Efficacy of high-intensity interval training versus continuous training on serum myonectin and lipid outcomes in adults with metabolic syndrome: A post-hoc analysis of a clinical trial.

BACKGROUND: Myonectin is a myokine with potential effects on the lipid metabolism; however, its regulation by exercise in humans remains unclear. We aimed to compare the efficacy of high-intensity interval training low-volume (HIIT) versus moderate-intensity continuous training (MICT) on serum myonectin, serum lipids, appendicular fat and lean mass, and intramuscular lipids in humans. METHODS: Secondary analysis of a controlled, randomized, clinical trial in adults of both sexes with metabolic syndrome, who underwent a supervised, three-times/week, 12-week treadmill program. HIIT (n = 29) consisted of six intervals with one-minute, high-intensity phases at 90% of peak oxygen consumption (VO2peak) for a total of 22 min. MICT (n = 31) trained at 60% of VO2peak for 36 min. Serum myonectin was measured using a human enzyme-linked immunosorbent assay. Lipid profile was determined by enzymatic methods and free fatty acids (FFA) were measured by gas chromatography. Fat and lean mass were assessed by dual-energy X-ray absorptiometry. Intramuscular lipids were measured through proton magnetic resonance spectroscopy. RESULTS: Subjects had a mean age of 50.8±6.0 years and body mass index of 30.6±4.0 kg/m2. Compared to MICT, HIIT was not superior at increasing serum myonectin (p = 0.661) or linoleic acid (p = 0.263), reducing palmitic (p = 0.286) or stearic acid (p = 0.350), or improving lipid profile (all p>0.05), appendicular fat mass index -AFMI- (p = 0.713) or appendicular lean mass percentage -ALM- (p = 0.810). Compared to baseline, only HIIT significantly increased myonectin (p = 0.042), with a large effect size, although both interventions reduced AFMI and increased ALM with a large effect size. Lipid profile, FFA and intramuscular lipids did not change in any intervention group (p>0.05). CONCLUSIONS: Compared to MICT, HIIT low volume did not demonstrate superiority in improving serum lipids. The fact that both training types reduced AFMI without paralleled significant changes in serum myonectin suggests that this myokine may have a minor effect on short-middle-term exercise-induced fat mobilization.

Validity of Rating of Perceived Exertion Scales in Relation to Movement Velocity and Exercise Intensity During Resistance-Exercise: A Systematic Review.

CONTEXT: Movement velocity (MV) may be a valid tool to evaluate and control the load in resistance training (RT). The rating of perceived exertion (RPE) also enables practical load management. The relationship between RPE and MV may be used to monitor RT intensity. OBJECTIVE: To evaluate the validity and practicality of RPE scales related to MV and training intensity in resistance exercise. We hypothesize a positive correlation among RPE, MV, and load intensity in RT. Therefore, RPE may serve as a supplementary indicator in monitoring RT load. DATA SOURCES: Boolean algorithms were used to search several databases (SPORTDiscus, EBSCO, PubMed, Scopus, and Google Scholar). STUDY SELECTION: Studies published from 2009 to 2023 included clinical trials (randomized or not) in healthy female and male subjects that analyzed the relationship between different RPE scales and MV in basic RT exercises. STUDY DESIGN: Systematic review. LEVEL OF EVIDENCE: Level 3. RESULTS: A total of 18 studies were selected using different RPE scales with reported MV training loads. Participants included RT and untrained male and female subjects (15-31 years old). Two RPE scales (OMNI-RES and repetitions in reserve) were used. The selected studies showed moderate positive correlations among these RPE scales, MV, and training load (eg, percentage of 1-repetition maximum [%1-RM]). In addition, equations have been developed to estimate %1-RM and MV loss based on the OMNI-RES scale. CONCLUSION: Studies show that RPE scales and MV constitute a valid, economic, and practical tool for assessing RT load progression and complementing other training monitoring variables. Exercise professionals should consider familiarizing participants with RPE scales and factors that might influence the perception of exertion (eg, level of training, motivation, and environmental conditions).

Effects of a Nonlinear Program on Different Health Parameters in the Elderly.

