The Effect of Whole-Body Electromyostimulation Program on Physical Performance and Selected Cardiometabolic Markers in Obese Young Females.

Background and Objectives: Whole-body electromyostimulation is under investigation as a potential aid for obesity-related health problems, supplementing a comprehensive, evidence-based obesity management strategy that includes lifestyle, diet, and exercise. The study investigated the impact of a whole-body electromyostimulation training program on physical performance and cardiometabolic markers in young obese females. Materials and Methods: Twenty-eight obese females, aged over 18 years with BMI over 30 and body fat over 28% and no underlying health conditions or medication, were divided into a whole-body electromyostimulation group (15 participants) and a control group (13 participants). The whole-body electromyostimulation program lasted 12 weeks, with two 20 min sessions weekly, using bipolar, rectangular current. Assessments pre and post intervention included body composition, blood pressure, lipid profile, C-reactive protein levels, maximal oxygen consumption, and jumping and sprint performance. Two-way ANOVA and t-tests were used for analysis. Results: Statistical analysis revealed significant (group × time) interactions for body composition, systolic blood pressure, maximal oxygen consumption, jumping and sprint performance, and plasma levels of lipids and C-reactive protein. Post hoc analyses for the whole-body electromyostimulation group indicated improvements in body composition indices (p < 0.01), systolic blood pressure (p = 0.003), maximal oxygen consumption (p = 0.010), and both jumping and 30 m sprint performance (p < 0.001 and p = 0.001, respectively) after the intervention. Furthermore, plasma levels of lipids (p < 0.01) and C-reactive protein (p = 0.002) showed significant improvements following the training program. In contrast, no significant changes were observed for these variables in the control group. Conclusions: A 12-week whole-body electromyostimulation program significantly improved body composition (skeletal muscle mass, body mass index, body fat, and waist circumference), physical performance (maximal oxygen consumption, jumping and sprint performance), and certain cardiometabolic (plasma level of lipids) and inflammatory markers (C-reactive protein) in obese young women. Further research is needed to explore the broader effects of whole-body electromyostimulation on physical and cardiometabolic health.

Interval Training with Different Intensities in Overweight/Obese Adolescent Females.

To compare the effects of 12 weeks of high-intensity interval training (HIIT) versus moderate-intensity interval training (MIIT) on hematological and inflammatory markers in youth females, 38 overweight/obese females (16.4±1.0 yrs.) were randomly assigned to HIIT (2×6-8 repetitions of 30 s at 100-110% maximal aerobic speed (MAS), with 30 s active recovery between repetitions at 50% MAS; n=13), MIIT (2×6-8 repetitions of 30 s at 70-80% MAS, with 30 s active recovery between repetitions at 50% MAS; n=13), and a control group (CG, no intervention; n=12). Body composition, blood pressure, maximal heart rate, hematological and inflammatory markers (C-reactive protein [CRP], and erythrocyte sedimentation rate [ESR]) markers were assessed in all groups before and following the training program. Results revealed a significant (P<0.05) interaction effect for body composition, systolic blood pressure (SBP), MAS, maximal heart rate, and CRP. Within-group analyses for the HIIT and MIIT groups showed significant improvements in body mass (P=0.009 and P=0.025, respectively), BMI Z-score (P=0.011 and P=0.028, respectively), and MAS (P<0.001 and P=0.011, respectively). The HIIT program showed a significant decrease in body fat (P=0.002), waist circumference (P=0.002), maximal heart rate (P=0.003), SBP (P=0.001), and plasma CRP (P=0.004). In both groups, no significant changes were observed in ESR and hematological markers after intervention. No variable changed in CG. HIIT was the effective method to manage cardiometabolic health and inflammatory disorders in obese youth.

The Sex Difference in 6-h Ultra-Marathon Running-The Worldwide Trends from 1982 to 2020.

