration of somatotype assessment to BIA in soccer players, reducing the number of instruments and measurements required by the Heath and Carter approach.

Body Water Content and Morphological Characteristics Modify Bioimpedance Vector Patterns in Volleyball, Soccer, and Rugby Players

Background: Bioimpedance vector analysis (BIVA) is a widely used method based on the interpretation of raw bioimpedance parameters to evaluate body composition and cellular health in athletes. However, several variables contribute to influencing BIVA patterns by militating against an optimal interpretation of the data. This study aims to explore the association of morphological characteristics with bioelectrical properties in volleyball, soccer, and rugby players. Methods: 164 athletes belonging to professional teams (age 26.2 ± 4.4 yrs; body mass index (BMI) 25.4 ± 2.4 kg/m²) underwent bioimpedance and anthropometric measurements. Bioelectric resistance (R) and reactance (Xc) were standardized for the athlete's height and used to plot the vector in the R-Xc graph according to the BIVA approach. Total body water (TBW), phase angle (PhA), and somatotype were determined from bioelectrical and anthropometric data. Results: No significant difference (p > 0.05) for age and for age at the start of competition among the athletes was found. Athletes divided into groups of TBW limited by quartiles showed significant differences in the mean vector position in the R-Xc graph (p < 0.001), where a higher content of body fluids resulted in a shorter vector and lower positioning in the graph. Furthermore, six categories of somatotypes were identified, and the results of bivariate and partial correlation analysis highlighted a direct association between PhA and mesomorphy (r = 0.401, p < 0.001) while showing an inverse correlation with ectomorphy (r = -0.416, p < 0.001), even adjusted for age. On the contrary, no association was observed between PhA and endomorphy (r = 0.100, p = 0.471). Conclusions: Body fluid content affects the vector length in the R-Xc graph. In addition, the lateral displacement of the vector, which determines the PhA, can be modified by the morphological characteristics of the athlete. In particular, higher PhA values are observed in subjects with a high mesomorphic component, whereas lower values are found when ectomorphy is dominant.

Fat-free Mass Bioelectrical Impedance Analysis Predictive Equation for Athletes using a 4-Compartment Model

Bioelectrical impedance analysis equations for fat-free mass prediction in healthy populations exist, nevertheless none accounts for the inter-athlete differences of the chemical composition of the fat-free mass. We aimed to develop a bioimpedance-based model for fat-free mass prediction based on the four-compartment model in a sample of national level athletes; and to cross-validate the new models in a separate cohort of athletes using a 4-compartment model as a criterion. There were 142 highly trained athletes (22.9±5.0 years) evaluated during their respective competitive seasons. Athletes were randomly split into development (n=95) and validation groups (n=47). The criterion method for fat-free mass was the 4-compartment model. Resistance and reactance were obtained with a phase-sensitive 50 kHz bioimpedance device. Athletic impedance-based models were developed (fat-free mass=- 2.261+0.327*Stature²/Resistance+0.525*Weight+5.462*Sex, where stature is in cm, Resistance is in Ω, Weight is in kg, and sex is 0 if female or 1 if male). Cross validation revealed R² of 0.94, limits of agreement around 10% variability and no trend, as well as a high concordance correlation coefficient. The new equation can be considered valid thus affording practical means to quantify fat-free mass in elite adult athletes.

Bioimpedance Vector Patterns Changes in Response to Swimming Training: An Ecological Approach

BACKGROUND AND AIM

Monitoring bioelectric phase angle (PhA) provides important information on the health and the condition of the athlete. Together with the vector length, PhA constitutes the bioimpedance vector analysis (BIVA) patterns, and their joint interpretation exceeds the limits of the evaluation of the PhA alone. The present investigation aimed to monitor changes in the BIVA patterns during a training macrocycle in swimmers, trying to ascertain if these parameters are sensitive to training load changes across a 13-week training period.

METHODS

Twelve national and international level swimmers (four females; eight males; 20.9 ± 1.9 years; with a competitive swimming background of 11.3 ± 1.8 years; undertaking 16-20 h of pool training and 4-5 h of dry-land training per week and 822.0 ± 59.0 International Swimming Federation (FINA) points) were evaluated for resistance (R) and reactance (Xc) using a single frequency phase sensitive bioimpedance device at the beginning of the macrocycle (M1), just before the beginning of the taper period (M2), and just before the main competition of the macrocycle (M3). At the three-time assessment points, swimmers also performed a 50 m all-out first stroke sprint with track start (T50 m) while time was recorded.

RESULTS

The results of the Hotelling T2 test showed a significant vector displacement due to simultaneous R and Xc changes (p < 0.001), where shifting from top to bottom along the major axis of the R-Xc graph from M1 to M2 was observed. From M2 to M3, a vector displacement up and left along the minor axis of the tolerance ellipses resulted in an increase in PhA (p < 0.01). The results suggest a gain in fluid with a decrease in cellular density from M1 to M2 due to decrements in R and Xc. Nevertheless, the reduced training load characterizing taper seemed to allow for an increase in PhA and, most importantly, an increase of Xc, thus demonstrating improved cellular health and physical condition, which was concomitant with a significant increase in the T50 m performance (p < 0.01).

CONCLUSIONS

PhA, obtained by bioelectrical R and Xc, can be useful in monitoring the condition of swimmers preparing for competition. Monitoring BIVA patterns allows for an ecological approach to the swimmers' health and condition assessment without resorting to equations to predict the related body composition variables.

The Cellular Composition of the Innate and Adaptive Immune System Is Changed in Blood in Response to Long-Term Swimming Training

Competitive swimming requires high training load cycles including consecutive sessions with little recovery in between which may contribute to the onset of fatigue and eventually illness. We aimed to investigate immune changes over a 7-month swimming season. Fifty-four national and international level swimmers (25 females, 29 males), ranging from 13 to 20 years of age, were evaluated at rest at: M1 (beginning of the season), M2 (after the 1st macrocycle’s main competition), M3 (highest training load phase of the 2nd macrocycle) and M4 (after the 2nd macrocycle’s main competition) and grouped according to sex, competitive age-groups, or pubertal Tanner stages. Hemogram and the lymphocytes subsets were assessed by automatic cell counting and by flow cytometry, respectively. Self-reported Upper Respiratory Symptoms (URS) and training load were quantified. Although the values remained within the normal range reference, at M2, CD8⁺ decreased (M1 = 703 ± 245 vs. M2 = 665 ± 278 cell μL⁻¹; p = 0.032) and total lymphocytes (TL, M1 = 2831 ± 734 vs. M2 = 2417 ± 714 cell μL⁻¹; p = 0.007), CD3⁺ (M1 = 1974 ± 581 vs. M2 = 1672 ± 603 cell μL⁻¹; p = 0.003), and CD4⁺ (M1 = 1102 ± 353 vs. M2 = 929 ± 329 cell μL⁻¹; p = 0.002) decreased in youth. At M3, CD8⁺ remained below baseline (M3 = 622 ± 245 cell μL⁻¹; p = 0.008), eosinophils (M1 = 0.30 ± 0.04 vs. M3 = 0.25 ± 0.03 10⁹ L^–1; p = 0.003) and CD16⁺56⁺ (M1 = 403 ± 184 vs. M3 = 339 ± 135 cell μL⁻¹; p = 0.019) decreased, and TL, CD3⁺, and CD4⁺ recovered in youth. At M4, CD19⁺ were elevated (M1 = 403 ± 170 vs. M4 = 473 ± 151 cell μL⁻¹; p = 0.022), CD16⁺56⁺ continued to decrease (M4 = 284 ± 131 cell μL⁻¹; p < 0.001), eosinophils remained below baseline (M4 = 0.29 ± 0.05 10⁹ L^–1; p = 0.002) and CD8⁺ recovered; monocytes were also decreased in male seniors (M1 = 0.77 ± 0.22 vs. M4 = 0.57 ± 0.16 10⁹ L^–1; p = 0.031). The heaviest training load and higher frequency of URS episodes happened at M3. The swimming season induced a cumulative effect toward a decrease of the number of innate immune cells, while acquired immunity appeared to be more affected at the most intense period, recovering after tapering. Younger athletes were more susceptible at the beginning of the training season than older ones.