BACKGROUND: The aim of this research was to evaluate the impact of a nonlinear training program on visceral adipose tissue (VAT) and systolic (SBP) and diastolic (DBP) blood pressure, as well as the response of biochemical parameters such as fasting plasma glucose (FPG), total cholesterol (TC), high-density cholesterol (HDL-C), low-density cholesterol (LDL-C), and triglycerides (TG). HYPOTHESIS: The nonlinear periodized program would produce greater improvements in outcomes than the linear periodized training program. STUDY DESIGN: Randomized cross-sectional design. LEVEL OF EVIDENCE: Level 3. METHODS: Older adults with no previous training experience (10 male and 8 female [age, 64 ± 2.1 years; height, 165.12 ± 7.5 cm; body mass, 72.5 ± 11.4 kg; body max index, 26.5 ± 3.2 kg/m2]) were randomized to linear (n = 9, TT) or undulating (n = 9, UT) periodization. After a 3-week familiarization period, all participants performed 3 sessions of resistance training per week; 8 weeks of training were conducted for each group. Dual x-ray absorptiometry was used to measure VAT, and SBP and DBP were measured using an OMRON M3 digital automatic blood pressure monitor. Blood samples were collected between 8:00 a.m. and 9:30 a.m. after 12-hour overnight fasting. RESULTS: Both interventions significantly (P < 0.05) decreased FPG, TC, LDL-C, and TG. A significant decrease in SBP and DBP was observed only in the UT group (P < 0.05). No significant between-group differences in outcomes were observed (P > 0.5). However, the effect size was marginally more pronounced for all outcomes in the UT group. CONCLUSION: An undulating periodization program was effective in improving VAT, TC, LDL-C, FPG, HDL-C, TG, and blood glucose levels in older adults. CLINICAL RELEVANCE: Resistance training can be programmed in an undulating or traditional way in older adults based on improvements in health parameters, considering adherence and individual preferences.

The effect of the ketogenic diet on resistance training load management: a repeated-measures clinical trial in trained participants.

BACKGROUND: The effect of low-carbohydrate high-fat dietary manipulation, such as the ketogenic diet (KD), on muscle strength assessment in resistance-training (RT) participants has focused on the one-repetition maximum test (1-RM). However, a pre-specified 1-RM value during an exercise training program disregards several confounding factors (i.e. sleep, diet, and training-induced fatigue) that affect the exerciser's "true" load and daily preparedness. We aimed to evaluate the effect of a 6-week RT program on load control-related variables in trained subjects following a KD intervention. METHODS: Fourteen resistance-trained individuals (3F, 11 M; 30.1 [6.2] years; 174.2 [7.6] cm; 75.7 [10.8] kg; BMI 24.8 [2.1] kg·m-2) completed this single-arm repeated-measures clinical trial. Load management variables included volume load, number of repetitions, perceived exertion (RPE), movement velocity loss, and exertion index. These primary outcomes were assessed weekly before, during, and at the end of a 6-week RT program that included traditional RT exercises (bench press, femoral lying down, lat pulldown, leg extension, and back squat). RESULTS: There was a significant difference in RPE between weeks (p = 0.015, W = 0.19) with a slight trend in decreasing RPE. We found differences in the volume load per week (p < 0.001; W = 0.73 and p < 0.001, W = 0.81, respectively), with an increase in the last weeks. In the control of the load based on movement velocity, we did not find significant differences between weeks (p = 0.591, W = 0.06), although significant differences were found in the effort index (p = 0.026, W = 0.17). CONCLUSIONS: A KD diet in recreational strength participants does not appear to lead to performance losses during a RT program aimed at improving body composition. However, the lack of adherence and familiarity with the ketogenic diet must be considered specially during first weeks.

Intact Short, Intermediate, and Long Skeletal Muscle Fibers Obtained by Enzymatic Dissociation of Six Hindlimb Muscles of Mice: Beyond Flexor Digitorum Brevis.