Background and Objectives: The 6-h ultra-marathon is the shortest time-limited ultra-marathon race, but little has been investigated regarding this race format. Previously, only the age of peak performance in the context of longer time-limited ultra-marathons was determined. The purpose of this study was to investigate the trends in 6-h ultra-marathon races from 1982 to 2020 for female and male ultra-runners, the participation and performance by countries, the age of peak performance, and the differences in performance regarding countries. Materials and Methods: The sample included 23,203 female ultra-runners, aged 18-83 years, and 87,264 male ultra-runners, aged 18-85 years, who were finishers in a 6-h ultra-marathon held between 1982 and 2020. The age of peak performance was tested using the Kruskal-Wallis test, followed by the Bonferroni Correction. The difference in performance by countries was verified using a linear regression model with the fastest runners from Russia in women, and Tunisia in men, used as reference. Results: Over the years, the men-to-women ratio decreased. The mean age was 43.20 ± 9.30 years for female and 46.09 ± 10.17 years for male runners. Athletes in younger age groups were faster than athletes in older age groups. Most female and male participants originated from Germany. Women from Russia (10.01 ± 1.28 km/h) and men from Tunisia (12.16 ± 1.46 km/h) were the fastest. Conclusions: In summary, in 6-h ultra-marathons held between 1982 and 2020, the participation for both women and men increased, while the men-to-women ratio decreased. The mean age was higher in men compared to women. Most female and male runners originated from Germany, but the fastest women were from Russia, and the fastest men from Tunisia. Future studies need to investigate whether Russian women and Tunisian men are also the best in other distance-limited ultra-marathon races, such as 12-h and 24-h.

Inflammatory cytokines and metabolic responses to high-intensity intermittent training: effect of the exercise intensity.

To examine the effects of two high-intensity intermittent training (HIIT) programs of varying intensities (100% vs. 110% of maximal aerobic velocity [MAV]) on metabolic, hormonal and inflammatory markers in young men. Thirty-seven active male volunteers were randomly assigned into: HIIT experimental groups (100% MAV [EG100, n = 9] and 110% MAV [EG110, n = 9]) and a control groups (CG100, n = 9 and CG110, n = 9). Particpants performed high intesity intermittent exercise test (HIIE) at 100% or 110% MAV. Venous blood samples were obtained before, at the end of HIIE and at 15 min of recovery, and before and after 8 weeks of HIIT programs. After training, Glucose was lower (p < 0.01) in EG100 (d = 0.72) and EG110 (d = 1.20) at the end of HIIE, and at 15 min recovery only in EG110 (d = 0.95). After training, Insulin and Cortisol were lower than before training in EG100 and EG110 at the end of HIIE (p < 0.001). After HIIT, IL-6 deceased (p < 0.001) in EG100 (d = 1.43) and EG110 (d = 1.56) at rest, at the end of HIIE (d = 1.03; d = 1.75, respectively) and at 15 min of recovery (d = 0.88;d = 1.7, respectively). This decrease was more robust (p < 0.05) in EG110 compared to EG100. After HIIT, TNF-α deceased (p < 0.001) in EG100 (d = 1.43) and EG110 (d = 0.60) at rest, at the end of HIIE (0.71 < d < 0.98) and at 15 min of recovery (0.70 < d < 2.78). HIIT with 110% MAV is more effective in young males on the improvements of some metabolic (Glucose), hormonal (Cortisol) and inflammatory (IL-6) markers at rest, at the end of HIIE and 15 min of recovery than training at 100 % MAV.

Fear of failure in Brazilian runners.

This study aims to investigate the fear or failure (FoF) in Brazilian runners of both sex, performance levels and age categories, as well as to verify the relationship between FoF and socioeconomic status (SES). Sample size as composed by 916. Age, sex, body height, body weight, SES, and running pace were self-reported. The Multidimensional Questionnaire of FoF was applied in an online platform. Running pace, and SES were categorized and processed through multivariate analysis and Spearman correlations, with the p-value set at 0.05. Female runners with better performance (2.13 ± 0.74) and younger (2.16 ± 0.80), as a well as male runners with worse performance (2.04 ± 0.69) and older (2.04 ± 0.89) presented the highest values of FoF. Among women, SES was negatively associated with FoF (r = -0.144; p = 0.006), while a positive association between running pace and SES was observed among men (r = 0.290; p < 0.001). Non-professional Brazilian runners presented low values of FoF.

Association of selected adipokines with metabolic syndrome and cardio-metabolic risk factors in young males.

