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Purpose: To investigate differences in athletes’ knowledge, beliefs, and training practices during COVID-19 lockdowns with reference to sport classification and sex. This work extends an initial descriptive evaluation focusing on athlete classification. Methods: Athletes (12,526; 66% male; 142 countries) completed an online survey (May–July 2020) assessing knowledge, beliefs, and practices toward training. Sports were classified as team sports (45%), endurance (20%), power/technical (10%), combat (9%), aquatic (6%), recreational (4%), racquet (3%), precision (2%), parasports (1%), and others (1%). Further analysis by sex was performed. Results: During lockdown, athletes practiced body-weight-based exercises routinely (67% females and 64% males), ranging from 50% (precision) to 78% (parasports). More sport-specific technical skills were performed in combat, parasports, and precision (∼50%) than other sports (∼35%). Most athletes (range: 50% [parasports] to 75% [endurance]) performed cardiorespiratory training (trivial sex differences). Compared to prelockdown, perceived training intensity was reduced by 29% to 41%, depending on sport (largest decline: ∼38% in team sports, unaffected by sex). Some athletes (range: 7%–49%) maintained their training intensity for strength, endurance, speed, plyometric, change-of-direction, and technical training. Athletes who previously trained ≥5 sessions per week reduced their volume (range: 18%–28%) during lockdown. The proportion of athletes (81%) training ≥60 min/session reduced by 31% to 43% during lockdown. Males and females had comparable moderate levels of training knowledge (56% vs 58%) and beliefs/attitudes (54% vs 56%). Conclusions: Changes in athletes’ training practices were sport-specific, with few or no sex differences. Team-based sports were generally more susceptible to changes than individual sports. Policy makers should provide athletes with specific training arrangements and educational resources to facilitate remote and/or home-based training during lockdown-type events.

ContextIt remains uncertain whether aging before late adulthood and menopause are associated with fat-free mass and fat mass–adjusted resting energy expenditure (REEadj).ObjectivesWe investigated whether REEadjdiffers between middle-aged and younger women and between middle-aged women with different menopausal statuses. We repeated the age group comparison between middle-aged mothers and their daughters to partially control for genotype. We also explored whether serum estradiol and follicle-stimulating hormone concentrations explain REEadjin midlife.MethodsWe divided 120 women, including 16 mother–daughter pairs, into age groups; group I (n= 26) consisted of participants aged 17–21, group II (n= 35) of those aged 22–38 and group III (n= 59) of those aged 41–58 years. The women in group III were further categorized as pre- or perimenopausal (n= 19), postmenopausal (n= 30) or postmenopausal hormone therapy users (n= 10). REE was assessed using indirect calorimetry, body composition using dual-energy X-ray absorptiometry and hormones using immunoassays.ResultsThe REEadjof group I was 126 kcal/d (95% CI: 93–160) higher than that of group III, and the REEadjof group II was 88 kcal/d (95% CI: 49–127) higher. Furthermore, daughters had a 100 kcal/d (95% CI: 63–138 kcal/d) higher REEadjthan their middle-aged mothers (allP< 0.001). In group III, REEadjwas not lower in postmenopausal women and did not vary by sex hormone concentrations.ConclusionsWe demonstrated that REEadjdeclines with age in women before late adulthood, also when controlling partially for genetic background, and that menopause may not contribute to this decline.

We investigated the associations of physical activity (PA), sedentary time (ST), and diet quality with biomarkers of inflammation in 390 children (192 girls, 198 boys) aged 6–8 years. PA energy expenditure (PAEE), light PA, moderate PA (MPA), vigorous PA (VPA), moderate-to-vigorous PA (MVPA), and ST were assessed by combined movement and heart rate sensor. Finnish Children Healthy Eating Index was calculated using data from 4 d food records. Body fat percentage (BF%) was measured by dual-energy X-ray absorptiometry. High-sensitivity C-reactive protein (Hs-CRP), leptin, interleukin-6 (IL-6), adiponectin, tumour necrosis factor-α, and glycoprotein acetyls were measured from fasting blood samples. PAEE, MPA, VPA, and MVPA were inversely associated with hs-CRP (β=−191 to −139, 95% CI=−0.294 to −0.024), leptin (β=−0.409 to −0.301, 95% CI=−0.499 to −0.107), IL-6 (β=−0.136 to −0.104, 95% CI=−0.240 to −0.001) and PAEE, MPA, and MVPA were inversely associated with glycoprotein acetyls (β=−0.117 to −0.103, 95% CI=−0.213 to −0.001). ST was directly associated with hs-CRP (β=0.170, 95% CI=0.070–0.269), leptin (β=0.355, 95% CI=0.265–0.445), and IL-6 (β=0.105, 95% CI=0.005–0.205). VPA was inversely associated with hs-CRP, leptin, and IL-6 in children with higher BF% (β=−0.344 to −0.181, 95% CI=−0.477 to −0.033) but not among children with lower BF% (β=−0.007–0.033, 95% CI=−0.183–0.184). In conclusion, PA was inversely and ST directly associated with circulating levels of biomarkers of inflammation among children. Furthermore, we observed that PA was inversely associated with these biomarkers for inflammation in children with a higher BF%. Highlights Systemic inflammation, as indicated by increased circulating concentrations of biomarkers for inflammation, may be important in causal pathways leading to insulin resistance, sub-clinical atherosclerosis, and eventually clinical manifestations of cardiovascular diseases. Higher levels of physical activity and lower levels of sedentary time were associated with more favourable inflammatory profile. Body fat percentage modified these associations and especially vigorous intensity physical activity was inversely associated with biomarkers of inflammation on children with higher body fat percentage but not in children with lower body fat percentage.