Skeletal muscle fibers obtained by enzymatic dissociation of mouse muscles are a useful model for physiological experiments. However, most papers deal with the short fibers of the flexor digitorum brevis (FDB), which restrains the scope of results dealing with fiber types, limits the amount of biological material available, and impedes a clear connection between cellular physiological phenomena and previous biochemical and dynamical knowledge obtained in other muscles. This paper describes how to obtain intact fibers from six muscles with different fiber type profiles and lengths. Using C57BL/6 adult mice, we show the muscle dissection and fiber isolation protocol and demonstrate the suitability of the fibers for Ca2+ transient studies and their morphometric characterization. The fiber type composition of the muscles is also presented. When dissociated, all muscles rendered intact, living fibers that contract briskly for more than 24 h. FDB gave short (<1 mm), peroneus digiti quarti (PDQA) and peroneus longus (PL) gave intermediate (1-3 mm), while extensor digitorum longus (EDL), extensor hallucis longus (EHL), and soleus muscles released long (3-6 mm) fibers. When recorded with the fast dye Mag-Fluo-4, Ca2+ transients of PDQA, PL, and EHL fibers showed the fast, narrow kinetics reminiscent of the morphology type II (MT-II), known to correspond to type IIX and IIB fibers. This is consistent with the fact that these muscles have over 90% of type II fibers compared with FDB (~80%) and soleus (~65%). Moving beyond FDB, we demonstrate for the first time the dissociation of several muscles, which render fibers spanning a range of lengths between 1 and 6 mm. These fibers are viable and give fast Ca2+ transients, indicating that the MT-II can be generalized to IIX and IIB fast fibers, regardless of their muscle source. These results increase the availability of models for mature skeletal muscle studies.

Profiling the Physical Performance of Young Boxers with Unsupervised Machine Learning: A Cross-Sectional Study.

Mexico City is the location with the largest number of boxers in Mexico; in fact, it is the first city in the country to open a Technological Baccalaureate in Education and Sports Promotion with a pugilism orientation. This cross-sectional study aimed to determine the physical-functional profile of applicants for admission to the baccalaureate in sports. A total of 227 young athletes (44F; 183M; 15.65 (1.79) years; 63.66 (14.98) kg; >3 years of boxing experience) participated in this study. Body mass (BM), maximal isometric handgrip (HG) strength, the height of the countermovement jump (CMJ), the velocity of straight boxing punches (PV), and the rear hand punch impact force (PIF) were measured. The young boxers were profiled using unsupervised machine learning algorithms, and the probability of superiority (ρ) was calculated as the effect size of the differences. K-Medoids clustering resulted in two sex-independent significantly different groups: Profile 1 (n = 118) and Profile 2 (n = 109). Except for BM, Profile 2 was statistically higher (p < 0.001) with a clear distinction in terms of superiority on PIF (ρ = 0.118), the PIF-to-BM ratio (ρ = 0.017), the PIF-to-HG ratio (ρ = 0.079) and the PIF-to-BM+HG ratio (ρ = 0.008). In general, strength levels explained most of the data variation; therefore, it is reasonable to recommend the implementation of tests aimed at assessing the levels of isometric and applied strength in boxing gestures. The identification of these physical-functional profiles might help to differentiate training programs during sports specialization of young boxing athletes.

Adaptogens on Depression-Related Outcomes: A Systematic Integrative Review and Rationale of Synergism with Physical Activity.

Depression is considered the most important disorder affecting mental health. The aim of this systematic integrative review was: (i) to describe the effects of supplementation with adaptogens on variables related to depression in adults; and (ii) to discuss the potential combination with physical exercise to aid planning and commissioning future clinical research. An integrative review was developed complementing the Preferred Reporting Items for Systematic reviews and Meta-Analyses statement (PROSPERO registration: CRD42021249682). A total of 41 articles met the inclusion criteria. With a Price index of 46.4%, we found that: (i) Hypericum perforatum (St. John's Wort) is the most studied and supported adaptogen (17/41 [41.46%], three systematic reviews with meta-analysis) followed by Crocus sativus L. or saffron (6/41 [14.63%], three systematic reviews with meta-analysis and two systematic reviews); (ii) it is possible that the significantly better performance of adaptogens over placebo is due to the reduction of allostatic load via the action of secondary metabolites on BDNF regulation; and, (iii) the number of studies reporting physical activity levels is limited or null for those that combine an exercise program with the consumption of adaptogens. Aware of the need for a multidisciplinary approach for depression treatment, this systematic integrative review provides an up-to-date view for supporting the use of St. John's Wort and saffron as non-pharmacological strategies while also help commissioning future research on the efficacy of other adaptogens. It also contributes to the design of future clinical research studies that evaluate the consumption of herbal extracts plus physical exercise, mainly resistance training, as a potentially safe and powerful strategy to treat depression.

