Comparison of series and parallel reactance to identify changes in intracellular water in response to physical training in athletes during a sports season.

OBJECTIVE: Cross-sectional evidence has demonstrated that parallel reactance obtained by bioelectrical impedance analysis (BIA) may be an alternative to the regularly used series of measurements to predict intracellular water (ICW) in athletes. However, we are not aware of any studies that have determined the predictive role or compared the effectiveness of both series and parallel reactance for tracking ICW changes during an athletic season. The main aim of this study was to determine the predictive role and compare both series and parallel reactance (Xc) in tracking ICW during an athletic season. RESEARCH METHODS AND PROCEDURES: This longitudinal study analyzed 108 athletes in the preparatory and competitive periods. Using dilution techniques, total body water (TBW) and extracellular water (ECW) were determined and ICW was calculated. Resistance (R), Xc, and impedance (Z) standardized for height were obtained through BIA spectroscopy using a frequency of 50kHz in a series array and then mathematically transformed in a parallel array. RESULTS: Multiple regression analyses showed that only changes in parallel Xc and capacitance (CAP) (P < 0.05) were predictors of delta ICW during the sports season. In contracts, this was not the case for Xcs. Both changes in R and Z, series and parallel, predicted similarly the changes in ECW and TBW (P < 0.05) in athletes. CONCLUSION: Our findings highlight the potential of parallel BIA values to detect changes in body water compartments over a competitive season. These data provide preliminary evidence that changes in parallel Xc/H, and ultimately CAP, represent valid markers of alterations in cell volume during a sports season.

H2OAthletes study protocol: effects of hydration changes on neuromuscular function in athletes.

We aim to understand the effects of hydration changes on athletes' neuromuscular performance, on body water compartments, fat-free mass hydration and hydration biomarkers and to test the effects of the intervention on the response of acute dehydration in the hydration indexes. The H2OAthletes study (clinicaltrials.gov ID: NCT05380089) is a randomised controlled trial in thirty-eight national/international athletes of both sexes with low total water intake (WI) (i.e. < 35·0 ml/kg/d). In the intervention, participants will be randomly assigned to the control (CG, n 19) or experimental group (EG, n 19). During the 4-day intervention, WI will be maintained in the CG and increased in the EG (i.e. > 45·0 ml/kg/d). Exercise-induced dehydration protocols with thermal stress will be performed before and after the intervention. Neuromuscular performance (knee extension/flexion with electromyography and handgrip), hydration indexes (serum, urine and saliva osmolality), body water compartments and water flux (dilution techniques, body composition (four-compartment model) and biochemical parameters (vasopressin and Na) will be evaluated. This trial will provide novel evidence about the effects of hydration changes on neuromuscular function and hydration status in athletes with low WI, providing useful information for athletes and sports-related professionals aiming to improve athletic performance.

Interindividual variability in energy intake and expenditure during a weight loss intervention.

INTRODUCTION: Behavioral compensations may occur as a response to a negative energy balance. The aim of this study was to explore the associations between changes in energy intake (EI) and changes in physical activity (PA, min/day; kcal/d) as a response to a weight loss (WL) intervention and to understand if interindividual differences occur in EI and energy expenditure (EE). METHODS: Eighty-one participants [mean (SD): age = 42.8 (9.4)y, BMI = 31.2 (4.4)kg/m2, 37% females] divided in intervention (IG, n = 43) and control group (CG, n = 38) were included. The IG underwent a moderate energy restriction (300-500 kcal/d). EI was measured through the intake-balance method. Non-exercise PA (NEPA) and exercise (through logbook) were assessed by accelerometery. The EE in NEPA (NEAT) and in exercise (EiEE) was calculated by applying the Freedson Combination'98 algorithm over the time spent in these activities. Pearson correlations were performed in IG to examine associations between EE components, EI and body composition. To understand if interindividual differences were observed, the SD of individual response (SDIR) and the smallest worthwhile change (SWC, SDbaselineCG×0.2) were calculated. RESULTS: Changes in EI [Δ EI, (kcal/d)] was negatively associated with Δ exercise (min/d:r = -0.413, p = 0.045; %:r = -0.846, p = 0.008) and with Δ EiEE (kcal/d:r = -0.488, p = 0.016; %:r = -0.859, p = 0.006). A negative correlation was found between Δ sedentary time and Δ NEPA (min/d:r = -0.622, p = 0.002; %:r = -0.487, p = 0.018). An interindividual variability was found for EI(SDIR = 151.6, SWC = 72.3) and EE (SDIR = 165, SWC = 134). CONCLUSIONS: Decreases in EI were not associated to compensatory responses such as decreases in PA and/or increases in sedentary time. Interindividual variability was found for EI and EE. Nevertheless, behavioral compensations and the interindividual variability should be considered when implementing WL interventions, to increase the likelihood of achieving sustainable results. (clinicaltrials.gov ID: NCT03031951).