AimTo evaluate differences in menstrual and pubertal history and trends in eating behaviours among women with and without a competitive sports background. Additionally, we investigated if menstrual history and eating behaviours are associated with sports career-related factors.MethodsThis retrospective study was conducted on 100 women with a competitive endurance sports background and their age-matched, gender-matched and municipality-matched controls (n=98). Data were collected using a questionnaire using previously validated instruments. Generalised estimating equations were used to calculate associations of menstrual history and eating behaviours with outcome variables (career length, participation level, injury-related harms and career termination due to injury).ResultsAthletes reported higher rates of delayed puberty and menstrual dysfunction than controls. No differences between the groups were observed in the Eating Disorder Examination Questionnaire short form (EDE-QS) scores at any age. Previous disordered eating (DE) was associated with current DE in both groups. Among athletes, higher EDE-QS scores during the sports career were associated with a shorter career (B=−0.15, 95% CI −0.26 to –0.05). Secondary amenorrhoea was associated with lower participation level (OR 0.51, 95% CI 0.27 to 0.95), injury-related harms during the career (OR 4.00, 95% CI 1.88 to 8.48) and career termination due to injury (OR 1.89, 95% CI 1.02 to 3.51).ConclusionThe findings indicate that DE behaviours and menstrual dysfunction, specifically secondary amenorrhoea, have a disadvantageous relationship with a sports career in women competing in endurance sports. DE during the sports career is associated with DE after the career.

Study aim: The aim of this study was to evaluate if young female skiers meet their energy and macronutrient requirements, and how energy availability (EA) and macronutrient intake affects their performance during an intensive training camp. Material and methods: 19 female cross-country skiers (age 16.7 ± 0.7) filled in 48-hour food and training logs during a 5-day training camp. Fasting concentrations of hemoglobin, leptin, triiodothyronine (T3), insulin, insulin-like growth factor 1 (IGF-1), and glucose were measured before (PRE) and after (POST) the camp. Blood lactate (LA), heart rate (HR) and rating of perceived exertion (RPE) from a submaximal treadmill running test, jump height from counter movement jump (CMJ), and power from a reactive jump test (RJ) were also measured PRE and POST. Results: Mean EA was 40.3 ± 17.3 kcal · kgFFM–1 · d–1. 58% of the participants had suboptimal EA, 37% had low EA, and 53% had suboptimal carbohydrate intake. HR, HR/RPE ratio, LA/RPE ratio, CMJ, hemoglobin, leptin, T3, and insulin decreased from PRE to POST. RPE and glucose increased from PRE to POST. EA during the camp correlated with changes in LA (r = 0.54, p = 0.018), LA/RPE (r = 0.65, p = 0.003), and RJ (r = 0.47, p = 0.043). Conclusions: Many athletes had difficulties in meeting their energy and carbohydrate requirements during a training camp. Furthermore, sufficient EA may help to avoid overreaching and to maintain performance during an intensive training period.