Insights into Non-Exercise Physical Activity on Control of Body Mass: A Review with Practical Recommendations.

Non-exercise physical activity (NEPA), also called unstructured or informal physical activity, refers to those daily activities that require movement of the human body without planning or strict control of the physical effort made. Due to new technologies and motorized transportation devices, the general population has significantly decreased its NEPA. This increase in sedentary lifestyles, physical inactivity, and excessive energy intake is considered a risk factor for obesity, non-communicable diseases (NCDs), and all-cause mortality. Searching in PubMed/MEDLINE and Web of Science databases, a narrative review of NEPA was carried out to address its conceptualization, promotion strategies for the general population, and monitoring through wearable devices. It is strongly recommended that governmental entities, health practitioners, and the construction industry adhere to "The Global Action Plan on Physical Activity 2018-2030: More Active People for a Healthier World" and implement different salutogenic urban strategies. These strategies aim to generate environments that motivate increases in NEPA, such as cycling and walking transportation (between 5000-12,500 steps per day), and the progression to physical exercise. There is a wide variety of electronic devices for personal use, such as accelerometers, smartphone apps, or "smart clothes", that allow for the monitoring of NEPA, some with a wide range of analysis variables contributing to the estimation of total daily energy expenditure and the promotion of healthy habits. In general, the further promotion and monitoring of NEPA is required as part of a strategy to promote healthy habits sustainable over time for the prevention and control of obesity and NCDs.

Serum Levels of Myonectin Are Lower in Adults with Metabolic Syndrome and Are Negatively Correlated with Android Fat Mass.

Myonectin has shown beneficial effects on lipid regulation in murine models; therefore, it may have implications in the pathophysiology of metabolic syndrome (MS). We evaluated the relationship between serum myonectin and serum lipids, global and regional fat mass, intramuscular lipid content, and insulin resistance (IR) in adults with metabolic risk factors. This was a cross-sectional study in sedentary adults who were diagnosed with MS or without MS (NMS). Serum myonectin was quantified by enzyme-linked immunosorbent assay, lipid profile by conventional techniques, and free fatty acids (FFA) by gas chromatography. Body composition was assessed by dual-energy X-ray absorptiometry and intramuscular lipid content through proton nuclear magnetic resonance spectroscopy in the right vastus lateralis muscle. IR was estimated with the homeostatic model assessment (HOMA-IR). The MS (n = 61) and NMS (n = 29) groups were comparable in age (median (interquartile range): 51.0 (46.0-56.0) vs. 53.0 (45.5-57.5) years, p > 0.05) and sex (70.5% men vs. 72.4% women). MS subjects had lower serum levels of myonectin than NMS subjects (1.08 (0.87-1.35) vs. 1.09 (0.93-4.05) ng·mL-1, p < 0.05). Multiple linear regression models adjusted for age, sex, fat mass index and lean mass index showed that serum myonectin was negatively correlated with the android/gynoid fat mass ratio (R2 = 0.48, p < 0.01), but not with the lipid profile, FFA, intramuscular lipid content or HOMA-IR. In conclusion, serum myonectin is lower in subjects with MS. Myonectin negatively correlates with a component relevant to the pathophysiology of MS, such as the android/gynoid fat mass ratio, but not with other components such as FFA, intramuscular fat or IR.

Nutritional Strategies in the Rehabilitation of Musculoskeletal Injuries in Athletes: A Systematic Integrative Review.