The study aimed to investigate association of circulating leptin, adiponectin, chemerin, and omentin-1 with metabolic syndrome (MetS) and cardio-metabolic risk factors in youths. Thirty eight young males were enrolled. Participants underwent anthropometric and blood pressure measures, and fasting blood sampling. Plasma leptin, adiponectin, chemerin, omentin-1 and insulin were measured by ELISA methods. Multiple linear regression models, adjusting for age, MetS traits, C-reactive protein (CRP) and homeostasis model assessment of insulin resistance (HOMA-IR), were applied to determine correlates for each adipokine. Eleven participants meet criteria of MetS. These individuals had higher leptin and chemerin and lower adiponectin plasma concentrations than those without MetS. Plasma leptin and chemerin were positively related, and adiponectin and omentin-1 were inversely related to cardio-metabolic traits. In multivariate models, predictors of leptin were age (ß, 0.20, P = 0.01), abdominal obesity (ß, 0.24, P = 0.06), raised blood pressure (ß, 0.40, P = 0.01), raised triglycerides (ß, 0.19, P = 0.01) and CRP (ß, 0.31, P = 0.01). Chemerin was associated with abdominal obesity (ß, 0.33, P = 0.09) and CRP (ß, 0.29, P = 0.04), and adiponectin was associated with raised triglycerides (ß, -0.26, P = 0.05), decreased HDL-C (ß, -0.28, P = 0.06) and CRP (ß, -0.48, P = 0.01). HOMA-IR (ß, -0.39, P = 0.09) was the only predictor for omentin. MetS is associated with an altered plasma adipokines profile, with increased leptin and chemerin and decreased adiponectin circulating levels. These findings suggest a beneficial potential of adiponectin and omentin, but a detrimental potential of leptin and chemerin. Further research is needed to lighten the role of adipose tissue-derived adipokines in cardio-metabolic health.

Continuous Moderate-Intensity but Not High-Intensity Interval Training Improves Immune Function Biomarkers in Healthy Young Men.

Khammassi, M, Ouerghi, N, Said, M, Feki, M, Khammassi, Y, Pereira, B, Thivel, D, and Bouassida, A. Continuous moderate-intensity but not high-intensity interval training improves immune function biomarkers in healthy young men. J Strength Cond Res 34(1): 249-256, 2020-Effects of endurance running methods on hematological profile are still poorly known. This study aimed to compare the effects of 2 training regimes; high-intensity interval training (HIIT) and moderate-intensity continuous training (MCT) performed at the same external load on hematological biomarkers in active young men. Sixteen men aged 18-20 years were randomly assigned to HIIT or MCT group. Aerobic capacity and hematological biomarkers were assessed before and after 9 weeks of interventions. At baseline, aerobic and hematological parameters were similar for the 2 groups. After intervention, no significant change was observed in maximal aerobic velocity and estimated VO2max in both groups. Leukocyte (p < 0.01), lymphocyte (p < 0.05), neutrophil (p < 0.05), and monocyte (p < 0.01) count showed significant improvements in response to the MCT compared with the HIIT intervention. The MCT intervention favored an increase in the number of immune cells, whereas the opposite occurred as a result of the HIIT intervention. These findings suggest that MCT interventions might be superior to HIIT regimes in improving immune function in active young men.

Plasma chemerin in young untrained men: association with cardio-metabolic traits and physical performance, and response to intensive interval training.