Identifying Athlete Body Fluid Changes During a Competitive Season With Bioelectrical Impedance Vector Analysis

PURPOSE

To analyze the association between body fluid changes evaluated by bioelectrical impedance vector analysis and dilution techniques over a competitive season in athletes.

METHODS

A total of 58 athletes of both sexes (men: age 18.7 [4.0] y and women: age 19.2 [6.0] y) engaging in different sports were evaluated at the beginning (pre) and 6 months after (post) the competitive season. Deuterium dilution and bromide dilution were used as the criterion methods to assess total body water (TBW) and extracellular water (ECW), respectively; intracellular water (ICW) was calculated as TBW-ECW. Bioelectrical resistance and reactance were obtained with a phase-sensitive 50-kHz bioelectrical impedance analysis device; bioelectrical impedance vector analysis was applied. Dual-energy X-ray absorptiometry was used to assess fat mass and fat-free mass. The athletes were empirically classified considering TBW change (pre-post, increase or decrease) according to sex.

RESULTS

Significant mean vector displacements in the postgroups were observed in both sexes. Specifically, reductions in vector length (Z/H) were associated with increases in TBW and ICW (r = -.718, P < .01; r = -.630, P < .01, respectively) and decreases in ECW:ICW ratio (r = .344, P < .05), even after adjusting for age, height, and sex. Phase-angle variations were positively associated with TBW and ICW (r = .458, P < .01; r = .564, P < .01, respectively) and negatively associated with ECW:ICW (r = -.436, P < .01). Phase angle significantly increased in all the postgroups except in women in whom TBW decreased.

CONCLUSIONS

The results suggest that bioelectrical impedance vector analysis is a suitable method to obtain a qualitative indication of body fluid changes during a competitive season in athletes.

The Predictive Role of Raw Bioelectrical Impedance Parameters in Water Compartments and Fluid Distribution Assessed by Dilution Techniques in Athletes

The aims of this study were to analyze the usefulness of raw bioelectrical impedance (BI) parameters in assessing water compartments and fluid distribution in athletes. A total of 202 men and 71 female athletes were analyzed. Total body water (TBW) and extracellular water (ECW) were determined by dilution techniques, while intracellular water (ICW) was calculated. Fluid distribution was calculated as the ECW/ICW ratio (E:I). Phase angle (PhA), resistance (R) and reactance (Xc) were obtained through BI spectroscopy using frequency 50kHz. Fat (FM) and fat-free mass (FFM) were assessed by dual-energy X-ray absorptiometry. After adjusting for height, FM, FFM, age and sports category we observed that: PhA predicted ICW (females: β = 1.62, p < 0.01; males: β = 2.70, p < 0.01) and E:I (males and females: β = −0.08; p < 0.01); R explained TBW (females: β = −0.03; p < 0.01; males: β = −0.06; p < 0.01) and ECW (females: β = –0.02, p < 0.01; males: β = −0.03, p < 0.01) and ICW (females: β = –0.01, p < 0.053; males: β = –0.03 p < 0.01); and Xc predicted ECW (females: β = −0.06, p < 0.01; males: β = −0.12, p < 0.01). A higher PhA is a good predictor of a larger ICW pool and a lower E:I, regardless of body composition, age, height, and sports category. Lower R is associated with higher water pools whereas ECW expansion is explained by lower Xc. Raw BI parameters are useful predictors of total and extracellular pools, cellular hydration and fluid distribution in athletes.

Champ4life Study Protocol: A One-Year Randomized Controlled Trial of a Lifestyle Intervention for Inactive Former Elite Athletes with Overweight/Obesity

Preventive and educational programs directed to former elite athletes in the areas of healthy living are required. This is particularly relevant as obesity and health-related problems are observed in retired athletes, especially in those whose current levels of physical activity are below the recommendations. During their sports career, elite athletes are supported by a multidisciplinary team; upon retirement, no support is provided for the transition to a different lifestyle. So far, no program has been implemented to promote sustained healthy lifestyle behaviors in the post-career transition and evidence is lacking for such an intervention. Firstly, we aim to determine if Champ4life, a 1-year lifestyle intervention targeting inactive former athletes with overweight and obesity, is effective for reducing total and abdominal fat. Secondly, our purpose is to assess the effectiveness of the intervention on the levels of physical activity and sedentary behavior, resting energy expenditure, cardio-metabolic markers, physical fitness, energy balance components, eating self-regulation markers, and quality of life over 12 months. Champ4life is an evidence- and theory-based program using a randomized control trial design (intervention vs. control group) that will be conducted on 94 inactive former elite athletes with overweight and obesity. The first four months of the Champ4Life program include a nutritional appointment and 12 weekly, 90-min sessions. Classroom sessions seek to provide participants with key information and a toolbox of behavior change techniques to initiate and sustain long-term lifestyle changes. Participants will undergo baseline, 4-month, and 12-month measurements of body composition (primary outcomes), resting energy expenditure, physical fitness, metabolic markers, energy balance related-markers, and quality of life (secondary outcome). This trial will provide evidence on the effectiveness of the Champ4life program, a pioneer lifestyle intervention for retired athletes, offering tools for sustained changes in physical activity, sedentary behavior and diet, aiming to improve body composition and overall health-related markers.

Are predictive equations a valid method of assessing the resting metabolic rate of overweight or obese former athletes?