It is estimated that three to five million sports injuries occur worldwide each year. The highest incidence is reported during competition periods with mainly affectation of the musculoskeletal tissue. For appropriate nutritional management and correct use of nutritional supplements, it is important to individualize based on clinical effects and know the adaptive response during the rehabilitation phase after a sports injury in athletes. Therefore, the aim of this PRISMA in Exercise, Rehabilitation, Sport Medicine and Sports Science PERSiST-based systematic integrative review was to perform an update on nutritional strategies during the rehabilitation phase of musculoskeletal injuries in elite athletes. After searching the following databases: PubMed/Medline, Scopus, PEDro, and Google Scholar, a total of 18 studies met the inclusion criteria (Price Index: 66.6%). The risk of bias assessment for randomized controlled trials was performed using the RoB 2.0 tool while review articles were evaluated using the AMSTAR 2.0 items. Based on the main findings of the selected studies, nutritional strategies that benefit the rehabilitation process in injured athletes include balanced energy intake, and a high-protein and carbohydrate-rich diet. Supportive supervision should be provided to avoid low energy availability. The potential of supplementation with collagen, creatine monohydrate, omega-3 (fish oils), and vitamin D requires further research although the effects are quite promising. It is worth noting the lack of clinical research in injured athletes and the higher number of reviews in the last 10 years. After analyzing the current quantitative and non-quantitative evidence, we encourage researchers to conduct further clinical research studies evaluating doses of the discussed nutrients during the rehabilitation process to confirm findings, but also follow international guidelines at the time to review scientific literature.

Efficacy of progressive versus severe energy restriction on body composition and strength in concurrent trained women.

PURPOSE: This study evaluated the concurrent training (CT) effect in combination with either progressive energy restriction (PER) or severe energy restriction (SER) on body composition and strength-related variables in resistance-trained women. METHODS: Fourteen women (29.5 ± 3.8 years; 23.8 ± 2.8 kg·m-2) were randomly assigned to a PER (n = 7) or SER (n = 7) group. Participants performed an 8-week CT program. Pre- and post-intervention measures of fat mass (FM) and fat-free mass (FFM) were assessed by dual-energy X-ray absorptiometry and strength-related variables were assessed through 1-repetition maximum (in the squat and bench press) and countermovement jump. RESULTS: Significant reductions in FM were observed in PER and SER (Δ = - 1.7 ± 0.4 kg; P = < 0.001; ES = - 0.39 and Δ = - 1.2 ± 0.6 kg; P = 0.002; ES = - 0.20, respectively). After correcting FFM for fat-free adipose tissue (FFAT), no significant differences for this variable were found either in PER (Δ = - 0.3 ± 0.1; P = 0.071; ES = - 0.06) or in SER (Δ = - 0.2 ± 0.1; P = 0.578; ES = - 0.04). There were no significant changes in the strength-related variables. No between-group differences were found in any of the variables. CONCLUSION: A PER has similar effects to a SER on body composition and strength in resistance-trained women performing a CT program. Given that PER is more flexible and thus may enhance dietary adherence, it might be a better alternative for FM reduction compared to SER.

Development and Validation of a Novel Waist Girth-Based Equation to Estimate Fat Mass in Young Colombian Elite Athletes (F20CA Equation): A STROSA-Based Study.

