Are bodybuilding and cross-training practices dangerous for promoting orofacial injuries? A scoping review.

Bodybuilding and cross-training exercises bring health benefits. However, orofacial injuries can occur during practice. This study aimed to map, analyze, interpret, and synthesize data from studies on the main orofacial injuries resulting from bodybuilding and cross-training practices. This scoping review followed the Joanna Briggs Institute and PRISMA-ScR methods, with high-sensitivity searches in PubMed, Web of Science, Scopus, ScienceDirect, Embase, Virtual Health Library and the Google Scholar. Original scientific articles published up to May 2024 were included, which evaluated the presence of self-reported or professionally diagnosed orofacial injuries by bodybuilding and cross-training practitioners aged 18 years or older. Literature reviews, editorials, and guidelines were excluded. Tables and figures were used to map and summarize the results. Out of 30.485 potentially eligible articles, four were included. The main orofacial injuries identified in both bodybuilding and cross-training practitioners were dental damage (n = 4), temporomandibular joint (TMJ) disorders (n = 3), and traumas to oral soft tissues (n = 2) and facial soft tissues (n = 2). Dental damage and TMJ disorders were the most prevalent conditions among bodybuilding and cross-training practitioners. Therefore, dental damage and TMJ disorders were the most prevalent conditions among bodybuilding and cross-training practitioners. However, further prospective studies with more in-depth methodological designs and fewer biases are necessary.

Maintaining a Dynamic Brain: A Review of Empirical Findings Describing the Roles of Exercise, Learning, and Environmental Enrichment in Neuroplasticity from 2017-2023.

Brain plasticity, also termed neuroplasticity, refers to the brain's life-long ability to reorganize itself in response to various changes in the environment, experiences, and learning. The brain is a dynamic organ capable of responding to stimulating or depriving environments, activities, and circumstances from changes in gene expression, release of neurotransmitters and neurotrophic factors, to cellular reorganization and reprogrammed functional connectivity. The rate of neuroplastic alteration varies across the lifespan, creating further challenges for understanding and manipulating these processes to benefit motor control, learning, memory, and neural remodeling after injury. Neuroplasticity-related research spans several decades, and hundreds of reviews have been written and published since its inception. Here we present an overview of the empirical papers published between 2017 and 2023 that address the unique effects of exercise, plasticity-stimulating activities, and the depriving effect of social isolation on brain plasticity and behavior.

Mitigating skeletal muscle wasting in unloading and augmenting subsequent recovery.

Skeletal muscle wasting is the hallmark pathophysiological adaptation to unloading or disuse that demonstrates the dependency on frequent mechanical stimulation (e.g. muscle activation and subsequent loading) for homeostasis of normally load-bearing muscles. In the absence of mitigation strategies, no mammalian organism is resistant to muscle atrophy driven by unloading. Given the profound impact of unloading-induced muscle wasting on physical capacity, metabolic health and immune function; mitigation strategies during unloading and/or augmentation approaches during recovery have broad healthcare implications in settings of bed-bound hospitalization, cast immobilization and spaceflight. This topical review aims to: (1) provide a succinct, state-of-the-field summary of seminal and recent findings regarding the mechanisms of unloading-induced skeletal muscle wasting; (2) discuss unsuccessful vs. promising mitigation and recovery augmentation strategies; and (3) identify knowledge gaps ripe for future research. We focus on the rapid muscle atrophy driven by relatively short-term mechanical unloading/disuse, which is in many ways mechanistically distinct from both hypermetabolic muscle wasting and denervation-induced muscle atrophy. By restricting this discussion to mechanical unloading during which all components of the nervous system remain intact (e.g. without denervation models), mechanical loading requiring motor and sensory neural circuits in muscle remain viable targets for both mitigation and recovery augmentation. We emphasize findings in humans with comparative discussions of studies in rodents which enable elaboration of key mechanisms. We also discuss what is currently known about the effects of age and sex as biological factors, and both are highlighted as knowledge gaps and novel future directions due to limited research.