Athletes retiring from their sports career, an understudied population, are susceptible to become overweight/obese because of decreased energy expenditure not followed by a reduction in energy intake. Therefore, their energy requirements, through resting metabolic rate (RMR), should be accurately addressed for weight management purposes. This study aimed to determine the validity of predictive equations (PEq) for RMR estimation using indirect calorimetry as the reference method in a sample of overweight/obese former athletes. The study uses cross-sectional data collected during baseline measurements of a lifestyle intervention (NCT03031951). The RMR of 56 overweight/obese (31.5 (4.0 kg/m²)) individuals (78.6% male, 37.5% obese, 95.8 (14.8 kg), 174.2 (8.7 cm)) was measured by indirect calorimetry and predicted using seven PEq: Harris-Benedict, Cunningham, Schofield, FAO/WHO/UNU, Owen, Mifflin-St. Jeor, and Katch-McArdle. Dual-energy X-ray absorptiometry was used to assess body composition. The PEq overestimated the RMR measured by the indirect calorimetry, 70-300 kcal/day (4.3-14.9%). The linear regression between the reference and each of the PEq did not differ from the identity line with estimated values explaining around 50% of the variability of the measured values. The agreement between the methods was weak for all the PEq showing wide limits of agreement. The Harris-Benedict equation was the only one in which the difference between the methods was not related to the magnitude of the measured RMR. Given the weak performance of the various RMR models in overweight/obese former athletes, an effective weight management intervention based on estimated resting energy requirements may be compromised.

Leucine Metabolites Do Not Enhance Training-induced Performance or Muscle Thickness

Leucine metabolites, α-hydroxyisocaproic acid (α-HICA) and β-hydroxy-β-methylbutyrate (calcium, HMB-Ca and free acid, HMB-FA), have been proposed to augment resistance training-induced changes in body composition and performance.

PURPOSE

We aimed to conduct a double-blind randomized controlled pragmatic trial to evaluate the effects of off-the-shelf leucine metabolite supplements of α-HICA, HMB-FA, and HMB-Ca on resistance training-induced changes in muscle thickness and performance.

METHODS

Forty men were randomly assigned to receive α-HICA (n = 10, fat-free mass [FFM] = 62.0 ± 7.1 kg), HMB-FA (n = 11, FFM = 62.7 ± 10.5 kg), HMB-Ca (n = 9, FFM = 65.6 ± 10.1 kg), or placebo (PLA; n = 10, FFM = 64.2 ± 5.7 kg). The training program consisted of whole body thrice weekly resistance training for 8 wk (seven exercises per session, three to four sets per session, at 70%-80% one repetition maximum). Skeletal muscle thickness by ultrasound, performance measures, and blood measures (creatine kinase, insulin-like growth factor 1, growth hormone, cortisol, and total testosterone) were evaluated at baseline and at the end of weeks 4 and 8.

RESULTS

Time-dependent changes were observed for muscle thickness (P < 0.001), one repetition maximum bench press and squat (P < 0.001), Wingate peak power (P = 0.02), countermovement jump height (P = 0.03), power (P = 0.006), creatine kinase, insulin-like growth factor-1, growth hormone, and cortisol (all P < 0.001). No significant between-group or time-group interactions were observed.

CONCLUSIONS

No leucine metabolite resulted in any ergogenic effects on any outcome variable. Supplementation with leucine metabolites-α-HICA, HMB-FA, or HMB-Ca-is not a supplementation strategy that improves muscle growth and strength development in young adult men.

Usefulness of Reflection Scanning in Determining Whole-Body Composition in Broadly Built Individuals Using Dual-Energy X-ray Absorptiometry

Whole-body composition analysis by dual-energy X-ray absorptiometry (DXA) requires subjects to fit within the width limits of the DXA bed. To overcome this limitation, the aim of this study was to validate a partial scanning technique at which the upper left limb is deliberately left unscanned and measurements are "reflected" from the right-side upper limb. A Hologic Explorer-W densitometer was used in a sample of 189 participants, including athletes and nonathletes, ranging from underweight to obese (body mass index: 17.0-40.1 kg/m²). A whole-body scan was analyzed as the reference procedure to determine bone mineral content (BMC), lean soft tissue (LST), and fat mass (FM), and reanalyzed using a partial reflection scanning (RS) technique. RS estimates of BMC were associated with athletic status and differed significantly from reference estimates (p < 0.05). Also, the RS estimates of LST and FM were different (p < 0.05) from those of the reference whole-body scan, although differences were small (0.17 kg, -0.02 kg, and -0.10% for BMC, LST, and FM, respectively). The alternative procedure explained more than 99% of the reference scan variance with low limits of agreement (BMC: -13.8 to 23.9 g [athletes] and -6.3 to 18.0 g [nonathletes]; LST: -0.11 to 0.45 kg; FM: -0.22 to 0.17 kg). Regardless of body mass index, athletic status, and gender, RS is a useful and simple solution to be used in individuals wider than the DXA scan area. However, individual errors for BMC may be higher in athletes engaged in lateral dominant sports practice.

Leucine metabolites do not attenuate training-induced inflammation in young resistance trained men

Leucine metabolites may reduce training-induced inflammation; however, there is scant evidence for this assertion. We conducted a double-blind randomized controlled pragmatic trial where 40 male participants were allocated into 4 groups: α-hydroxyisocaproic acid group ([α-HICA], n = 10, Fat-free mass [FFM] = 62.0 ± 7.1 kg), β-hydroxy-β-methylbutyrate free acid group ([HMB-FA], n = 11, FFM = 62.7 ± 10.5 kg), calcium β-hydroxy-β-methylbutyrate group ([HMB-Ca], n = 9, FFM = 65.6 ± 10.1 kg) or placebo group ([PLA]; n = 10, FFM = 64.2 ± 5.7 kg). An 8-week whole-body resistance training routine (3 training sessions per week) was employed to induce gains in skeletal-muscle thickness. Skeletal muscle thickness (MT), one repetition maximum (1RM), interleukin-6 (IL-6), high-sensitivity C-reactive protein (hsCRP) and tumour necrosis factor alpha (TNF-α) were assessed at baseline and at the end of weeks 4 and 8. Time-dependent increases were detected from baseline to week 8 for MT (vastus lateralis: p = 0.009; rectus femoris: p = 0.018), 1RM (back squat: α-HICA, 18.5% ± 18.9%; HMB-FA, 23.2% ± 16%; HMB-Ca, 10.5% ± 13.8%; PLA, 19.7% ± 9% and bench press: α-HICA, 13.8% ± 19.1%; HMB-FA, 15.5% ± 9.3%; HMB-Ca, 10% ± 10.4%; PLA, 14.4 ± 11.3%, both p < 0.001), IL-6, hsCRP (both p < 0.001) and TNF-α (p = 0.045). No differences were found between groups at any time point. No leucine metabolite attenuated inflammation during training. Additionally, backwards elimination regressions showed that no circulating inflammatory marker consistently shared variance with the change in any outcome. Using leucine metabolites to modulate inflammation cannot be recommended from the results obtained herein. Furthermore, increases in inflammatory markers, from training, do not correlate with any outcome variable and are likely the result of training adaptations.

Accuracy of Bioelectrical Impedance Analysis in Estimated Longitudinal Fat-Free Mass Changes in Male Army Cadets

Introduction

Bioelectrical impedance analysis (BIA) is a practical and rapid method for making a longitudinal analysis of changes in body composition. However, most BIA validation studies have been performed in a clinical population and only at one moment, or point in time (cross-sectional study). The aim of this study is to investigate the accuracy of predictive equations based on BIA with regard to the changes in fat-free mass (FFM) in Brazilian male army cadets after 7 mo of military training. The values used were determined using dual-energy X-ray absorptiometry (DXA) as a reference method.