Prediction of body water compartments by raw bioelectrical impedance parameters in athletes: Comparison between series and parallel measurements.

BACKGROUND: The aim of this study was to determine the predictive role of series and parallel bioelectrical impedance-derived parameters in predicting total body (TBW), intracellular (ICW), and extracellular water (ECW) in athletes. METHODS: This cross-sectional study analyzed 134 male (21.33 ± 5.11 years) and 64 female (20.45 ± 5.46 years) athletes. Using dilution techniques, TBW and ECW were determined while ICW was the difference between both. Raw and standardized for height (/H) bioelectrical resistance (R), reactance (Xc), and impedance (Z) values were obtained using a phase-sensitive device at a single frequency in a series array (s). These were mathematically transformed in a parallel array (p) and capacitance (CAP). Fat-free mass (FFM) was assessed by dual-energy X-ray absorptiometry. RESULTS: Multiple regressions adjusted for age and FFM show that R/Hs, Z/Hs, R/Hp, and Z/Hp were significant predictors of TBW (p < 0.001 in females and males). While Xc/Hs did not predict ICW, Xc/Hp was a predictor (p < 0.001 in females and Males). In females, R/H and Z/H predicted similarly TBW, ICW, and ECW. In males, R/Hs was considered a better predictor than R/Hp for TBW and ICW, and the Xc/Hp was considered the best predictor for ICW. Another significant predictor of ICW was CAP (p < 0.001 in females and males). CONCLUSION: This study highlights the potential value of parallel bioelectrical impedance values to identify fluid compartments in athletes as an alternative to the regularly used series measurements. Moreover, this study supports Xc in parallel, and ultimately CAP, as valid indicators of cell volume.

Plant Glucosinolate Content and Host-Plant Preference and Suitability in the Small White Butterfly (Lepidoptera: Pieridae) and Comparison with Another Specialist Lepidopteran.

Glucosinolates are used in host-plant recognition by insects specialized on Brassicaceae, such as Pieris rapae L. (Lepidoptera: Pieridae). This research investigated the association between P. rapae oviposition and larval survival and host-plant glucosinolate content using 17 plant species in which glucosinolate content had previously been determined. Two-choice oviposition tests (comparing each plant species to Arabidopsis thaliana L.) and larval survival experiments showed that indolic glucosinolate content had a positive effect on oviposition preference and larval survival in P. rapae. In the host plants tested, the effects of indolic glucosinolates on oviposition preference and of glucosinolate complexity index and aliphatic glucosinolates without sulfur-containing side chains on total oviposition were smaller on P. rapae than on Plutella xylostella L. (Lepidoptera: Plutellidae), another lepidopteran specialized on glucosinolate-containing plants. This study suggests that high indolic glucosinolate content could make crop plants more susceptible to both P. rapae and P. xylostella, but this effect seems to be greater for P. xylostella. Additionally, as some differences in oviposition and larval survival between P. rapae and P. xylostella occurred in some individual plants, it cannot be concluded that bottom-up factors are always similar in these two specialist insects.