Diet Based on Pereskia aculeata Miller Flour Increases Muscle Volume and Modulates the Expression of Myokines in Mice Subjected to Resistance Training.

The study aimed to evaluate the effects of Pereskia aculeata Miller (ora-pro-nobis [OPN]) flour on body and biochemical parameters, thermogenic activity, and molecular expression of markers in the muscle tissue of mice subjected to resistance training (RT). Twelve mice were randomly assigned to two groups (n=6 animals/group): G1: control (Control) fed a standard diet + RT and G2: experimental (OPN) fed a diet based on OPN flour + RT. The RT consisted of a 6-week program using a vertical ladder combined with a fixed weight attached to the animal. Several parameters were measured, including assessment of body composition, biochemical markers, thermogenic activity, and molecular (mRNA expression of interleukin (IL)-6, fibronectin type III domain-containing protein 5 (FNDC5), peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α), nuclear respiratory factor 1 (NRF1), and mitochondrial transcription factor A (TFAM). The OPN group exhibited a decrease in body weight and visceral adiposity, higher energy expenditure, and lipid oxidation rate. In addition, it was observed an increase in muscle volume and in mRNA expression levels of IL-6, FNDC5, PGC-1α, and TFAM. These findings suggest that OPN flour could be a nutritional option to enhance performance in RT.

Measurement of Cognitive Function in Exercise Oncology Studies in Patients Treated With Chemotherapy: A Scoping Review.

Cancer-associated cognitive deficits following chemotherapy have received increased attention in clinical research. Exercise has been shown to preserve cognitive function in cancer patients, though the overall effect is mixed. Here we present a scoping review of the published literature summarizing methods used to assess cognitive function in exercise oncology trials. Methods: PubMed, PsycINFO and CINAHL databases were searched using keywords "cognition," "cancer" OR "neoplasm" OR "tumor," "chemotherapy" and "exercise" OR "physical activity." Studies eligible for inclusion include prospective studies that were published in English in peer-reviewed journals that include a method of assessing cognitive function in adult cancer patients, in which an exercise modality or method of quantifying exercise habits was evident. Studies were excluded if they included a pediatric population, patients that were not diagnosed with cancer, or were systematic/narrative/scoping reviews, protocol papers or dissertation/theses. Results: A total of 29 studies met the inclusion criteria. In total, 29 unique assessments were used to evaluate cognitive function, including patient-reported outcomes (PROs; n = 8) and objective (n = 21) methods. More than half (n = 17) of included studies relied on PROs while 12 studies utilized objective measures of cognitive function Cognitive domains of the PROs were limited in scope, focusing on memory and attention/concentration while the objective measures were broader and inclusive of multiple domains. Conclusion: The results of this review indicate that mixed approaches to evaluating cognitive function in cancer patients pose a major limitation to understanding the role of exercise as an integrative approach. The evidence demonstrates a need for more uniform assessment of cognitive function in exercise oncology trials.

Assessing the Impact of Neuromuscular Electrical Stimulation-Based Fingerboard Training versus Conventional Fingerboard Training on Finger Flexor Endurance in Intermediate to Advanced Sports Climbers: A Randomized Controlled Study.

Competitive climbers engage in highly structured training regimens to achieve peak performance levels, with efficient time management as a critical aspect. Neuromuscular electrical stimulation (NMES) training can close the gap between time-efficient conditioning training and achieving optimal prerequisites for peak climbing-specific performances. Therefore, we examined potential neuromuscular adaptations resulting from the NMFES intervention by analyzing the efficacy of twice-weekly NMES-supported fingerboard (hang board) training compared with thrice-weekly conventional fingerboard training over 7 training weeks in enhancing climbing-specific endurance among intermediate to advanced climbers. Participants were randomly divided into the NMES and control groups. Eighteen participants completed the study (14 male, 4 female; mean age: 25.7 ± 5.3 years; mean climbing experience: 6.4 ± 3.4 years). Endurance was assessed by measuring the maximal time athletes could support their body weight (hanging to exhaustion) on a 20 mm-deep ledge at three intervals: pre-, in-between- (after 4 weeks of training), and post-training (after 7 weeks of training). The findings revealed that despite the lower training volume in the NMES group, no significant differences were observed between the NMES and control groups in climbing-specific endurance. Both groups exhibited notable improvements in endurance, particularly after the in-between test. Consequently, a twice-weekly NMES-supported fingerboard training regimen demonstrated non-inferiority to a thrice-weekly conventional training routine. Incorporating NMES into fingerboard workouts could offer time-saving benefits.