Exercise has been shown to affect gut the microbiome and metabolic health, with athletes typically displaying a higher microbial diversity. However, research on the gut microbiota and systemic metabolism in elite athletes remains scarce. In this study, we compared the gut microbiota profiles and serum metabolome of national team cross-country skiers at the end of an exhausting training and competitive season to those of normally physically-active controls. The gut microbiota were analyzed using 16S rRNA amplicon sequencing. Serum metabolites were analyzed using nuclear magnetic resonance. Phylogenetic diversity and the abundance of several mucin-degrading gut microbial taxa, including Akkermansia, were lower in the athletes. The athletes had a healthier serum lipid profile than the controls, which was only partly explained by body mass index. Butyricicoccus associated positively with HDL cholesterol, HDL2 cholesterol and HDL particle size. The Ruminococcustorques group was less abundant in the athlete group and positively associated with total cholesterol and VLDL and LDL particles. We found the healthier lipid profile of elite athletes to co-occur with known health-beneficial gut microbes. Further studies should elucidate these links and whether athletes are prone to mucin depletion related microbial changes during the competitive season.

This study aimed to examine the effects of fatiguing power loading on neuromuscular properties, force production, and metabolic capacities during four phases of the menstrual cycle (MC): menstruation (M), midfollicular (mid FOL), ovulation (OV), and midluteal (mid LUT).Sixteen eumenorrheic women performed sessions of maximal explosive leg press (2 × 10 at 60% one-repetition maximum load with 2-min recovery between sets). Serum hormones and neuromuscular responses were measured.The loading protocol significantly decreased power (between -14.2% and -12.5%; P0.001) and maximal force production (between maximum voluntary force (MVC); -15.0% and -7.8%; P0.001-0.05), while decreasing activation level (between AL; -6.9% and -2.2%; P0.001-0.05) in all MC phases. The decreases in AL were greater during mid LUT (P0.01) compared with OV. Changes in MVC and AL were associated (r2 = 0.53; P0.01) at all MC phases. The decrease in EMG during MVC did not differ between the MC phases; however, mean power frequency was higher during M (+7.7%; P0.05) and mid LUT (+3.1%; P0.05) compared with OV (-7.5%). Resting twitch force decreased during mid FOL (-6.9%; P0.05) and mid LUT (-16.2%; P0.001), and these values were significantly decreased (P0.05) compared with OV. In addition, resting twitch force at mid LUT was lower (P0.01) compared with M. Blood lactate levels increased more (P0.05) during M compared with mid LUT. Some serum hormone concentrations were associated with fatigue-induced changes in neuromuscular properties and force production, but these correlations behaved differently between the MC phases.OV may offer a more favorable hormonal milieu for acute neural responses, whereas mid FOL and mid LUT seem to be superior for acute muscular responses.

Purpose Whether elite athletes, who have been exposed to vigorous-intensity exercise combined with other stressors, have elevated systemic low-grade inflammation, remains largely unclear. To address this question, we studied the levels of six inflammatory cytokines as potential biomarkers of a low-grade inflammatory state in elite athletes after an 11-month training and competition season. Methods We collected sera from 27 Finnish elite cross-country skiers and 27 gender- and age-matched, moderately-exercising controls. The serum concentrations of C-reactive protein (CRP), interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α), glycoprotein acetyls (GlycA), interleukin 10 (IL-10), and interferon gamma (IFN-γ) cytokines were quantified as surrogate markers of low-grade inflammation. Results The athletes were found to have significantly lower concentrations of CRP (P = 0.0232) and higher concentrations of IL-10, TNF-α, and IFN-γ (P = 0.0097, P = 0.0256, and P = 0.0185, respectively) than the controls. No significant differences between athletes and controls were detected in the concentrations of IL-6 and GlycA. The inflammatory score (IS) did not differ significantly between athletes and controls. Conclusion The results of this study argued against the hypothesis of a significant chronic low-grade inflammation in response to prolonged high-performance exercise among elite endurance athletes.

Objectives The influence of hormonal contraceptives (HC) on inflammation and body composition after high-intensity combined strength and endurance training was investigated. Design Active healthy women formed two training groups: HC users (HCU, n = 9) and those who had never used HC (NHC, n = 9). Training included two strength training sessions and two high-intensity interval training sessions per week for 10 weeks. Methods Before (PRE) and after (POST) the training intervention, high-sensitivity C-reactive protein (hs-CRP), tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), and interleukin-1beta (IL-1β) concentrations were measured. Dual-energy X-ray absorptiometry was used to estimate fat mass (FM), abdominal fat mass (aFM), and lean mass (LM). Results Circulating concentrations of hs-CRP decreased significantly in the NHC from pre to post with −0.46 mg l−1 (95% CI: −0.78, −0.14, p = 0.009, ES = 0.434), whereas a significant increase was observed in HCU from pre to post with 0.89 mg l−1 (95% CI: 1.66, 0.12, p = 0.048, ES = 1.988) with a significant between-group difference (p = 0.015). In addition, hs-CRP concentration was significantly higher in HCU than in NHC after training (p = 0.036) at post. Lean mass increased significantly more in NHC than in HCU (p = 0.049). Conclusions High-intensity combined strength and endurance training can modify inflammation and body composition of women. The present study showed that inflammation, in terms of hs-CRP was higher post training in HCU than NHC, which may be associated with smaller gains in lean mass in response to training.