The estimation of body fat percentage (%BF) from anthropometry-related data requires population-specific equations to avoid incorrect interpretations in young athletes. Waist girth (WG) has been described as potential predictor of fat mass (FM) in several populations; however, there are no valid WG-based equations to estimate body composition in young Colombian athletes. The aim of this STandardisierte BerichtsROutine für Sekundärdaten Analysen STROSA-based study was twofold: i) to validate the relative fat mass (RFM) and its pediatric version (RFMp) compared to dual-energy x-ray absorptiometry (DXA) and ii) to develop a new equation (F20CA) to estimate the fat mass in Colombian children and adolescent elite athletes. A total of 114 young athletes that belong to the 'Team Medellín' program (58F, 56M; 51 children, 63 adolescents; 14.85 [2.38] years; 55.09 [12.16] kg; 162.38 [11.53] cm) participated in this cross-sectional study. The statistical analysis revealed a poor correlation, agreement and concordance of RFMp and RFM estimations with DXA measurements. After model specification using both Ordinary Least Square method and Bayesian analysis, the regression output revealed that sex, body mass-to-waist ratio, and waist-to-stature ratio were the statistically significant predictor variables that account for variability in FM. The new F20CA equation is expressed as FM (kg) = 5.46 ∗ (Sex) + 0.21 ∗ (BM/W [kg/m]) + 81.7 ∗ (W/Stature [cm/cm]) - 41.8 (R2 = 0.683; SEE = 2.468 kg), where sex is 0 for males and 1 for females. A moderate-to-high correlation and agreement of the F20CA was confirmed within the internal validation data set (R2 = 0.689; ICC [95%CI] = 0.805 [0.615, 0.904]; RMSE = 2.613 kg). The Bland-Altman analysis corroborated the high concordance between the reference method (DXA) and the F20CA-estimated FM (bias [95% LoA] = 1.02 [-3.77, 5.81] kg), indicating the two methods could be considered interchangeable. Even though external validation is needed, practitioners are advised to use the F20CA in young Colombian athletes with similar characteristics to those who participated in this study.

Exercise Selection and Common Injuries in Fitness Centers: A Systematic Integrative Review and Practical Recommendations.

Weight resistance training (RT) is an essential component of physical conditioning programs to improve the quality of life and physical fitness in different ages and populations. This integrative review aimed to analyze the scientific evidence on the relationship between exercise selection and the appearance of musculoskeletal injuries in physical fitness centers (PFC). The PubMed or Medline, EMBASE or Science Direct, Google Scholar and PEDro databases were selected to examine the available literature using a Boolean algorithm with search terms. The review process was performed using the five-stage approach for an integrative review and it was reported according to the PRISMA in Exercise, Rehabilitation, Sport Medicine and Sports Science (PERSiST) guidelines. A total of 39 peer-reviewed articles (Price index = 71.7%) met the inclusion criteria and evaluated the link between exercise selection and the incidence of injuries in exercisers who regularly attend PFC. Most injuries occur to the shoulders, elbows, vertebrae of the spine, and knees. Although the injury etiologies are multifactorial, the findings of the reviewed articles include the impacts of overuse, short post-exercise recovery periods, poor conditioning in the exercised body areas, frequent use of heavy loads, improper technique in certain exercises, and the abuse of performance- and image-enhancing drugs. Practical recommendations addressed to clinical exercise physiologists, exercise professionals, and health professionals are given in this paper. The exercise selection in RT programs requires professional supervision and adhering to proper lifting techniques and training habits that consider the anatomical and biomechanical patterns of the musculoskeletal structures, as well as genetic, pedagogical, and methodological aspects directly related to the stimulus-response process to mitigate the occurrence of RT-related injuries in PFC.

Development and Validation of Waist Girth-Based Equations to Evaluate Body Composition in Colombian Adults: Rationale and STROBE-Nut-Based Protocol of the F20 Project.

Waist girth (WG) represents a quick, simple, and inexpensive tool that correlates with excess of fat mass in humans; however, this measurement does not provide information on body composition. The evaluation of body composition is one of the main components in the assessment of nutritional status. Indeed, the use of anthropometry-based equations to estimate body fat and fat-free mass is a frequent strategy. Considering the lack of validation in the Colombian population, the aim of this research study (the F20 Project) is to externally validate WG-based equations (e.g., relative fat mass), and also to develop and validate new models that include WG to estimate body composition in Colombian adults compared to DXA. This cross-sectional study will be carried out following the guidelines for Strengthening the Reporting of Observational Studies in Epidemiology-Nutritional Epidemiology (STROBE-nut). Using stratified probabilistic sampling, the study population will be adults with different levels of physical activity residing in Medellín and its metropolitan area. The results of this study will not only validate the estimation performance of the current WG-based equations, but they will also develop new equations to estimate body composition in the Colombian population. This will improve professional practice in health, exercise, and sports sciences (ClinicalTrials.gov ID #NCT05450588).

A randomized open-labeled study to examine the effects of creatine monohydrate and combined training on jump and scoring performance in young basketball players.