Athletes with different habitual fluid intakes differ in hydration status but not in body water compartments.

Physiological differences have been reported between individuals who have habitual low (LOW) and high (HIGH) water intake (WI). The aims of this study were to explore body water compartments, hydration status, and fat-free mass (FFM) hydration of elite athletes exposed to different habitual WI. A total of 68 athletes (20.6 ± 5.3 years, 23 females) participated in this observational cross-sectional study. Total WI was assessed by seven-day food diaries and through WI, athletes were categorized as HIGH (n = 28, WI≥40.0 mL/kg/d) and LOW (n = 40, WI≤35.0 mL/kg/d). Total body water (TBW) and extracellular water (ECW) were determined by dilution techniques and intracellular water (ICW) as TBW-ECW. Hydration status was assessed by urine-specific gravity (USG) using a refractometer. Fat (FM) and FFM were assessed by dual-energy X-ray absorptiometry (DXA). The FFM hydration was calculated by TBW/FFM. The USG was statistically different between groups for females (LOW: 1.024 ± 0.003; HIGH: 1.015 ± 0.006; p = 0.005) and males (LOW: 1.024 ± 0.002; HIGH: 1.018 ± 0.005; p < 0.001). No differences between groups were detected in body water compartments and FFM hydration in both sexes (p > 0.05). Multiple regression showed that WI remains a predictor of USG regardless of FFM, age, and sex (ß = -0.0004, p < 0.01). We concluded that LOW athletes were classified as dehydrated through USG although their water compartments were not different from HIGH athletes. These results suggest that LOW athletes may expectedly maintain the body water compartments' homeostasis through endocrine mechanisms. Interventions should be taken to encourage athletes to have sufficient WI to maintain optimal hydration.

Between-devices agreement in obtaining raw bioelectrical parameters after a lifestyle intervention targeting weight loss in former athletes.

It is unclear if different bioelectrical impedance (BI) devices provide similar results regarding raw parameters [Resistance (R), Reactance (Xc), Phase Angle (PhA), and Impedance (Z)] for the same population/individual undergoing a weight loss intervention. The aim was to evaluate the cross-sectional and longitudinal agreement of raw data obtained by two BI devices in former athletes with overweight/obesity. Fifty-nine participants [mean (SD): 43.5 (9.2) years, 30.5 (4.0) kg/m2, 42% females] were included. All the assessments were performed before and after a 4-months lifestyle intervention targeting weight loss (WL). BI parameters were assessed at 50 kHz by two devices: a BI spectroscopy (Xitron Technologies, 4200B, San Diego, USA) and a phase-sensitive single-frequency device (BIA 101 AKERN, Florence, Italy). Cross-sectionally, BIS provided lower mean values for all parameters (0.4% for R, 1.6% for Xc, 1.0% for PhA and 0.4% for Z, p <0.001) compared to SF-BIA. In individuals with a WL≥2.5% (n =18), no longitudinal differences were found in any of the raw parameters between devices (p≥0.128) and there was no proportional bias (p≥0.408). Despite small baseline differences in raw BI parameters, both devices agreed in tracking changes over time at the group level but interpretation should be careful at the individual level.

Effects of a 4-month active weight loss phase followed by weight loss maintenance on adaptive thermogenesis in resting energy expenditure in former elite athletes.