OBJECTIVES: Chemerin is an adipose tissue-derived adipokine thought to decrease insulin sensitivity and increase cardiometabolic risk. This study aimed to assess the association of chemerin with cardiometabolic risk and physical performance and examine its response to high-intensity interval training (HIIT). METHODS: Eighteen young men have been applied a HIIT program during 8 weeks. Plasma chemerin together with several cardiometabolic factors and physical performance indices were determined before and after the training program. Plasma chemerin and insulin were assessed using immunoenzymatic methods. The homeostasis model assessment (HOMA-IR) index was calculated as an estimate of insulin resistance. RESULTS: Basal plasma chemerin was positively correlated with body mass index (r=0.782, p<0.001), body fat (r=0.767, p<0.001), total (r=0.686, p=0.002) and LDL (r=0.587, p=0.010) cholesterol, triglycerides (r=0.775, p<0.001), HOMA-IR (r=0.673, p=0.002) and C-reactive protein (r=0.765, p<0.001). With regards to physical performance, chemerin was negatively correlated with maximal oxygen uptake (r=-0.572, p=0.013) and squat jump (r=-0.627, p=0.005), but positively related to 10-m sprint (r=0.716, p=0.001) and 30-m sprint (r=0.667, p=0.002) times. HIIT program resulted in significant improvements in body composition, plasma lipids and insulin sensitivity. However, no significant change was detected for plasma chemerin in response to HIIT (134±50.7 ng/mL vs. 137±51.9 ng/mL, p=0.750). CONCLUSIONS: Basal plasma chemerin is associated with cardiometabolic health and physical performance in young men. Following HIIT, cardiometabolic health and physical performance had improved, but no significant change had occurred for plasma chemerin.

Effects of high-intensity interval training on body composition, aerobic and anaerobic performance and plasma lipids in overweight/obese and normal-weight young men.

To examine the effects of short high-intensity interval training (HIIT) on body composition, physical performance and plasma lipids in overweight/obese compared to normal-weight young men. Nine overweight/obese and nine normal-weight men (control group) aged 17 to 20 years underwent a HIIT programme three times per week for eight weeks. Body composition, indices of aerobic [maximal aerobic velocity (MAV) and maximal oxygen uptake (VO2max)] and anaerobic [squat jump (SJ), counter-movement jump (CMJ), five-jump test (FJT), 10-m and 30-m sprint] performances, as well as fasting plasma lipids, were assessed in the two groups at PRE and POST HIIT. The HIIT programme resulted in significant reductions in body mass (-1.62%, P=0.016, ES=0.11) and fat mass (-1.59%, P=0.021, ES=0.23) in obese, but not in normal-weight subjects. MAV (+5.55%, P=0.005, ES=0.60 and +2.96%, P=0.009, ES=0.82), VO2max (+5.27%, P=0.006, ES=0.63 and +2.88%, P=0.009, ES=0.41), FJT (+3.63%, P=0.005, ES=0.28 and +2.94%, P=0.009, ES=0.52), SJ (+4.92%, P=0.009, ES=0.25 and +6.94%, P=0.009, ES=0.70) and CMJ (+6.84%, P=0.014, ES=0.30 and +6.69%, P=0.002, ES=0.64) significantly increased in overweight/obese and normal-weight groups, respectively. 30-m sprint time significantly decreased in both groups (-1.77%, P=0.038, ES=0.12 and -0.72%, P=0.030, ES=0.16). Plasma total cholesterol (-11.8%, P=0.026, ES=0.96), LDL cholesterol (-11.9%, P=0.050, ES=0.77) and triglycerides (-21.3%, P=0.023, ES=1.08) significantly decreased in the obese group, but not in the normal-weight group. The eight-week HIIT programme resulted in a slight improvement in physical fitness and a significant decrease in plasma lipids in the obese. Short duration HIIT may contribute to an improved cardiometabolic profile in the obese.

A macro to micro analysis to understand performance in 100-mile ultra-marathons worldwide.

The purposes of this study were (i) to describe differences in participation in 100-mile ultra-marathons by continent; (ii) to investigate differences in performance between continents; and (iii) to identify the fastest runners by continent and country. Data from 148,169 athletes (119,408 men), aged 18-81 years, and finishers in a 100-miles ultra-marathon during 1870-2020 were investigated. Information about age, gender, origin, performance level (top three, top 10, top 100) was obtained. Kruskal-Wallis tests and linear regressions were performed. Athletes were mostly from America and Europe. A macro-analysis showed that the fastest men runners were from Africa, while the fastest women runners were from Europe and Africa. Women from Sweden, Hungary and Russia presented the best performances in the top three, top 10 and top 100. Men from Brazil, Russia and Lithuania were the fastest. The lowest performance and participation were observed for runners from Asia. In summary, in 100-miles ultra-marathon running, the majority of athletes were from America, but for both sexes and performance levels, the fastest runners were from Africa. On a country level, the fastest women were from Sweden, Hungary and Russia, while the fastest men were from Brazil, Russia and Lithuania.