Background: Creatine monohydrate (CrM) supplementation has been shown to be an effective and safe nutritional supplement to improve performance; however, the impact of CrM supplementation in young basketball players is less clear. This study evaluated the effects of CrM supplementation during a strength and conditioning training (SCT) program on lower-limb strength parameters and performance in under-16 (U16) basketball players. Methods: Twenty-three male U16 basketball players participated in this study (14.3 ± 0.4 years; BMI: 20.7 ± 2.2 kg∙m-2). The players were randomly assigned to either a CrM group (n = 12) that ingested 0.1 g·kg-1·day-1 of CrM or to a non-supplemented control group (n = 11, CON). The athletes participated in an 8-week SCT program consisting of two lower-limb resistance-training sessions and two plyometric sessions per week. Squat jump (SJ), drop jump (DP), countermovement jump (CMJ), and Abalakov (ABK) jump power tests as well as basketball performance (points and minutes per game) were measured before, during and/or after the intervention. Data were analyzed using a general linear model with repeated measures with independent Student's t-test pairwise comparisons. Results: The results (95% confidence interval for mean change from baseline) show that there were significant differences for all variables for CrM and CON, respectively: SJ (cm): 2.6 - 6.4, P < 0.01 and 2.2-5.1 P < 0.01; DJ (cm): 2.5-5.6, P < 0.01, and 1.8-4.4, P < 0.01; CMJ (cm): 0.3-0.8, P < 0.01, and 0.2-0.5, P < 0.01; ABK (cm): 2.8-5.5, P < 0.01 and 0.7-2.6, P = 0.003. A significant group x time interaction (p = 0.003, ηp 2 = 0.342) was observed in ABK performance. No significant group x time effects were seen in squat jump (p = 0.449, ηp 2 = 0.028), drop jump (p = 0.143, ηp 2 = 0.099), or counter movement jump (p = 0.304, ηp 2 = 0.05). A significant interaction effect was also observed in points per game (p = 0.049, ηp 2 = 0.149), while a non-significant but medium effect was seen in minutes per game (p = 0.166, ηp 2 = 0.094). Conclusions: CrM supplementation in conjunction with resistance and plyometric training increased the lower-limb ABK power and scoring performance in U16 basketball players.

Traditional and Undulating Periodization on Body Composition, Strength Levels and Physical Fitness in Older Adults.

INTRODUCTION: Undulating training has been investigated in sedentary and trained adults, but less is known about the influence of undulating training in older adults. PURPOSE: This study aimed to evaluate body composition, strength levels, and physical fitness in response to traditional or undulating training in older adults. METHODS: A controlled, double-arm trial was conducted in eighteen older adults (10 males, 8 females; 64 ± 2.1 years; 165.12 ± 7.5 cm; 72.5 ± 11.4 kg; 26.5 ± 3.2 k·gm-2) who were randomly assigned to traditional (n = 9, TT) or undulating training (n = 9, UT) for eight weeks. Dual X-ray absorptiometry was used to measure fat-free mass (FFM), fat mass (FM), and bone mineral density (BMD). Strength levels were evaluated by the handgrip strength and the one-repetition maximum in vertical chest press, rowing machine, squat, monopodal horizontal leg press, and leg extension. In addition, functional capacity was assessed using the Senior Fitness Test (SFT). Statistical analysis included mean/median comparisons to establish the difference after the intervention (paired Student's t-test or Wilcoxon test), and effect size calculations based on estimates. RESULTS: After correction for fat-free adipose tissue, a significant increase in FFM was observed in both groups, while no significant changes were found in FM and BMD. Upper- and lower-limbs strength showed significant increases in both groups, although clinical significance varied among exercises. Favorable results were seen on the cardiorespiratory fitness and strength components of the SFT in both groups. CONCLUSIONS: The 8-week UT and TT protocols are valid options for improving FFM and increasing strength and functional capacity in women and men over 60 years of age.

A Bioinformatics-Assisted Review on Iron Metabolism and Immune System to Identify Potential Biomarkers of Exercise Stress-Induced Immunosuppression.