PURPOSE: Despite adaptive thermogenesis (AT) being studied as a barrier to weight loss (WL), few studies assessed AT in the resting energy expenditure (REE) compartment after WL maintenance. The aim of this study was twofold: (1) to understand if AT occurs after a moderate WL and if AT persists after a period of WL maintenance; and (2) if AT is associated with changes in body composition, hormones and energy intake (EI). METHODS: Ninety-four participants [mean (SD); BMI, 31.1(4.3)kg/m2; 43.0(9.4)y; 34% female] were randomized to intervention (IG, n = 49) or control groups (CG, n = 45). Subjects underwent a 1-year lifestyle intervention, divided in 4 months of an active WL followed by 8 months of WL maintenance. Fat mass (FM) and fat-free mass (FFM) were measured by dual-energy X-ray absorptiometry and REE by indirect calorimetry. Predicted REE (pREE) was estimated through a model using FM, FFM. EI was measured by the "intake-balance" method. RESULTS: For the IG, the weight and FM losses were - 4.8 (4.9) and - 11.3 (10.8)%, respectively (p < 0.001). A time-group interaction was found between groups for AT. After WL, the IG showed an AT of -85(29) kcal.d-1 (p < 0.001), and remained significant after 1 year [AT = - 72(31)kcal.d-1, p = 0.031]. Participants with higher degrees of restriction were those with an increased energy conservation (R = - 0.325, p = 0.036 and R = - 0.308, p = 0.047, respectively). No associations were found between diet adherence and AT. Following a sub-analysis in the IG, the group with a higher energy conservation showed a lower WL and fat loss and a higher initial EI. CONCLUSION: AT in REE occurred after a moderate WL and remained significant after WL maintenance. More studies are needed to better clarify the mechanisms underlying the large variability observed in AT and providing an accurate methodological approach to avoid overstatements. Future studies on AT should consider not only changes in FM and FFM but also the FFM composition.

Energy Availability Over One Athletic Season: An Observational Study Among Athletes From Different Sports.

During the athletic season, changes in body composition occur due to fluctuations in energy expenditure and energy intake. Literature regarding changes of energy availability (EA) is still scarce. The aim was to estimate EA of athletes from nonweight and weight-sensitive sports during the athletic season (i.e., preparatory and competitive phase). Eighty-eight athletes (19.1 ± 4.2 years, 21.8 ± 2.0 kg/m2, 27% females, self-reported eumenorrheic) from five sports (basketball [n = 29]; handball [n = 7]; volleyball [n = 9]; swimming [n = 18]; and triathlon [n = 25]) were included in this observational study. Energy intake and exercise energy expenditure were measured through doubly labeled water (over 7 days and considering neutral energy balance) and metabolic equivalents of tasks, respectively. Fat-free mass (FFM) was assessed through a four-compartment model. EA was calculated as EA = (energy intake - exercise energy expenditure)/FFM. Linear mixed models, adjusted for sex, were performed to assess EA for the impact of time by sport interaction. Among all sports, EA increased over the season: basketball, estimated mean (SE): 7.2 (1.5) kcal/kg FFM, p < .001; handball, 14.8 (2.9) kcal/kg FFM, p < .001; volleyball, 7.9 (2.8) kcal/kg FFM, p = .006; swimming, 8.7 (2.0) kcal/kg FFM, p < .001; and triathlon, 9.6 (2.0) kcal/kg FFM, p < .001. Eleven athletes (12.5%) had clinical low EA at the preparatory phase and none during the competitive phase. During both assessments, triathletes' EA was below optimal, being lower than basketballers (p < .001), volleyballers (p < .05), and swimmers (p < .001). Although EA increased in all sports, triathlon's EA was below optimal during both assessments. Risk of low EA might be seasonal and resolved throughout the season, with higher risk during the preparatory phase. However, in weight-sensitive sports, namely triathlon, low EA is still present.

Breaking of Sitting Time Prevents Lower Leg Swelling-Comparison among Sit, Stand and Intermittent (Sit-to-Stand Transitions) Conditions.