Myllyaho, MM, Ihalainen, JK, Hackney, AC, Valtonen, M, Nummela, A, Vaara, E, Häkkinen, K, Kyröläinen, H, and Taipale, RS. Hormonal contraceptive use does not affect strength, endurance, or body composition adaptations to combined strength and endurance training in women. J Strength Cond Res 35(2): 449-457, 2021-This study examined the effects of a 10-week period of high-intensity combined strength and endurance training on strength, endurance, body composition, and serum hormone concentrations in physically active women using hormonal contraceptives (HCs, n = 9) compared with those who had never used hormonal contraceptives (NHCs, n = 9). Training consisted of 2 strength training sessions and 2 high-intensity running interval sessions per week. Maximal bilateral isometric leg press (Isom), maximal bilateral dynamic leg press (one repetition maximum [1RM]), countermovement jump (CMJ), a 3,000-m running test (3,000 m), body composition, and serum hormone levels were measured before and after training between days 1-5 of each subject's menstrual cycle. Both groups increased 1RM and CMJ: HC = 13.2% (p0.001) and 9.6% (p0.05), and NHC = 8.3% (p0.01) and 8.5% (p0.001). Hormonal contraceptive improved 3,000 m by 3.5% (p0.05) and NHC by 1% (n.s.). Never used hormonal contraceptive increased lean mass by 2.1% (p0.001), whereas body fat percentage decreased from 23.9 ± 6.7 to 22.4 ± 6.0 (-6.0%, p0.05). No significant changes were observed in body composition in HC. No significant between-group differences were observed in any of the performance variables. Luteinizing hormone concentrations decreased significantly (p0.05) over 10 weeks in NHC, whereas other hormone levels remained statistically unaltered in both groups. It seems that the present training is equally appropriate for improving strength, endurance, and body composition in women using HC as those not using HC without disrupting hypothalamic-pituitary-gonadal axis function.

The Tour de Ski (TDS: 6–9 sprint and distance races across 9–11 days) represents the most intense competition series of the cross-country (XC) ski season and is characterized by accumulated stress from consecutive days of high-intensity (~ 85%–160% VO2max) racing, travel, cold temperatures and low to moderate altitude (500–1500 m above sea level). Here, nutritional strategies play a key supportive role for optimized health, recovery and performance. This narrative review aims to provide an evidence-based discussion on the energetic demands of the TDS and recommendations for nutritional strategies to optimize health and performance of XC skiers during and following the TDS. We highlight several challenges that may arise during the TDS, including the following: poor energy availability (EA) due to decreased appetite or a pressure to maintain a low body weight, suboptimal carbohydrate availability due to a failure to replenish muscle glycogen stores across consecutive-day racing and increased risk of illness due to a combination of factors, including high-intensity racing, poor nutrition, sleep, travel and hygiene. We encourage XC skiers to maintain optimal overall EA across the ~ 1.5-week period, ensure high daily carbohydrate availability, as well as the use of strategies to maintain a healthy immune system. In addition, we include practical guidelines on the management of nutrition support prior to and during the TDS. We recognize that many nutritional questions remain unanswered both in the context of elite XC ski racing and specifically for extreme demands like the TDS that should be addressed in future investigations. peerReviewed

Purpose The aim of this study was to compare the efficacy of three water immersion interventions performed after active recovery compared to active recovery only on the resolution of inflammation and markers of muscle damage post-exercise. Methods Nine physically active men (n = 9; age 20‒35 years) performed an intensive loading protocol, including maximal jumps and sprinting on four occasions. After each trial, one of three recovery interventions (10 min duration) was used in a random order: cold-water immersion (CWI, 10 °C), thermoneutral water immersion (TWI, 24 °C), contrast water therapy (CWT, alternately 10 °C and 38 °C). All of these methods were performed after an active recovery (10 min bicycle ergometer), and were compared to active recovery only (ACT). 5 min, 1, 24, 48, and 96 h after exercise bouts, immune response and recovery were assessed through leukocyte subsets, monocyte chemoattractant protein-1, myoglobin and high-sensitivity C-reactive protein concentrations. Results Significant changes in all blood markers occurred at post-loading (p p < 0.01). Only lymphocytes displayed satisfactory reliability in the exercise response, with intraclass correlation coefficient > 0.5. Conclusions The recovery methods did not affect the resolution of inflammatory and immune responses after high-intensity sprinting and jumping exercise. It is notable that the biomarker responses were variable within individuals. Thus, the lack of differences between recovery methods may have been influenced by the reliability of exercise-induced biomarker responses.