Materials and Methods

The study included 310 male Brazilian Army cadets (aged 17-24 yr). FFM was measured using eight general predictive BIA equations, with one equation specifically applied to this population sample, and the values were compared with results obtained using DXA. The student's t-test, adjusted coefficient of determination (R2), standard error of estimation (SEE), Lin's approach, and the Bland-Altman test were used to determine the accuracy of the predictive BIA equations used to estimate FFM in this population and between the two moments (pre- and post-moment).

Results

The FFM measured using the nine predictive BIA equations, and determined using DXA at the post-moment, showed a significant increase when compared with the pre-moment (p < 0.05). All nine predictive BIA equations were able to detect FFM changes in the army cadets between the two moments in a very similar way to the reference method (DXA). However, only the one BIA equation specific to this population showed no significant differences in the FFM estimation between DXA at pre- and post-moment of military routine. All predictive BIA equations showed large limits of agreement using the Bland-Altman approach.

Conclusion

The eight general predictive BIA equations used in this study were not found to be valid for analyzing the FFM changes in the Brazilian male army cadets, after a period of approximately 7 mo of military training. Although the BIA equation specific to this population is dependent on the amount of FFM, it appears to be a good alternative to DXA for assessing FFM in Brazilian male army cadets.

No effect of HMB or α-HICA supplementation on training-induced changes in body composition

β-hydroxy-β-methylbutyrate (calcium: HMB-Ca and free acid: HMB-FA) and α-hydroxyisocaproic acid (α-HICA) are leucine metabolites that have been proposed to improve body composition and strength when combined with resistance exercise training (RET). In this double-blind randomized controlled pragmatic trial, we evaluated the effects of off-the-shelf supplements: α-HICA, HMB-FA and HMB-Ca, on RET-induced changes in body composition and performance. Forty men were blocked randomized to receive α-HICA (n = 10, fat-free mass [FFM] = 62.0 ± 7.1 kg), HMB-FA (n = 11, FFM = 62.7 ± 10.5 kg), HMB-Ca (n = 9, FFM = 65.6 ± 10.1 kg) or placebo (PLA; n = 10, FFM = 64.2 ± 5.7 kg). The training protocol consisted of a whole-body resistance training routine, thrice weekly for 8 weeks. Body composition was assessed by dual-energy x-ray absorptiometry (DXA) and total body water (TBW) by whole-body bioimpedance spectroscopy (BIS), both at baseline and at the end of weeks 4 and 8. Time-dependent changes were observed for increase in trunk FFM (p < 0.05). No statistically significant between-group or group-by-time interactions were observed. Supplementation with HMB (FA and Ca) or α-HICA failed to enhance body composition to a greater extent than placebo. We do not recommend these leucine metabolites for improving body composition changes with RET in young adult resistance trained men.

Effects of Alpha-hydroxy-isocaproic acid upon Body Composition in a Type I Diabetic Patient with Muscle Atrophy - A Case Study

Research involving dietary supplement interventions for sarcopenia and osteopenia in type 1 diabetes patients is scarce. Here we present a case study of a type 1 diabetic patient that was treated with supplemental alpha-hydroxy-isocaproic acid (α-HICA) for 120 days. Several measures of body composition by dual x-ray absorptiometry, blood markers, and maximum voluntary contraction parameters were assessed at baseline and after 120 days. The patient's baseline weight was 73.2 kg, which increased to 75.2 kg by the 120-day assessment. Salient mass distribution changes included increases of trunk fat mass (+0.4 kg), trunk fat free mass (+0.2 kg), total trunk mass (+0.2 kg), and a decrease of 8 percent in trunk fat mass contribution. Handgrip strength increased by 58.84 N, whereas isometric force in the leg press decreased by 347.15 N. Amelioration of BMD Z-scores from -0.7 to 0.5 and T-scores from -1.0 to -0.9 were noted. Importantly, full hematologic measures and weekly nutritional counselling assessments revealed no signs of adverse effects with α-HICA supplementation. Due to the imperative of maintaining FFM, strength and bone mass in these patients, additional research is necessary to confirm these promising results and to clarify whether leucine and/or one of its derivatives might be clinically useful.

Association between whey protein, regional fat mass, and strength in resistance-trained men: a cross-sectional study

The purpose of this study was to evaluate the association between whey protein supplementation, body composition, and muscle strength in resistance-trained individuals. Forty-nine healthy males, aged 18 to 35 years and were engaged in resistance training for at least 1 year, were assigned into 2 groups according to whey protein intake (whey - n = 26, age: 30.7 ± 7.4 years, body mass: 75.8 ± 9.0 kg; without whey: n = 23, age: 31.0 ± 7.4 years, body mass: 77.9 ± 9.3 kg). Using a cross-sectional design, a morning assessment of body fat mass (FM) (by dual-energy X-ray absorptiometry) and strength (using 1-repetition maximum for bench press and back squat) was performed. Nutritional assessment was performed by 3-day food records. Regarding nutritional habits, differences between total energy intake (kcal) and estimated energy requirements (kcal) were observed. Results, from raw data or controlling for energy intake, estimated energy requirements, or achieved percentage of energy requirements, showed that whey protein supplementation was inversely correlated with whole-body FM (R = -0.367 (p = 0.010); R = -0.317 (p = 0.049); R = -0.380 (p = 0.011); R = -0.321 (p = 0.047), respectively), trunk FM (R = -0.396 (p = 0.005), R = -0.367 (p = 0.022), R = -0.423 (p = 0.004), R = -0.369 (p = 0.021), respectively) and android FM (R = -0.381 (p = 0.007), R = -0.332 (p = 0.039), R = -0.383 (p = 0.010), R = -0.336 (p = 0.036), respectively). No correlations were found between muscle strength outcomes and whey protein supplementation. The present data suggest that whey protein ingestion has a positive association with whole-body and regional (trunk and android) FM.

Characterization and Comparison of Nutritional Intake between Preparatory and Competitive Phase of Highly Trained Athletes

Background and objective: For a high level athlete, it is essential to ensure optimal energy as well as macro- and micro-nutrient and fluid intakes, in order to improve their performance during training and competition. Protein intake should be 1.2⁻2.1 g/kg/d, whereas the requirements for carbohydrate and fat intakes should be >5g/kg/d and 20⁻35% of energy, respectively. The micronutrient and fluid intakes in athletes were compared to the Dietary Reference Intake (DRI) and European Food Safety Authority (EFSA) recommendations, respectively. This study aimed to characterize and compare the nutritional habits of athletes at the preparatory and competitive phase, and to test if their nutritional intakes were in accordance with the recommendations. Materials and methods: A total of 276 professional athletes were assessed. To evaluate their nutritional intake, the athletes completed a 7 days food record. Under reporting was defined using a ratio of energy intake to basal metabolic rate (BMR) of 1.1. Body composition was assessed using dual energy X-ray absorptiometry (DXA). Results: Almost half (49%) of the athletes from the final sample reported lower measured intakes of carbohydrates and 27% reported a higher consumption of proteins than what was recommended. In both the preparatory and competitive phases, the micronutrients with a higher mismatch between the actual and recommended intakes were vitamins D and E, magnesium, folate, calcium, and zinc for both sexes, and iron intake for females. A large proportion of athletes reported a lower water intake. Compared to the recommendations, males reported a higher intake of carbohydrates, lipids, vitamins E, calcium, and magnesium (p <0.05) in the competitive phase, while females reported a lower ingestion of water, vitamins A and D, and calcium (p <0.05) in the preparatory phase. Conclusions: Overall, in the preparatory and competitive phases of the season, athletes reported a macro- and micro-nutrient intake below the recommendations, especially in the female athletic population. Dietary intakes in athletes need to be optimized and adjusted to their requirements, according to sex and sport, so as to avoid compromising health and performance.