BACKGROUND: Sitting or standing during prolonged periods is related to leg swelling. It is unknown if interrupting sedentary behavior can attenuate lower leg swelling. We aimed to examine if adding sit-to-stand transitions prevents lower leg swelling as compared with uninterrupted motionless standing and sitting, using localized bioelectrical impedance raw parameters. METHODS: Twenty adults participated in this crossover randomized controlled trial and acted out three conditions: (1) uninterrupted, motionless standing; (2) uninterrupted motionless sitting; (3) sit-to-stand transitions (1 min sitting followed by 1 min standing). Localized resistance (R), reactance (Xc), impedance (Z) and phase angle (PhA) were assessed at baseline, at 10 min and at 20 min for each condition. RESULTS: For sitting and standing conditions, R and Xc values decreased after 10 and 20 min. Uninterrupted sitting resulted in the highest decrease in R (ΔSit - ΔStand = -9.5 Ω (4.0), p = 0.019; ΔSit - ΔInt = -11.6 Ω (4.0), p = 0.005). For standardized R (R/knee height), sitting was the condition with a greater decrease (ΔSit - ΔStand = -30.5 Ω/m (13.4), p = 0.025; ΔSit - ΔInt = -35.0 Ω/m (13.5), p = 0.011). CONCLUSIONS: Interrupting sedentary behavior by changing from sit to stand position during short periods may be effective at preventing leg swelling.

Plant-Insect Interactions.

The central part of the study of plant-insect interactions comes from our quest for knowledge on why and how these interactions occur [...].

Changes in food reward and intuitive eating after weight loss and maintenance in former athletes with overweight or obesity.

OBJECTIVE: This study aimed to explore the following: 1) the impact of Champ4Life's intervention on intuitive eating and food reward; and 2) associations between changes in eating behavior and changes in body composition. METHODS: A total of 94 former athletes (mean [SD], BMI = 31.1 [4.3] kg/m2 , age = 43.0 [9.4] years, 34% female) assigned to intervention (n = 49) and control groups (n = 45) underwent 4 months of active weight loss (WL) followed by 8 months of WL maintenance. Intuitive eating and food reward were assessed by the Intuitive Eating Scale and the Leeds Food Preference Questionnaire, respectively. RESULTS: The WL was -4.8% (4.9%) and 0.3% (2.6%) for the intervention and control groups, respectively. Participants reported a decrease in fat bias for explicit/implicit wanting and explicit liking after 4 months and 1 year. For intuitive eating, the unconditional permission to eat decreased after 4 months, and the body-food choice congruence increased after 1 year. Changes in unconditional permission to eat and in body-food choice congruence were positively and negatively associated with both Δweight and with Δfat mass, respectively. Changes in explicit wanting for fat and taste bias were associated with Δweight. CONCLUSIONS: Food reward decreased after a moderate WL intervention. Participants successfully maintained their reduced weight, and most of the changes in eating behavior remained significant at the end of the follow-up period. Lifestyle interventions aiming at WL should also consider intuitive eating and food reward.

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.

Does adaptive thermogenesis occur after weight loss in adults? A systematic review.

Adaptive thermogenesis (AT) has been proposed to be a compensatory response that may resist weight loss (WL) and promote weight regain. This systematic review examined the existence of AT in adults after a period of negative energy balance (EB) with or without a weight stabilisation phase. Studies published until 15 May 2020 were identified from PubMed, Cochrane Library, EMBASE, MEDLINE, SCOPUS and Web of Science. Inclusion criteria included statistically significant WL, observational with follow-up or experimental studies, age > 18y, sample size ≥10 participants, intervention period ≥ 1week, published in English, objective measures of total daily energy expenditure (EE) (TDEE), resting EE (REE) and sleeping EE(SEE). The systematic review was registered at PROSPERO (2020 CRD42020165348). A total of thirty-three studies comprising 2528 participants were included. AT was observed in twenty-seven studies. Twenty-three studies showed significant values for AT for REE (82·8 %), four for TDEE (80·0 %) and two for SEE (100 %). A large heterogeneity in the methods used to quantify AT and between subjects and among studies regarding the magnitude of WL and/or of AT was reported. Well-designed studies reported lower or non-significant values for AT. These findings suggest that although WL may lead to AT in some of the EE components, these values may be small or non-statistically significant when higher-quality methodological designs are used. Furthermore, AT seems to be attenuated, or non-existent, after periods of weight stabilisation/neutral EB. More high-quality studies are warranted not only to disclose the existence of AT but also to understand its clinical implications on weight management outcomes.