Purpose: To determine body composition, energy availability, training load, and menstrual status in young elite endurance running athletes (ATH) over 1 year, and in a secondary analysis, to investigate how these factors differ between nonrunning controls (CON), and amenorrheic (AME) and eumenorrheic (EUM) ATH. Correlations to injury, illness, and performance were also examined. Methods: Altogether 13 ATH and 8 CON completed the Low Energy Availability in Females Questionnaire. Anthropometric, energy intake, and peak oxygen uptake assessments were made at 4 time points throughout the year: at baseline post competition season, post general preparation, post specific preparation, and post competition season the following year. Logs of physical activity, menstrual cycle, illness, and injury were kept by all participants. Performance was defined using the highest International Association of Athletics Federations points prior to and after the study. Results: ATH had significantly lower body mass (P P P P P P r P Conclusions: More than half of this group of runners was AME, and they were injured more and ran less than their EUM counterparts. Furthermore, only the EUM runners increased their performance over the course of the year.

Purpose: To examine the potential impact of fluctuations in sex steroid hormones across the menstrual cycle (MC) on marathon running performance of recreational female athletes. Methods: A survey questionnaire was administered to recreational, nonelite runners who had completed multiple marathons within the last 18 months. Results: A total of 599 questionnaires were returned and deemed viable for review. From these, 185 survey participants were found to have complete information and eligibility to have their surveys used in the statistical analysis. A total of 106 women had their best marathon performance in the luteal phase (high sex steroid hormones) of the MC, and 79 had their best performance in the follicular phase (low sex steroid hormones) of the MC (responses were significantly different; z-score value = 1.11; P Conclusion: Recreational female runners have varying performances in the marathon across their MC phases, specifically performing better in the luteal phase of the cycle.

Our primary aim was to study the effects of a 4-week preparatory resistance-training (RT) period followed by 12 weeks of 2 specific RT protocols (either hypertrophic-strength (HS) or strength-hypertrophy-power training) on inflammation markers and the possible relationship of the changes in abdominal fat and lean mass to the changes in inflammation status. A total of 82 healthy men were included in the study. Maximal concentric leg press strength (1-repetition maximum), total body lean mass, total body and abdominal fat mass, circulating high-sensitivity C-reactive protein, interleukin-6, interleukin-1 receptor antagonist (IL-1ra), monocyte chemoattractant protein 1 (MCP-1), and selected adipocytokines (resistin, adiponectin, and leptin) concentrations were measured before and after 4 (wk4) and 16 weeks (wk16) of RT. After the initial phase of RT, on wk4, abdominal and total fat mass as well as plasma leptin concentrations were significantly reduced (p < 0.05), whereas muscle mass, IL-1ra, resistin, and MCP-1 concentrations were significantly increased (p < 0.05). During specialized training phase, at wk16, only HS led to further reduction in abdominal and total fat mass, resistin, and leptin (p < 0.05), whereas both training modes led to lower MCP-1 concentrations (p < 0.05). Abdominal fat mass and circulating leptin were reduced already after 4 weeks of RT. Simultaneously, circulating MCP-1 and resistin concentrations increased, possibly as markers of muscle adaptation and regeneration. The present findings also suggest that RT with hypertrophic focus is beneficial for further reductions in abdominal fat mass and to decrease circulating inflammatory markers.

Our primary aim was to study the effects of 24 weeks of combined aerobic and resistance training performed on the same day or on different days on inflammation markers. Physically active, healthy young men were randomly divided into three groups that performed: aerobic and resistance training consecutively in the same training session (SS) 2-3 days wk-1 or on alternating days (AD) 4-6 days wk-1 as well as control (C). The total training volume was matched in the training groups. The control group was asked to maintain their habitual physical activity and exercise level. Maximal leg press strength (1RM) and peak oxygen uptake (VO2peak ) were measured. Abdominal fat mass was estimated with dual-energy absorptiometry (DXA). High-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), monocyte chemoattractant protein 1 (MCP-1), tumor necrosis factor alpha (TNF-α), and adipocytokines resistin, adiponectin, and leptin were analyzed from plasma samples. Training significantly reduced circulating hs-CRP, leptin, and resistin in both training groups (P