Single and Combined Effects of Preferred Music and Endpoint Knowledge on Jump Performance in Basketball Players.

Both music and endpoint knowledge of exercise have been shown to independently influence exercise performance. However, whether these factors work as synergists or counteract one another during exercise is unknown. The purpose of this study was to determine the single and combined effect of listening to preferred music and types of endpoint knowledge on repeated countermovement jump (CMJ) test performance. Twenty-four (n = 24) current or previously competitive basketball players underwent CMJ testing under the following endpoint knowledge conditions: (1) unknown/no knowledge, (2) knowledge of the number of jumps, and (3) knowledge of exercise duration. For each of these, participants listened to either their preferred music or no music during the duration of testing. For the exercise portion, participants completed repeated CMJs where participants were encouraged to jump as high as possible with jump height, contact time, and flight time as outcomes. Rate of perceived exertion (RPE) and feeling scale were measured before and after exercise. The results showed that, regardless of knowledge type, preferred music resulted in a significant decrease in both contact time and flight time (F ≥ 10.4, p ≤ 0.004, and ηp2 ≥ 0.35), and a significant improvement of jump height (F = 11.36, p = 0.001, and ηp2 = 0.09) and feeling scale ratings (F = 36.9, p < 0.001, and ηp2 = 0.66) compared to no-music condition, while RPE was not significantly affected. Regardless of the presence of music, knowledge of the number of jumps and duration resulted in lower contact time (p < 0.001, 0.9 < d < 1.56) versus unknown condition during CMJs. Moreover, a significant decrease in RPE values was found during prior endpoint knowledge of number (p = 0.005; d = 0.72) and duration (p = 0.045; d = 0.63) compared to unknown condition. However, feeling scale ratings were not significantly affected. Moreover, no interactions with significance findings were found for any parameters. Overall, data suggest that listening to music and endpoint knowledge alter exercise responses in basketball players, but they do not interact with one another.

Normative reference and cut-offs values of maximal aerobic speed-20 m shuttle run test and maximal oxygen uptake for Tunisian adolescent (elite) soccer players.

This study aimed to develop reference curves of aerobic parameters of 20 m shuttle run test for Tunisian soccer players. The study was conducted in the 2022/2023 pre-season. The reference curves of the maximal aerobic speed (MAS) and the maximal oxygen uptake (VO2max) were developed according to the Lambda, Mu and Sigma (LMS) method, using data from 742 Tunisian premier league soccer players aged 11-18 years. Measured variables included: weight, height, body mass index and maximal heart rate (HRmax). HRmax was measured when the participants completed the maximal aerobic speed. VO2max was estimated using the 20 m shuttle run test protocol (speed increment every minute). Our results presented the smoothed percentiles (3rd, 10th, 25th, 50th, 75th, 90th and 97th) of MAS (km/h) and VO2max (ml/kg•min⁻1) according to age. In addition, raw data showed that VO2 max was positively correlated with age (r = 0.333; P < 0.001), height (cm) (r = 0.279; P < 0.001), weight (kg) (r = 0.266; P < 0.001), practice period (years) (r = 0.324; P < 0.001) and BMI (kg/m2) (r = 0.10; P < 0.05). However, it was negatively correlated to HRmax (bpm) (r = -0.247; P < 0.001). Only the measurements within the age group [12-12.99] are significantly higher (p < 0.001; ES = 0.63) compared with the previous age group [11-11.99]. Finally, regarding prevalence, our findings showed that 15.5 % of the players in our sample had VO2max values above the 87.7th percentile cut-off, while only 0.3 % exceeded the 99.18th percentile. The development of normative curves could help coaches and physical trainers to more accurately detect weaknesses in the aerobic performance of their players in order to sustain high-intensity repetitive actions during a soccer match.

Acute effect of hydrogen-rich water on physical, perceptual and cardiac responses during aerobic and anaerobic exercises: a randomized, placebo-controlled, double-blinded cross-over trial.