Energy Balance over One Athletic Season

INTRODUCTION

Magnitude and variation in energy balance (EB) components over an athletic season are largely unknown.

PURPOSE

We investigated the longitudinal changes in EB over one season and explored the association between EB variation and change in the main fat-free mass (FFM) components in highly trained athletes.

METHODS

Eighty athletes (54 males; handball, volleyball, basketball, triathlete, and swimming) were evaluated from the beginning of the season to the main competition stage. Resting and total energy expenditure (REE and TEE, respectively) were assessed by indirect calorimetry and doubly labeled water, respectively. Physical activity energy expenditure was calculated as TEE - 0.1 TEE - REE. Fat mass (FM), FFM, and bone mineral were evaluated with dual-energy x-ray absorptiometry; changed body energy stores were calculated as 1.0(ΔFFM/Δtime) + 9.5(ΔFM/Δtime). Total-body water (TBW) and its compartments were assessed through dilution techniques, and total-body protein was calculated from a four-compartment model, with body volume assessed by air displacement plethysmography.

RESULTS

Although a negative EB of -17.4 ± 72.7 kcal·d was observed (P < 0.05), EB varied widely among sports and across sex groups resulting in a net weight increase (0.7 ± 2.3 kg) that is attributable to significant changes in FFM (1.2 ± 1.6 kg) and FM (-0.7 ± 1.5 kg) (P < 0.05). EB was related with TBW and intracellular water (r = 0.354, r = 0.257, P < 0.05, respectively), regardless of sex, sports, and age.

CONCLUSIONS

The mean negative EB observed over the season resulted from the rate of FM use and FFM accretion, but with a large variation by sex and sports. TBW, but not total-body protein or mineral balance, explained the magnitude of EB, which means that athletes under a positive or a negative EB showed a TBW expansion or shrinkage, respectively, specifically within the cells, over one athletic season.

Long-term swimming training modifies acute immune cell response to a high-intensity session

PURPOSE

Long-term training influence on athletes' immune cell response to acute exercise has been poorly studied, despite the complexity of both chronic and acute adaptations induced by training. The purpose of the study is to study the influence of a 4-month swimming training cycle on the immune cell response to a high-intensity training session, during 24 h of recovery, considering sex, maturity, and age group.

METHODS

Forty-three swimmers (16 females, 14.4 ± 1.1 years; 27 males, 16.2 ± 2.0) performed a standardized high-intensity session, after the main competition of the first (M1), and second (M2) macrocycles. Blood samples were collected before (Pre), immediately after (Post), 2 h after (Post2h) and 24 h after (Post24h) exercise. Haemogram and lymphocytes subsets were assessed by an automatic cell counter and by flow cytometry, respectively. Subjects were grouped according to sex, competitive age groups, or pubertal Tanner stages. Results express the percentage of relative differences from Pre to Post, Post2h and Post24h. Upper respiratory symptoms (URS) and training load were quantified.

RESULTS

At M2, we observed smaller increases of leukocytes (M1: 14.0 ± 36.3/M2: 2.33 ± 23.0%) and neutrophils (M1: 57.1 ± 71.6/M2: 38.9 ± 49.9%) at Post; and less efficient recoveries of total lymphocytes (M1: - 22.0 ± 20.1/M2: - 30.0 ± 18.6%) and CD19⁺ (M1: 4.09 ± 31.1/M2: - 19.1 ± 24.4%) at Post2h. At Post2h, the increment of CD4⁺/CD8⁺ was smaller in youth (M1: 21.5 ± 16.0/M2: 9.23 ± 21.4%), and bigger in seniors (M1: 3.68 ± 9.21/M2: 23.2 ± 15.0%); and at Post24h late pubertal swimmers' CD16⁺56⁺ recovered less efficiently (M1: - 0.66 ± 34.6/M2: - 20.5 ± 34.2%).

CONCLUSIONS

The training cycle induced an attenuated immune change immediately after exercise and a less efficient recovery of total lymphocytes, involving an accentuated CD19⁺ decrease. The concomitant higher URS frequency suggests a potential immune depression and a longer interval of susceptibility to infection.

Compensatory Changes in Energy Balance Regulation over One Athletic Season

PURPOSE

Mechanisms in energy balance (EB) regulation may include compensatory changes in energy intake (EI) and metabolic adaption (MA), but information is unavailable in athletes who often change EB components. We aim to investigate EB regulation compensatory mechanisms over one athletic season.

METHODS

Fifty-seven athletes (39 males/18 females; handball, volleyball, basketball, triathlon, and swimming) were evaluated from the beginning to the competitive phase of the season. Resting and total energy expenditure (REE and TEE, respectively) were assessed by indirect calorimetry and doubly labeled water, respectively, and physical activity energy expenditure was determined as TEE - 0.1(TEE) - REE. Fat mass (FM) and fat-free mass (FFM) were evaluated by dual-energy x-ray absorptiometry and changed body energy stores was determined by 1.0(ΔFFM/Δtime) + 9.5(ΔFM/Δtime). EI was derived as TEE + EB. REE was predicted from baseline FFM, FM, sex, and sports. %MA was calculated as 100(measured REE/predicted REE-1) and MA (kcal) as %MA/100 multiplied by baseline measured REE. Average EI minus average physical activity energy expenditure was computed as a proxy of average energy availability, assuming that a constant nonexercise EE occurred over the season.

RESULTS

Body mass increased by 0.8 ± 2.5 kg (P < 0.05), but a large individual variability was found ranging from -6.1 to 5.2 kg. The TEE raise (16.8% ± 11.7%) was compensated by an increase EI change (16.3% ± 12.0%) for the whole group (P < 0.05). MA was found in triathletes, sparing 128 ± 168 kcal·d, and basketball players, dissipating 168 ± 205 kcal·d (P < 0.05). MA was associated (P < 0.05) with EB and energy availability (r = 0.356 and r = 0.0644, respectively).

CONCLUSION

TEE increased over the season without relevant mean changes in weight, suggesting that EI compensation likely occurred. The thrifty or spendthrift phenotypes observed among sports and the demanding workloads these athletes are exposed to highlight the need for sport-specific energy requirements.