Ahokas, EK, Ihalainen, JK, Kyrolainen, H, and Mero, AA. Effects of water immersion methods on postexercise recovery of physical and mental performance. J Strength Cond Res 33(6): 1488-1495, 2019-The aim of this study was to compare the effectiveness of 3 water immersion interventions performed after active recovery compared with active recovery only on physical and mental performance measures and physiological responses. The subjects were physically active men (age 20-35 years, mean ± SD 26 ± 3.7 years). All subjects performed a short-term exercise protocol, including maximal jumps and sprinting. Four different recovery methods (10 minutes) were used in random order: cold water immersion (CWI, 10° C), thermoneutral water immersion (TWI, 24° C), and contrast water therapy (CWT, alternately 10° C and 38° C). All these methods were performed after an active recovery (10-minute bicycle ergometer; heart rate [HR] 120-140 b·min, 60-73% from age-calculated maximum HR), and the fourth method was active recovery (ACT) only. Within 96 hours after exercise bouts, recovery was assessed through a 30-m maximal sprint test, maximal countermovement jump (CMJ), self-perceived muscle soreness and relaxation questionnaires, and blood lactate, creatine kinase, testosterone, cortisol, and catecholamine levels. The self-perceived feeling of relaxation after 60-minute recovery was better (p < 0.05) after CWI and CWT than ACT and TWI. Statistically significant differences were not observed between the recovery methods in any other marker. In the 30-m sprint test, however, slower running time was found in ACT (p < 0.001) and CWT (p = 0.005), and reduced CMJ results (p < 0.05) were found in ACT when the results were compared with baseline values. Based on these findings, it can be concluded that CWI and CWT improve the acute feeling of relaxation that can play a positive role in athletes' performance and well-being.

Summary Study aim: The purpose of this study was to compare the effects of cold-water immersion (CWI) vs. active recovery performed after each individual strength and endurance training session over a 10-week period of high-intensity combined strength and endurance training. Materials and methods: Seventeen healthy men completed 10 weeks of high-intensity combined strength and endurance training. One group (AR, n = 10) completed active recovery that included 15 minutes of running at 30–40% VO2max after every strength training session while the other group (CWI, n = 7) completed 5 minutes of active recovery (at the same intensity as the AR group) followed by 10 minutes of cold-water (12 ± 1°C) immersion. During CWI, the subjects were seated passively during the 10 minutes of cold-water immersion and the water level remained just below the pectoral muscles. Muscle strength and power were measured by isometric bilateral, 1 repetition maximum, leg press (ISOM LP) and countermovement jump (CMJ) height. Endurance performance was measured by a 3000 m running time trial. Serum testosterone, cortisol, and IGF-1 were assessed from venous blood samples. Results: ISOM LP and CMJ increased significantly over the training period, but 3000 m running time increased only marginally. Serum testosterone, cortisol, and IGF-1 remained unchanged over the intervention period. No differences between the groups were observed. Conclusions: AR and CWI were equally effective during 10 weeks of high-intensity combined strength and endurance training. Thus, physically active individuals participating in high-intensity combined strength and endurance training should use the recovery method they prefer.

The main purpose of the present study was to investigate the effect of frequency, thereby increasing training volume, of resistance training on body composition, inflammation markers, lipid and glycemic profile in healthy older individuals (age range 65-75 year). Ninety-two healthy participants were randomly assigned to one of four groups; performing strength training one- (EX1), two- (EX2), or three- (EX3) times-per-week and a non-training control (CON) group. Whole-body strength training was performed using 2-5 sets and 4-12 repetitions per exercise and 7-9 exercises per session. All training groups attended supervised resistance training for 6 months. Body composition was measured by dual X-ray absorptiometry and fasting blood samples were taken pre- and post-training. There were significant main effects of time for total fat mass (F = 28.12, P < 0.001) and abdominal fat mass (F = 20.72, P < 0.001). Pre- to post-study, statistically significant reductions in fat mass (Delta = -1.3 +/- 1.4 kg, P < 0.001, n = 26) were observed in EX3. Pre- to post-study reductions in low density lipoprotein (LDL) concentration (Delta = -0.38 +/- 0.44 mmol.L-1 , P = 0.003, n = 19) were observed only in EX3, whereas a significant pre- to post-study increases in high density lipoprotein (HDL) concentration (0.14-0.19 mmol.L-1) were observed in all training groups. Most variables at baseline demonstrated a significant (negative) relationship when correlating baseline values with their change during the study including: Interleukin-6 (IL-6) (r = -0.583, P < 0.001), high-sensitivity c-reactive protein (hs-CRP) (r = -0.471, P < 0.001, and systolic blood pressure (r = -0.402, P = 0.003). The present study suggests that having more than two resistance training sessions in a week could be of benefit in the management of body composition and lipid profile. Nevertheless, interestingly, and importantly, those individuals with a higher baseline in systolic blood pressure, IL-6 and hs-CRP derived greatest benefit from the resistance training intervention, regardless of how many times-a-week they trained. Finally, the present study found no evidence that higher training frequency would induce greater benefit regarding inflammation markers or glycemic profile in healthy older adults.