Adaptive thermogenesis after moderate weight loss: magnitude and methodological issues.

PURPOSE: The aim of this study was (1) to assess AT through 13 different mathematical approaches and to compare their results; and (2) to understand if AT occurs after moderate WL. METHODS: Ninety-four participants [mean (SD); BMI, 31.1 (4.3) kg/m2; age, 43.0 (9.4) years; 34% females] underwent a 1-year lifestyle intervention (clinicaltrials.gov ID: NCT03031951) and were randomized to intervention (IG, n = 49) or control groups (CG, n = 45), and all measurements were made at baseline and after 4 months. Fat mass (FM) and fat-free mass (FFM) were measured by dual-energy X-ray absorptiometry and REE by indirect calorimetry. AT was assessed through 13 different approaches, varying in how REE was predicted and/or how AT was assessed. RESULTS: IG underwent a mean negative energy balance (EB) of 270 (289) kcal/day, p < 0.001), resulting in a WL of - 4.8 (4.9)% and an FM loss of - 11.3 (10.8)%. Regardless of approach, AT occurred in the IG, ranging from ~ - 65 to ~ - 230 kcal/day and three approaches showed significant AT in the CG. CONCLUSIONS: Regardless of approach, AT occurred after moderate WL in the IG. AT assessment should be standardized and comparisons among studies with different methodologies to assess AT must be avoided.

In-Season Body Composition Effects in Professional Women Soccer Players.

This study aimed to analyze anthropometric and body composition effects in professional soccer women players across the early and mid-competitive 2019/20 season. Seventeen players (age, height, body mass, and body mass index of 22.7 ± 6.3 years, 167.5 ± 5.6 cm, 60.7 ± 6.6 kg and 21.6 ± 0.2 kg/m2) from a Portuguese BPI League team participated in this study. The participants completed ≥80% of 57 training sessions and 13 matches. They were assessed at three points (before the start of the season (A1), after two months (A2), and after four months (A3)) using the following variables: body fat mass (BFM), soft lean mass (SLM), fat-free mass (FFM), intracellular water (ICW), extracellular water (ECW), total body water (TBW), and phase angle (PhA, 50 Khz), through InBody S10. Nutritional intake was determined through a questionnaire. Repeated measures ANCOVA and effect sizes (ES) were used with p < 0.05. The main results occurred between A1 and A2 for BFM (-21.7%, ES = 1.58), SLM (3.7%, ES = 1.24), FFM (4%, ES = 1.34), ICW (4.2%, ES = 1.41), TBW (3.7%, ES = 1.04). Furthermore, there were significant results between A1 and A3 for FFM (4.8%, ES = 1.51), ICW (5%, ES = 1.68), and PhA (10.4%, ES = 6.64). The results showed that the water parameters improved over time, which led to healthy hydration statuses. The training load structure provided sufficient stimulus for appropriate physical fitness development, without causing negative disturbances in the water compartments.

Glucosinolate Induction and Resistance to the Cabbage Moth, Mamestra brassicae, Differs among Kale Genotypes with High and Low Content of Sinigrin and Glucobrassicin.

The cabbage moth, Mamestra brassicae L. (Lepidoptera: Noctuidae), is a generalist insect pest of cruciferous crops. We tested glucosinolate induction by jasmonic acid (JA) and salicylic acid (SA), and by these phytohormones combined with feeding by M. brassicae larvae in four genotypes of kale, Brassica oleracea L. var. acephala (Brassicaceae). The genotypes tested had high glucobrassicin (genotype HGBS), low glucobrassicin (genotype LGBS), high sinigrin (genotype HSIN), and low sinigrin content (genotype LSIN). Application of JA increased indolic and total glucosinolate content in all kale genotypes 1, 3, and 9 days after treatment. For SA-treated plants, glucosinolate induction varied depending on the number of days after treatment and the genotype. Overall, herbivory by M. brassicae accentuated and attenuated the effects of JA and SA, respectively, on plant glucosinolate content. Larvae of M. brassicae gained less weight on leaves from plants treated with JA compared to leaves from control plants and plants treated with SA. In bioassays with leaf discs, a significant reduction of defoliation only occurred in JA-treated plants of the HSIN genotype. This research shows that previous herbivory alters the susceptibility of kale to M. brassicae and that induction of glucosinolates varies among kale genotypes differing in their glucosinolate content.