Do Dynamic Fat and Fat-Free Mass Changes follow Theoretical Driven Rules in Athletes?

INTRODUCTION

Maximizing fat mass (FM) loss while preserving or increasing fat-free mass (FFM) is a central goal for athletic performance but the composition of body weight (BW) changes over time with training are largely unknown.

PURPOSE

We aimed to analyze FM and FFM contributions to BW changes and to test if these contributions follow established rules and predictions over one athletic season.

METHODS

Seventy athletes (42 men; handball, volleyball, basketball, triathlon, and swimming) were evaluated from the beginning to the competitive stage of the season and were empirically divided into those who lost (n = 20) or gained >1.5% BW (n = 50). FM and FFM were evaluated with a four-compartment model. Energy densities (ED) of 1.0 kcal·g for FFM and 9.5 kcal·g for FM were used to calculate ED/per kilogram BW change.

RESULTS

Athletes that lost >1.5% BW decreased FM by 1.7 ± 1.6 kg (P < 0.05), whereas FFM loss was nonsignificant (-0.7 ± 2.1 kg). Those who gained >1.5% BW increased FFM by 2.3 ± 2.1 kg (P < 0.05) with nonsignificant FM gains (0.4 ± 2.2 kg). The proportion of BW change as FM for those who lost or gained BW was 90% (ED: 8678 ± 2147 kcal·kg) and 5% (ED: 1449 ± 1525 kcal·kg), respectively (P < 0.001). FFM changes from Forbes Curve were inversely related to observed changes (r = -0.64; r = -0.81, respectively for those who lost or gained BW).

CONCLUSIONS

Athletes that lost BW used 90% of the energy from FM while in those gaining BW, 95% was directed to FFM. When BW is lost, dynamic changes in its composition do not follow established rules and predictions used for lean or overweight/obese nonathletic populations.

Comparison of immunohematological profile between endurance- and power-oriented elite athletes

There is general perception that elite athletes are highly susceptible to changes in immunohematological profile. The objective of this study was to compare immunohematological parameters of elite athletes of different aerobic and muscular strength sports and analyze changes over 2 months. Sixteen judoists and 14 swimmers were evaluated 2 months before (M1) and immediately prior to competition (M2). Hemogram and lymphocytes subpopulations were assessed with automatic counter and flow cytometry, respectively. Judoists had higher neutrophils and lower monocytes and eosinophils percentages than swimmers at M1 and M2. At M2 judoists had lower red blood cells (RBC), hemoglobin, and hematocrit than swimmers. At M2 judoists' hematocrit and CD16 decreased while swimmers' hemoglobin and hematocrit increased. In conclusion, neither sports characteristics nor intense training seem to displace the athletes' immunohematological profile out of the clinical range, despite the possibility of occurrence of microlesions that may stimulate production of leukocytes and reduction of RBC in judoists.

Accuracy of a combined heart rate and motion sensor for assessing energy expenditure in free-living adults during a double-blind crossover caffeine trial using doubly labeled water as the reference method

BACKGROUND/OBJECTIVES

A combined heart rate (HR) and motion sensor (Actiheart) has been proposed as an accurate method for assessing total energy expenditure (TEE) and physical activity energy expenditure (PAEE). However, the extent to which factors such as caffeine may affect the accuracy by which the estimated HR-related PAEE contribution will affect TEE and PAEE estimates is unknown. Therefore, we examined the validity of Actiheart in estimating TEE and PAEE in free-living adults under a caffeine trial compared with doubly labeled water (DLW) as reference criterion.

SUBJECTS/METHODS

Using a double-blind crossover trial (Clinicaltrials.gov ID: #NCT01477294) with two conditions (4-day each with a 3-day-washout period), randomly ordered as caffeine (5 mg/kg per day) and placebo (malt-dextrine) intake, TEE was measured by DLW in 17 physically active men (20-38 years) who were non-caffeine users. In each condition, resting energy expenditure (REE) was assessed by indirect calorimetry and PAEE was calculated as (TEE-(REE+0.1 TEE)). Simultaneously, PAEE and TEE were estimated by Actiheart using an individual calibration (ACC+HRstep).

RESULTS

Under caffeine, ACC+HRstep explained 76 and 64% of TEE and PAEE from DLW, respectively; corresponding results for the placebo condition were 82 and 66%. No mean bias was found between ACC+HRstep and DLW for TEE (caffeine:-468 kJ per day; placebo:-407 kJ per day), although PAEE was slightly underestimated (caffeine:-856 kJ per day; placebo:-1147 kJ per day). Similar limits of agreement were observed in both conditions ranging from -2066 to 3002 and from -3488 to 1776 kJ per day for TEE and PAEE, respectively.

CONCLUSIONS

Regardless of caffeine intake, the combined HR and motion sensor is valid for estimating free-living energy expenditure in a group of healthy men but is less accurate for an individual assessment.

Sex-based effects on immune changes induced by a maximal incremental exercise test in well-trained swimmers

Studies examining the immune response to acute intensive swimming have shown increased leukocytosis and lymphocyte populations. However, studies concerning mucosal immunity and sex differences remain controversial. The objective of the study was to examine sex differences on the immune response to maximal incremental swimming exercise in well trained swimmers. Participants (11 females, controlled for menstrual cycle phase effects; 10 males) performed a maximal incremental 7x200 m front crawl set. Fingertip capillary blood samples were obtained after each 200 m swim for lactate assessment. Venous blood and saliva samples were collected before and 5 minutes after the swimming test to determine total numbers of leukocytes, lymphocytes and subpopulations, and serum and salivary immunoglobulin A (IgA) levels. IgA secretion rate was calculated. Menstrual cycle phase did not influence the immune response to exercise. As for sex differences, exercise induced an increase in leukocytes, total lymphocytes, CD3(+), CD4(+), CD8(+), and CD16(+)/56(+) in males. In females, only leukocytosis, of a lower magnitude than was observed in males, occurred. CD19(+) increased and CD4(+)/CD8(+) ratio decreased in both groups following exercise whilst IgA, SIgA concentrations, and srIgA did not change. Both males and females finished the incremental exercise very close to the targeted race velocity, attaining peak blood lactate concentrations of 14.6±2.25 and 10.4±1.99 mmol.L(-1), respectively. The effect of a maximal incremental swimming task on immunity is sex dependent and more noticeable in men. Males, as a consequence of higher levels of immunosurveillance may therefore be at a lower risk of infection than females. Key PointsMaximal exercise induces an immune response.This study investigated the influence of sex over the leukocytes subpopulations and mucosal immune responses to maximal swimming.Male swimmers showed a stronger increase of T helper, T cytotoxic and NK lymphocytes than females, suggesting they may be at a lower risk of infection, due to a higher immunosurveillance.Mucosal immunity remained unchanged in both sexes.