The immune function is closely related to iron (Fe) homeostasis and allostasis. The aim of this bioinformatics-assisted review was twofold; (i) to update the current knowledge of Fe metabolism and its relationship to the immune system, and (ii) to perform a prediction analysis of regulatory network hubs that might serve as potential biomarkers during stress-induced immunosuppression. Several literature and bioinformatics databases/repositories were utilized to review Fe metabolism and complement the molecular description of prioritized proteins. The Search Tool for the Retrieval of Interacting Genes (STRING) was used to build a protein-protein interactions network for subsequent network topology analysis. Importantly, Fe is a sensitive double-edged sword where two extremes of its nutritional status may have harmful effects on innate and adaptive immunity. We identified clearly connected important hubs that belong to two clusters: (i) presentation of peptide antigens to the immune system with the involvement of redox reactions of Fe, heme, and Fe trafficking/transport; and (ii) ubiquitination, endocytosis, and degradation processes of proteins related to Fe metabolism in immune cells (e.g., macrophages). The identified potential biomarkers were in agreement with the current experimental evidence, are included in several immunological/biomarkers databases, and/or are emerging genetic markers for different stressful conditions. Although further validation is warranted, this hybrid method (human-machine collaboration) to extract meaningful biological applications using available data in literature and bioinformatics tools should be highlighted.

Velocity-Based Resistance Training on 1-RM, Jump and Sprint Performance: A Systematic Review of Clinical Trials.

Weight resistance training (RT) has been shown to positively influence physical performance. Within the last two decades, a methodology based on monitoring RT through movement velocity (also called velocity-based resistance training, VBRT) has emerged. The aim of this PRISMA-based systematic review was to evaluate the effect of VBRT programs on variables related to muscle strength (one-repetition maximum, 1-RM), and high-speed actions (vertical jump, and sprint performance) in trained subjects. The search for published articles was performed in PubMed/MEDLINE, SPORT Discus/EBSCO, OVID, Web of Science, Scopus, and EMBASE databases using Boolean algorithms independently. A total of 22 studies met the inclusion criteria of this systematic review (a low-to-moderate overall risk of bias of the analyzed studies was detected). VBRT is an effective method to improve 1-RM, vertical jump and sprint. According to the results of the analyzed studies, it is not necessary to reach high muscle failure in order to achieve the best training results. These findings reinforce the fact that it is possible to optimize exercise adaptations with less fatigue. Future studies should corroborate these findings in female population.

Profiling Physical Fitness of Physical Education Majors Using Unsupervised Machine Learning.

The academic curriculum has shown to promote sedentary behavior in college students. This study aimed to profile the physical fitness of physical education majors using unsupervised machine learning and to identify the differences between sexes, academic years, socioeconomic strata, and the generated profiles. A total of 542 healthy and physically active students (445 males, 97 females; 19.8 [2.2] years; 66.0 [10.3] kg; 169.5 [7.8] cm) participated in this cross-sectional study. Their indirect VO2max (Cooper and Shuttle-Run 20 m tests), lower-limb power (horizontal jump), sprint (30 m), agility (shuttle run), and flexibility (sit-and-reach) were assessed. The participants were profiled using clustering algorithms after setting the optimal number of clusters through an internal validation using R packages. Non-parametric tests were used to identify the differences (p < 0.05). The higher percentage of the population were freshmen (51.4%) and middle-income (64.0%) students. Seniors and juniors showed a better physical fitness than first-year students. No significant differences were found between their socioeconomic strata (p > 0.05). Two profiles were identified using hierarchical clustering (Cluster 1 = 318 vs. Cluster 2 = 224). The matching analysis revealed that physical fitness explained the variation in the data, with Cluster 2 as a sex-independent and more physically fit group. All variables differed significantly between the sexes (except the body mass index [p = 0.218]) and the generated profiles (except stature [p = 0.559] and flexibility [p = 0.115]). A multidimensional analysis showed that the body mass, cardiorespiratory fitness, and agility contributed the most to the data variation so that they can be used as profiling variables. This profiling method accurately identified the relevant variables to reinforce exercise recommendations in a low physical performance and overweight majors.