Specific Bioelectrical Impedance Vector Analysis Identifies Body Fat Reduction after a Lifestyle Intervention in Former Elite Athletes.

BACKGROUND: specific bioelectrical impedance vector analysis (BIVA) has been proposed as an alternative bioimpedance method for evaluating body composition. This investigation aimed to verify the ability of specific BIVA in identifying changes in fat mass after a 16-week lifestyle program in former athletes. METHODS: The 94 participants included in the Champ4life project (clinicaltrials.gov: NCT03031951) were randomized into intervention (n = 49) and control (n = 45) groups, from which 82 athletes completed the intervention (age 43.9 ± 9.2 y; body mass index 31.1 ± 4.6 kg/m2). Fat mass was estimated by dual-energy X-ray absorptiometry. Bioelectric resistance, reactance, phase angle, and vector length were assessed by bioelectric impedance spectroscopy, and the BIVA procedure was applied. RESULTS: A significant (p < 0.05) group x time interaction for fat mass, specific resistance, reactance, and vector length was found. Fat mass and vector length significantly (p < 0.05) decreased in the intervention group, while no change was measured in the control group. Considering the participants as a whole group, changes in vector length were associated with changes in fat mass percentage (r2 = 0.246; ß = 0.33; p < 0.001) even after adjusting for age, sex, and group (R2 = 0.373; ß = 0.23; p = 0.002). CONCLUSIONS: The specific BIVA approach is suitable to track fat mass changes during an intervention program aimed to reduce body fat in former athletes.

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 (ß = 2.158, p = 0.001), maximal isometric strength (upper-body: ß = 2.846, p = 0.012; low-er-body: ß = 24.209, p = 0.041) after adjusting for age, sex, and fat mass but not for VO2max (ß = -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.

Validity of water compartments estimated using bioimpedance spectroscopy in athletes differing in hydration status.

We aimed to validate bioelectrical impedance spectroscopy (BIS), compared with tracer dilution measurements, for assessing total body water (TBW), intracellular water (ICW), and extracellular water (ECW) in athletes differing in hydration status. A total of 201 athletes participated. Reference TBW and ECW were determined by deuterium and bromide dilution methods, respectively; ICW was calculated as TBW-ECW. Water compartments were estimated by BIS. Urine specific gravity (USG) classified athletes into well-hydrated (WH) (USG < 1.023), euhydrated (EH) (USG:1.024-1.026), and dehydrated (DH) (USG>1.027). No significant differences were found between BIS and the reference methods for WH, EH, and DH athletes for TBW, ICW nor ECW (p>0.05). Concordance of TBW and its compartments by method was significant (p < 0.001) with coefficients of determination ranging by hydration classification [EH:52-96%;DH:56-98%;WH:71-96%]. Bland-Altman analyses showed no trend for TBW and its compartments with the exception of ICW in the WH athletes. The 95% confidence BIS intervals for the WH group ranged from -3.08 to 2.68 kg for TBW, -4.28 to 4.14 kg for ICW, and -3.29 to 3.02 kg for ECW. For the EH athletes, the 95% confidence intervals ranged from -2.78 to 2.24 kg for TBW, -4.10 to 3.94 kg for ICW, and -3.44 to 3.06 kg for ECW. In DH group, TBW ranged between -1.99 and 2.01 kg, ICW between -3.78 and 6.34 kg, and ECW between -6.22 and 3.74 kg. These findings show that BIS is useful at a group level in assessing water compartments in athletes differing in hydration status. However, the usefulness of BIS is limited at an individual level, especially in dehydrated athletes.