Prolonged effects of dietary acid intake on acid–base status and kidney function have not yet been studied in an intervention study in healthy subjects. Dietary acid load can be estimated by calculating the potential renal acid load (PRAL) of foods. Effects of low-PRAL and moderate-PRAL diets on acid–base status and kidney function were investigated during a 12-week exercise training period. Healthy, 20–50-year-old men (n = 21) and women (n = 25) participated in the study and were randomly divided into low-PRAL and moderate-PRAL groups. Before (PRE), mid-phase (MID) and after the intervention (POST), the subjects participated in measurement sessions, where a 12-h urine sample and fasting blood samples were collected, and a submaximal cycle ergometer test was performed. Net acid excretion was significantly lower after 12 weeks of the low-PRAL diet as compared to the moderate-PRAL diet, both in men and women. In low-PRAL females, capillary pH and bicarbonate were significantly higher at 75% of VO2max at POST as compared to PRE. Glomerular filtration rate decreased over the study period in moderate-PRAL men and women. The results of the present study suggest that an acidogenic diet and regularly training together may increase the acidic load of the body and start to impair the kidney function in recreationally active subjects. peerReviewed

New Findings: What is the central question of this study? Can phenotypic traits associated with low response to one mode of training be extrapolated to other exercise-inducible phenotypes? The present study investigated whether rats that are low responders to endurance training are also low responders to resistance training. What is the main finding and its importance? After resistance training, rats that are high responders to aerobic exercise training improved more in maximal strength compared with low-responder rats. However, the greater gain in strength in high-responder rats was not accompanied by muscle hypertrophy, suggesting that the responses observed could be mainly neural in origin. Abstract: The purpose of this study was to determine whether rats selectively bred for low and high response to aerobic exercise training co-segregate for differences in muscle adaptations to ladder-climbing resistance training. Five high-responder (HRT) and five low-responder (LRT) rats completed the resistance training, while six HRT and six LRT rats served as sedentary control animals. Before and after the 6 week intervention, body composition was determined by dual energy X-ray absorptiometry. Before tissue harvesting, the right triceps surae muscles were loaded by electrical stimulation. Muscle fibre cross-sectional areas, nuclei per cell, phosphorylation status of selected signalling proteins of mTOR and Smad pathways, and muscle protein, DNA and RNA concentrations were determined for the right gastrocnemius muscle. The daily protein synthesis rate was determined by the deuterium oxide method from the left quadriceps femoris muscle. Tissue weights of fore- and hindlimb muscles were measured. In response to resistance training, maximal carrying capacity was greater in HRT (∼3.3 times body mass) than LRT (∼2.5 times body mass), indicating greater improvements of strength in HRT. However, muscle hypertrophy that could be related to greater strength gains in HRT was not observed. Furthermore, noteworthy changes within the experimental groups or differences between groups were not observed in the present measures. The lack of hypertrophic muscular adaptations despite considerable increases in muscular strength suggest that adaptations to the present ladder-climbing training in HRT and LRT rats were largely induced by neural adaptations.