Molecular hydrogen (H2 gas) dissolved in water to produce Hydrogen-Rich Water. Hydrogen-Rich Water (HRW) is considered as ergogenic aid in different exercise modes. However, acute pre-exercise HRW ingestion effect is unclear regarding athlete performance. This study aimed at investigating acute effect of HRW ingestion on aerobic and anaerobic exercise performance. Twenty-two male amateur middle-distance runners volunteered to participate in this study. In a randomized, double-blind study design, all players ingested 500 mL of HRW or placebo (PLA) supplement 30 min before the start of the tests. Over 4 days, maximal aerobic speed of Vameval test (MAS), time to exhaustion at MAS (Tlim), squat jump (SJ), counter-movement jump (CMJ) and five jump test (5JT) were evaluated. Also, rate of perceived exertion (RPE) and peak heart rate (HRpeak) were measured during the aerobic tests. For Vameval test, HRW ingestion improved MAS, HRpeak and RPE compared with the placebo condition. For Tlim test, HRW ingestion demonstrated improvements in time to exhaustion, RPE and HRpeak. However, no significant change was observed between HW and placebo conditions in SJ, CMJ, 5JT. 500 mL of HRW can significantly improve HRpeak, time to exhaustion, RPE, with no significant effect on MAS, jumping performance in amateur endurance athletes.

Listening to music during a repeated sprint test improves performance and psychophysiological responses in healthy and physically active male adults.

BACKGROUND: It is well-documented that listening to music has the potential to improve physical performance during intense physical exercise. Less information is available on the timing of music application. This study aimed to investigate the effects of listening to preferred music during the warm up of a subsequent test or during the test on performance of repeated sprint sets (RSS) in adult males. METHODS: In a randomized cross-over design, 19 healthy males (age, 22.1 ± 1.2 years; body mass, 72.7 ± 9.3 kg; height, 1.79 ± 0.06 m; BMI, 22.6 ± 2.2 kg m-2) performed a test including 2 sets of 5*20-m repeated-sprints under one of three conditions: listening to preferred music during the test; listening to preferred music during the warm-up; or not listening to music. The assessed parameters comprised RSS performance indices, blood lactate, heart rate, the pacing strategy profile, rating of perceived exertion, and a feeling scale. RESULTS: For performance indices during set 1 of the RSS test, we found a significant decrease in total sum sequence, fast time index and fatigue index in the listening to preferred music condition compared to the no music condition (total sum sequence: p = 0.006, d = 0.93; fast time index: p = 0.003, d = 0.67; fatigue index: p < 0.001; d = 1.30) and the listening to preferred music during the warm-up condition (fast time index: p = 0.002; d = 1.15; fatigue index: p = 0.006; d = 0.74). However, there was no significant effect of listening to preferred music on physical performance during set 2 of the RSS test. Compared to the no music condition, blood lactate concentrations were higher in the listening to preferred music during the test condition (p = 0.025; d = 0.92). In addition, listening to preferred music appears not to have an effect on heart rate, the pacing strategy profile, perceived exertion, and affective responses before, during and after the RSS test. CONCLUSION: Findings from this study revealed that RSS performances were better (FT and FI indices) in the PMDT compared with the PMWU condition. Moreover, in set 1 of the RSS test, better RSS indices were found in the PMDT compared to NM condition.

Effects of High-Intensity Interval Training on Selected Adipokines and Cardiometabolic Risk Markers in Normal-Weight and Overweight/Obese Young Males-A Pre-Post Test Trial.

The study aimed to assess effects of high-intensity interval training (HIIT) on plasma adipokines and cardiometabolic markers in normal and excess weight youth. Eighteen healthy young males (18.2 ± 1.06 yrs.) were divided in normal-weight group (NWG; body mass index (BMI), 20.5 ± 1.51 kg/m2; n = 9) and excess-weight group (EWG; BMI, 30.8 ± 4.56 kg/m2; n = 9). Participants performed an eight-week HIIT program without caloric restriction. Body composition, plasma leptin, adiponectin, chemerin, omentin-1, lipids, C-reactive protein (CRP), and the homeostasis model assessment index for insulin resistance (HOMA-IR) were assessed before and after the HIIT program. The program resulted in significant increases in omentin levels (p < 0.01) in EWG (27%) and NWG (22%), but no changes in leptin, adiponectin, and chemerin in both groups. BMI (−1.62%; p = 0.015), body fat (−1.59%; p = 0.021), total cholesterol (−11.8%; p = 0.026), triglycerides (−21.3%; p = 0.023), and HOMA-IR (−31.5%; p = 0.043) decreased in EWG only. Repeated measures detected significant interaction "Time x Group" for body mass and BMI only. Eight-week HIIT program improved body composition, lipid profile, and insulin sensitivity in excess-weight individuals. It resulted in an increase in omentin levels in both normal- and excess-weight groups, but no changes in leptin, adiponectin, and chemerin. Body composition has not influenced the response of the four adipokines to HIIT.