Increases in intracellular water explain strength and power improvements over a season

Changes in body components occur over a season, but their impact on performance is still unclear. We aimed to analyze the relationship between changes in leg strength and jump performance with body composition over a season in highly trained athletes. Measures from the beginning to the main competitive periods of a season were obtained in 40 male and 23 female basketball, handball and volleyball players (20±5 years) for fat (FM) and fat-free mass (FFM) estimated by DXA. Total body water (TBW) and extracellular water (ECW) were assessed by deuterium and bromide dilution, respectively, and intracellular water (ICW) was calculated as TBW minus ECW. Maximal strength was determined by the leg press, while jumping height was assessed with squat (SJ) and countermovement (CMJ) jumps. Significant improvements in strength (12.5±20.8%) and jumping height (SJ:8.3±13.9%; CMJ:6.3±8.5%) were found. FFM, TBW and ECW significantly increased (3.0±2.7%; 1.7±5.5%; 3.0±8.6%, respectively), while %FM decreased (-4.5±9.1%) and no changes were observed in ICW (1.2±9.7%). Among body composition changes only ICW was associated with performance even adjusted for gender, age, season length and sport (strength: β=71.209, p=0.012; SJ: β=0.311, p=0.049; CMJ: β=0.366, p=0.018). Body composition, strength and jumping height improved over a season and ICW was the main predictor of performance in national level players.

Reference values for body composition and anthropometric measurements in athletes

BACKGROUND

Despite the importance of body composition in athletes, reference sex- and sport-specific body composition data are lacking. We aim to develop reference values for body composition and anthropometric measurements in athletes.

METHODS

Body weight and height were measured in 898 athletes (264 female, 634 male), anthropometric variables were assessed in 798 athletes (240 female and 558 male), and in 481 athletes (142 female and 339 male) with dual-energy X-ray absorptiometry (DXA). A total of 21 different sports were represented. Reference percentiles (5th, 25th, 50th, 75th, and 95th) were calculated for each measured value, stratified by sex and sport. Because sample sizes within a sport were often very low for some outcomes, the percentiles were estimated using a parametric, empirical Bayesian framework that allowed sharing information across sports.

RESULTS

We derived sex- and sport-specific reference percentiles for the following DXA outcomes: total (whole body scan) and regional (subtotal, trunk, and appendicular) bone mineral content, bone mineral density, absolute and percentage fat mass, fat-free mass, and lean soft tissue. Additionally, we derived reference percentiles for height-normalized indexes by dividing fat mass, fat-free mass, and appendicular lean soft tissue by height squared. We also derived sex- and sport-specific reference percentiles for the following anthropometry outcomes: weight, height, body mass index, sum of skinfold thicknesses (7 skinfolds, appendicular skinfolds, trunk skinfolds, arm skinfolds, and leg skinfolds), circumferences (hip, arm, midthigh, calf, and abdominal circumferences), and muscle circumferences (arm, thigh, and calf muscle circumferences).

CONCLUSIONS

These reference percentiles will be a helpful tool for sports professionals, in both clinical and field settings, for body composition assessment in athletes.

Association of basketball season with body composition in elite junior players

AIM

Body composition changes among elite athletes may influence competitive performance. This study aimed to characterize the body composition changes at the molecular, cellular, tissue, and whole-body level of analysis in elite junior basketball players during the course of a season.

METHODS

Twelve males and 11 females (16 to 17 years) were evaluated. Dual-energy X-ray absorptiometry (DXA) was used to assess bone mineral (Mo) and lean-soft tissue (LST). Total-body water (TBW) and extracellular water (ECW) were assessed using isotope dilution techniques, and extracellular (ECF) and intracellular fluids (ICF) were calculated. Fat mass (FM) and fat-free mass (FFM) were assessed with a four-compartment model. Body cell mass was calculated (LST - (ECF + ECS)). Skeletal muscle (SM) was estimated using appendicular LST (ALST) as: (1.19 x ALST) - 1.65. At the whole-body level, weight, sum of 7 skinfolds, and muscle circumferences (Mc) were measured. The handgrip and the countermovement jump tests were used for performance assessment.

RESULTS

Males increased FFM (4.4±2.3%), TBW (3.5±4.6%), SM (4.5±2.3%), and arm (3.4±2.7%) and thigh (3.8±3%) Mc. Females increased SM (5.9±4.6%) and arm (3.6±3.8%) and thigh (4±5.2%) Mc and decreased ICF (-9.7±13.6%). FFM components differed from the established values based on cadaver analysis. Both genders increased their performance and associations were found between changes in molecular and whole-body components with performance.

CONCLUSION

In conclusion the season was associated with an improved body composition profile in males and few changes in females.

Total energy expenditure assessment in elite junior basketball players: a validation study using doubly labeled water

An accurate assessment of total energy expenditure (TEE) during a competitive season is required. We aimed to validate TEE estimated by self-reported energy intake (EI) and the dietary reference intake (DRI) method in 19 elite basketball players (aged 16-18 years) using doubly labeled water (DLW) as the reference method. The DRI models and EI from dietary records over a 7-day period were simultaneously assessed for TEE estimation. Resting energy expenditure was assessed by indirect calorimetry. Fat and fat-free mass (FFM) were determined by a 4-compartment model (body volume by air displacement plethysmography, bone mineral by DXA, and water by deuterium dilution). Fat and FFM ranged from 4 to 19 kg and from 47 to 81 kg, respectively. The physical activity level ranged from 2.2 to 3.7 with a mean value of 2.8 ± 0.4. Total energy expenditure from DLW (17,598 ± 3,298 kJ·d) was significantly underestimated by EI (11,274 ± 2,567 kJ·d), whereas no differences were found using DRI (17,008 ± 3,206 kJ·d). The EI and DRI methods explained TEE from DLW by 34% (p = 0.057) and 44% (p = 0.002), respectively, and wide limits of agreement were observed. Our findings suggested that EI is not a valid tool for TEE assessment. The DRI method may be valid at a group level but inaccurate for estimating individual TEE in young players during a demanding competitive season period.

Validity of a combined heart rate and motion sensor for the measurement of free-living energy expenditure in very active individuals

OBJECTIVES

The correct assessment of energy expenditure in very active individuals is important to ensure that dietary energy intake is sufficient. We aimed to validate a combined heart rate (HR) and motion sensor in estimating total (TEE) and activity energy expenditure (AEE) in males and females with high physical activity levels.

DESIGN

Cross-sectional.

METHODS

Doubly-labelled water (DLW) was used to assess 7-day TEE in 12 male and female elite junior basketball players, aged 16-17 years. Resting energy expenditure (REE) was assessed with indirect calorimetry and AEE was calculated (AEE=TEE-RMR-0.1×TEE). Simultaneously, TEE and AEE were measured by combined HR and motion sensing. Individual HR calibration was performed with step-test. TEE and AEE were estimated from accelerometry and HR with individual (ACC+HRstep) and group calibration (ACC+HRgroup).