The purpose of the present study was to examine the immediate and prolonged immune response in circulating cytokine and adipocytokine concentrations after two different resistance exercise bouts: hypertrophic (HYP1, 5 × 10, 80% of 1RM) and maximal explosive (POW1, 10 × 5, 60% of 1RM) resistance exercise bouts and how 12 weeks of resistance training (RT) modifies these responses (HYP2, POW2). Eight men completed the study. RE-induced interleukin-6 (IL-6), interleukin-1β (IL-1β), interleukin-1 receptor antagonist (IL-1ra), monocyte-chemoattractant protein-1 (MCP-1), leptin, resistin, and adiponectin were measured before (PRE) and immediately (POST0), 24 (POST24) and 48 (POST48) hours after RE bouts before and after RT. In the untrained state, IL-6 increased immediately after RE in HYP1 (p = 0.002) and in POW1 (p = 0.003) whereas no changes were observed after RT. Similar results were observed in IL-1β, whereas conversely, IL-1ra increased only after RT in HYP2 and POW2 (p < 0.05). Resistin increased before RT in HYP1 and in POW1 (p = 0.011 and p = 0.003, respectively), but after RT, significant responses were not observed. Interestingly, in HYP2, MCP-1 increased significantly at POST24 (p = 0.009) and at POST48 (p = 0.032) only following RT. The present study shows that RT modifies RE-induced cytokine responses towards an anti-inflammatory direction. peerReviewed

The present study investigated the effects of a 12-week endurance-training intervention on salivary proteins and upper respiratory tract symptoms (URS) in 25 young men. Saliva samples of 25 recreational male endurance runners (age 34.6 years, body mass index = 23.8 kg·m−2, peak aerobic capacity = 47.2 mL·kg−1·min−1) were collected before (PRE) and after (POST) the training intervention, in a fasting state, as well as both before and after a maximal incremental treadmill run. The training consisted of both continuous and interval training sessions, 4–6 times per week based on the polarized training approach. Participants filled in Wisconsin Upper Respiratory Symptom Survey-21 and were retrospectively divided into 2 groups according to whether they reported URS (URS group, n = 13) or not (HEALTHY group, n = 12). Basal salivary immunoglobulin A (sa-sIgA) levels were significantly higher (+70%, p < 0.05) in the HEALTHY group both at PRE and POST whereas no significant differences were observed in salivary immunoglobulin M, salivary immunoglobulin G, lysozyme, or salivary α-amylase activity (sAA). Sa-sIgA concentration at PRE significantly correlated with the number of sick-days (R = –0.755, p < 0.001) in all subjects. The incremental treadmill run acutely increased sAA significantly (p < 0.05) at PRE (200%) and POST (166%) in the HEALTHY group but not in the URS group. This study demonstrated that subjects, who experienced URS during the 12 weeks of progressive endurance training intervention, had significantly lower basal sa-sIgA levels both before and after the experimental endurance training period. In addition to sa-sIgA, acute sAA response to exercise might be a possible determinant of susceptibility to URS in endurance runners.

The purpose of this study was to examine the acute immune response (circulating levels of leukocytes, cytokines and adipocytokines) to maximal resistance (MAX, 15 × 1RM) and hypertrophic resistance (HYP, 5 × 10RM) exercise bouts. Twelve healthy men (age = 28.2 ± 3.5 years, weight = 78.6 ± 10.4 kg, height 178.8 ± 5.0 cm, fat percentage = 16.5 ± 3.5 %) participated in the study. Blood was sampled before, immediately after and 15 and 30 min after exercise. Leukocytes (WBC) significantly increased immediately after HYP (p

The purpose of this study was to investigate the effect of ingestion of fluids with different carbohydrate concentrations (0, 1.5, and 7%) on the acute immune stress responses after high-intensity long-distance running. Continuous 18- to 20-km run was performed at 75% of maximal oxygen uptake with carbohydrate supplementation (CHO7%, 7% carbohydrate solution) and low-carbohydrate supplementation (lowCHO1.5%, 1.5% carbohydrate solution) in a randomized, double-blind, placebo (PLA) controlled design. Seven recreational runners (4 men and 3 women) completed all 3 trials. Blood was collected at baseline (PRE) and immediately after the run (POST). The running task induced significant (p ≤ 0.05) increases in leukocyte (white blood cells), neutrophil, and interleukin-6 (IL-6) counts in every trial. There was a significant (p ≤ 0.05) increase in cortisol with PLA and lowCHO1.5% but not with CHO7%. Increase in total leukocyte and neutrophil concentration was significantly lower with CHO7% compared with PLA (p ≤ 0.05). Postexercise IL-6 levels were significantly elevated when compared with baseline in all conditions (p ≤ 0.05). Interleukin-6 (IL-6) concentrations did not differ significantly between trials. LowCHO1.5% sport drink did not significantly differ from PLA in measured variables, which indicated that the amount and rate of carbohydrate ingestion (15 g, 10 g·h) in low-carbohydrate sport drink was not enough to significantly protect from the stress induced by high-intensity long-distance running, whereas the ingestion of CHO7% (45 g·h) blunted the significant cortisol response and significantly decreased the leukocyte response.