The Effects of Verbal Encouragement and Compliments on Physical Performance and Psychophysiological Responses During the Repeated Change of Direction Sprint Test.

The general and sports psychology research is limited regarding the difference between the effects of verbal encouragement (VE) or compliment methods during high-intensity functional exercise testing. The purpose of this study was to explore the effects of VE and compliments on the performance of the repeated change-of-direction (RCOD) sprint test. A total of 36 male students in secondary school participated voluntarily in the study. They were divided equally into three homogeneous groups [VE group, compliment group (CG), and control group) and performed a standardized one repetition RCOD. The RCOD (6 × 20 m with 25-s active recovery) test consisted of a 100°change in the direction at every 4 m. Outcomes included performance indices (fast time, average time, and total time), rating of perceived exertion (RPE), and feeling scale scores. VE and the compliment increased the performance indices and RPE compared with the control group. In conclusion, VE during the exercise testing would be more beneficial for optimal performance and RPE compared with the compliment and control groups. However, the moods, during RCOD, reproduce more positively during compliment conditions than the VE and control groups.

Ghrelin Response to Acute and Chronic Exercise: Insights and Implications from a Systematic Review of the Literature.

BACKGROUND: Ghrelin is a peptide hormone predominantly produced by the stomach. It exerts a wide range of functions including stimulating growth hormone release and regulating appetite, food intake, and glucose and lipid metabolism. Since physical exercise affects all these aspects, a particular interest is accorded to the relationship between ghrelin and exercise. This systematic review aimed to summarize the current available data on the topic for a better understanding of the relationship. METHODS: An extensive computerized search was performed in the PubMed and SPORTDiscus databases for retrieving relevant articles. The search contained the following keywords: ghrelin, appetite-related peptides, gastrointestinal peptides, gastrointestinal hormones, exercise, acute exercise, chronic exercise, training, and physical activity. Studies investigating the effects of acute/chronic exercise on circulating forms of ghrelin were included. RESULTS: The initial search identified 840 articles. After screening, 80 articles were included. Despite a heterogeneity of studies and a variability of the findings, the review suggests that acute exercise suppresses acyl ghrelin production regardless of the participants and the exercise characteristics. Long- and very long-term exercise training programs mostly resulted in increased total and des-acyl ghrelin production. The increase is more noticeable in overweight/obese individuals, and is most likely due to weight loss resulting from the training program. CONCLUSION: The review suggests that exercise may impact ghrelin production. While the precise mechanisms are unclear, the effects are likely due to blood flow redistribution and weight loss for acute and chronic exercise, respectively. These changes are expected to be metabolically beneficial. Further research is needed for a better understanding of the relationship between ghrelin and exercise.

Greater effects of high- compared with moderate-intensity interval training on thyroid hormones in overweight/obese adolescent girls.