RESULTS

No mean differences were found between TEE and AEE from the ACC+HRstep and ACC+HRgroup with DLW. TEE values (kJ/day) from ACC+HRgroup and ACC+HRstep explained TEE from DLW by ∼60% and 53%, respectively whereas AEE (kJ/day) estimated by ACC+HRgroup and ACC+HRstep explained 53% and 41% of the variability of AEE from the reference method. Concordance correlation coefficients for TEE and AEE using ACC+HRgroup were 0.74 and 0.69, correspondingly while for ACC+HRstep values of 0.69 and 0.45 were found. Large limits of agreement were found for TEE and AEE using both ACC+HRgroup and ACC+HRstep.

CONCLUSIONS

ACC+HR models are a valid alternative to estimate TEE but not AEE in a group of highly active individuals however the considerable rate of equipment failure (∼50%) limits its usefulness.

Caffeine intake, short bouts of physical activity, and energy expenditure: a double-blind randomized crossover trial

PA energy expenditure (PAEE) is the most variable component of Total Energy Expenditure (TEE) and largely due to the balance of sedentary time (SedT) and low intensity physical activity (LIPA). There has been an emergence for seeking an understanding of factors which determine variations in SedT, LIPA, and PAEE. Sedentary behavior and physical activity are relatively resistant to change by experimental dietary treatments and significant body weight changes. Although caffeine (Caf) is by far the most heavily used nutritional agent ingested to promote a sense of vigor/alertness, it is still unknown if Caf is effective in increasing PAEE and physical activity. The aim of the study was to test the hypothesis that 2 daily doses of Caf (as a capsule to blind the treatment and divided equally during breakfast and lunch) increase PAEE and TEE, and it would do so through increasing the frequent and brief bouts of physical activity (~1-5 min long) through the day as measured by accelerometry. In 21 low Caf users (<100 mg day(-1)), we used a double-blind crossover trial (ClinicalTrials.govID;NCT01477294) with two conditions (4-day each with a 3-day washout period) randomly ordered as 5 mg kg(-1) day(-1) of Caf and maltodextrin as placebo (Plc). Resting energy expenditure (REE) by indirect calorimetry, total energy expenditure (TEE) from doubly labeled water, PAEE calculated as TEE-(REE+0.1TEE), and accelerometry measurements of both LIPA and MVPA were not different between conditions. However, regardless of caffeine or placebo, there were several significant relationships between brief bouts of LIPA and MVPA with PAEE. In conclusion, this double-blind study found that low and moderate-vigorous activity as well as the total volume of PAEE in free-living conditions is resistant to dietary caffeine intake that was equivalent to 5 cups of espresso or 7 cups of tea.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01477294.

Total body water and its compartments are not affected by ingesting a moderate dose of caffeine in healthy young adult males

Acute and chronic caffeine intakes have no impact on hydration status (R.J. Maughan and J. Griffin, J. Hum. Nutr. Diet. 16(6): 411-420, 2003), although no research has been conducted to analyze the effects using dilution techniques on total-body water (TBW) and its compartments. Therefore, the aim of this study was to investigate the effects of a moderate dose of caffeine on TBW, extracellular water (ECW), and intracellular water (ICW) during a 4-day period in active males. Thirty men, nonsmokers and low caffeine users (<100 mg·day(-1)), aged 20-39 years, participated in this double-blind, randomized, crossover trial (ClinicalTrials.gov: No. NCT01477294). The study included 2 conditions (5 mg·kg(-1)·day(-1) of caffeine and placebo (malt-dextrin)) of 4 days each, with a 3-day washout period. TBW and ECW were assessed by deuterium oxide and sodium bromide dilution, respectively, whereas ICW was calculated as TBW minus ECW. Body composition was assessed by dual-energy X-ray absorptiometry. Physical activity (PA) was assessed by accelerometry and water intake was assessed by dietary records. Repeated-measures analysis of variance (ANOVA) was used to test main effects. No changes in TBW, ECW, or ICW and no interaction between the randomly assigned order of treatment and time were observed (p > 0.05). TBW, ECW, and ICW were unrelated to fat-free mass, water ingestion, and PA (p > 0.05). These findings indicate that a moderate caffeine dose, equivalent to approximately 5 espresso cups of coffee or 7 servings of tea, does not alter TBW and fluid distribution in healthy men, regardless of body composition, PA, or daily water ingestion.

A moderate dose of caffeine ingestion does not change energy expenditure but decreases sleep time in physically active males: a double-blind randomized controlled trial

Research on the effect of caffeine on energy expenditure (EE), physical activity (PA), and total sleep time (TST) during free-living conditions using objective measures is scarce. We aimed to determine the impact of a moderate dose of caffeine on TST, resting EE (REE), physical activity EE (PAEE), total EE (TEE), and daily time spent in sedentary, light, moderate, and vigorous intensity activities in a 4-day period and the acute effects on heart rate (HR) and EE in physically active males. Using a double-blind crossover trial (ClinicalTrials.gov ID: NCT01477294) with two conditions (4 days each with 3-day washout) randomly ordered as caffeine (5 mg/kg of body mass/day) and placebo (maltodextrin) administered twice per day (2.5 mg/kg), 30 nonsmoker males, low-caffeine users (<100 mg/day), aged 20-39, were followed. Body composition was assessed by dual-energy X-ray absorptiometry. PA was assessed by accelerometry, while a combined HR and movement sensor estimated EE and HR on the second hour after the first administration dose. REE was assessed by indirect calorimetry, and PAEE was calculated as [TEE - (REE + 0.1TEE)]. TST and daily food records were obtained. Repeated measures ANOVA and ANCOVA were used. After a 4-day period, adjusting for fat-free mass, PAEE, and REE, TST was reduced (p = 0.022) under caffeine intake, while no differences were found between conditions for REE, PAEE, TEE, and PA patterns. Also, no acute effects on HR and EE were found between conditions. Though a large individual variability was observed, our findings revealed no acute or long-term effects of caffeine on EE and PA but decreased TST during free-living conditions in healthy males.

Is bioelectrical impedance spectroscopy accurate in estimating total body water and its compartments in elite athletes?

BACKGROUND

Bioelectrical impedance spectroscopy (BIS) provides an affordable assessment of the body's various water compartments: total body water (TBW), extracellular water (ECW) and intracellular water (ICW). However, little is known of its validity in athletes.

AIM

To validate TBW, ECW and ICW by BIS in elite male and female Portuguese athletes using dilution techniques (i.e. deuterium and bromide dilution) as criterion methods.

SUBJECTS AND METHODS

Sixty-two athletes (18.5 ± 4.1 years) had TBW, ECW and ICW assessed by BIS during their respective pre-season.

RESULTS

BIS significantly under-estimated TBW by 1.0 ± 1.7 kg and ICW by 0.9 ± 1.9 kg in relation to the criterion methods, with no differences observed for ECW. The values for the concordance correlation coefficient were 0.98 for TBW and ECW and 0.95 for ICW. Bland-Altman analyses revealed no bias for the various water compartments, with the 95% confidence intervals ranging from - 4.8 to 2.6 kg for TBW, - 1.5 to 1.6 kg for ECW and - 4.5 to 2.7 kg for ICW.

CONCLUSIONS

Overall, these findings demonstrate the validity of BIS as a valid tool in the assessment of TBW and its compartments in both male and female athletes.