OBJECTIVES: To investigate the effects of 12-week high-intensity- (HIIT) vs. moderate-intensity-interval training (MIIT) on thyroid stimulating hormone (TSH) and thyroxine (T4) and insulin-resistance in overweight/obese adolescent girls. METHODS: Twenty four adolescent girls (age 16.5±1.36 yrs) were randomly allocated into three groups: (1) HIIT (2 blocks per session of 6-8 bouts of 30 s runs at 100-110% maximal aerobic speed (MAS), with 30 s active recovery between bouts at 50% MAS; n=8), (2) MIIT (2 blocks per session of 6-8 bouts of 30 s runs at 70-80% MAS, with 30 s active recovery between bouts at 50% MAS; n=8) and (3) control group (no exercise, n=8). Each training groups engaged in three sessions per week during three months. Anthropometric parameters, aerobic capacity, homeostasis model assessment index for insulin resistance (HOMA-IR) as well as plasma TSH and T4 levels were assessed in all subjects before- and after-training. RESULTS: Following both training programs, body mass, body mass index Z-score, waist circumference and body fat decreased, while aerobic capacity increased. However, TSH and T4 concentrations decreased only after the HIIT (-30.47%, p<0.05, ES=1.42 and -12.86%, p<0.05, ES=1.18; respectively). The HOMA-IR decreased in both training groups (-26.25%, p<0.05, ES=1.87 for MIIT and -21.72%, p<0.05, ES=2.14 for HIIT). CONCLUSION: Twelve weeks of HIIT was effective in reducing circulating TSH and T4 levels, unlike MIIT, in overweight/obese adolescent girls. These findings indicated that the stimulation of pituitary-thyroid function is more sensitive to training intensity than training duration. Further studies are needed to confirm this conclusion.

A single mega dose of vitamin D3 improves selected physical variables in vitamin D-deficient young amateur soccer players: a randomized controlled trial.

This randomized controlled trial aimed to test whether vitamin D (VD) supplementation affects measures of physical performance in VD-deficient, mildly trained children. Thirty-six recreationally soccer player boys were randomly assigned to single dose (200 000 IU) of VD3 (n = 19) or placebo (n = 17). Plasma 25-hydroxyvitamin D (25-OHD) was assessed and measures of physical performance (i.e., vertical and standing broad jumps, triple hop, 10-m and 30-m sprints, shuttle run) were performed before and 12 weeks after the loading dose. Mixed ANCOVA models were performed and effect size was estimated by partial eta squared (ηp2). Baseline 25-OHD and physical variables were equivalent in the 2 groups. Twelve weeks after VD loading, plasma 25-OHD increased and physical variables improved only in the VD group. There was a significant interaction effects for group by time for vertical jump (F = 14.9, p = 0.001, ηp2 = 0.394), triple hop jump (F = 24.2, p < 0.001, ηp2 = 0.513), 10-m (F = 4.46, p = 0.046, ηp2 = 0.162) and 30-m (F = 6.56, p = 0.017, ηp2 = 0.222) sprints, and shuttle run (F = 13.4, p = 0.001, ηp2 = 0.369). In conclusion, a single bolus of VD3 resulted in significant improvements in jumping ability, agility, and running speed in mildly trained children that are deficient in VD. The findings suggest that correcting VD deficit might be beneficial for physical performance. Novelty A mega dose of VD3 improves jumping ability, agility, and running speed in VD-deficient, mildly trained children. Effect of VD on measures of physical performance is noticeable 3 months after the loading dose.

Impact of a 12-week high-intensity interval training without caloric restriction on body composition and lipid profile in sedentary healthy overweight/obese youth.

Although High-intensity interval training (HIIT) has shown its effectiveness in improving body composition, cardio-respiratory fitness and lipid profile in obese adults, evidences remain limited in overweight/obese youth. This study was conducted to investigate the effect of a 12-week HIIT program without caloric restriction on body composition and lipid profile among young overweight/obese men. Twenty healthy obese youth were randomly allocated into two groups; experimental group (HIIT) and control group. The HIIT program consisted in 3 exercises sessions per week (30 sec of work at 100% maximal aerobic velocity [MAV]) interspersed by 30 sec of active recovery at 50% MAV, starting by 15 repetitions to reach 27 by the end of the program. Aerobic capacity (MAV and maximum oxygen uptake [VO2max]), body composition (body mass index [BMI], waist circumference [WC], and fat mass percent) and lipid profile (triglycerides [TG] and total, high-density lipoprotein [HDL] and low-density lipoprotein [LDL] cholesterol) were determined before and after the HIIT program. Following 12 weeks of HIIT, WC, BMI (P<0.01), and fat mass percent (P<0.05) were significantly decreased. MAV and VO2max were significantly improved in the HIIT group, only. Total cholesterol (P<0.05) and TG (P<0.05) decreased significantly in the HIIT group, while LDL and HDL cholesterol levels remained unchanged in both groups. HIIT may be particularly useful in overweight/obese youth to improve body composition, aerobic fitness and lipid profile.