Using Resistance-Band Tests to Evaluate Trunk Muscle Strength in Chronic Low Back Pain: A Test-Retest Reliability Study.

Exercise is a front-line intervention to increase functional capacity and reduce pain and disability in people with low strength levels or disorders. However, there is a lack of validated field-based tests to check the initial status and, more importantly, to control the process and make tailored adjustments in load, intensity, and recovery. We aimed to determine the test-retest reliability of a submaximal, resistance-band test to evaluate the strength of the trunk stability muscles using a portable force sensor in middle-aged adults (48 ± 13 years) with medically diagnosed chronic low back pain and healthy peers (n = 35). Participants completed two submaximal progressive tests of two resistance-band exercises (unilateral row and Pallof press), consisting of 5 s maintained contraction, progressively increasing the load. The test stopped when deviation from the initial position by compensation movements occurred. Trunk muscle strength (CORE muscles) was monitored in real time using a portable force sensor (strain gauge). Results revealed that both tests were highly reliable (intra-class correlation [ICC] > 0.901) and presented low errors and coefficients of variation (CV) in both groups. In particular, people with low back pain had errors of 14-19 N (CV = 9-12%) in the unilateral row test and 13-19 N (CV = 8-12%) in the Pallof press. No discomfort or pain was reported during or after the tests. These two easy-to-use and technology-based tests result in a reliable and objective screening tool to evaluate the strength and trunk stability in middle-aged adults with chronic low back pain, considering an error of measurement < 20 N. This contribution may have an impact on improving the individualization and control of rehabilitation or physical training in people with lumbar injuries or disorders.

Impacts of Wearable Resistance Placement on Running Efficiency Assessed by Wearable Sensors: A Pilot Study.

Wearable resistance training is widely applied to enhance running performance, but how different placements of wearable resistance across various body parts influence running efficiency remains unclear. This study aimed to explore the impacts of wearable resistance placement on running efficiency by comparing five running conditions: no load, and an additional 10% load of individual body mass on the trunk, forearms, lower legs, and a combination of these areas. Running efficiency was assessed through biomechanical (spatiotemporal, kinematic, and kinetic) variables using acceleration-based wearable sensors placed on the shoes of 15 recreational male runners (20.3 ± 1.23 years) during treadmill running in a randomized order. The main findings indicate distinct effects of different load distributions on specific spatiotemporal variables (contact time, flight time, and flight ratio, p ≤ 0.001) and kinematic variables (footstrike type, p < 0.001). Specifically, adding loads to the lower legs produces effects similar to running with no load: shorter contact time, longer flight time, and a higher flight ratio compared to other load conditions. Moreover, lower leg loads result in a forefoot strike, unlike the midfoot strike seen in other conditions. These findings suggest that lower leg loads enhance running efficiency more than loads on other parts of the body.

Concomitant administration of resveratrol and resistance training ameliorates acrylamide-induced spatial learning impairment in rats.

Objective: The present study examined effects of resistance training (RT) and resveratrol (RES) alone and together on acrylamide (AC)-induced memory impairment in rats. Materials and Methods: Animals were divided into 6 groups: (1) Control group which received normal saline intraperitoneally (ip) daily for 8 weeks; (2) Scopolamine (SCO) group which received SCO (1 mg/kg/day, ip) for 8 weeks; (3) AC group which received AC (5 mg/kg/day, ip) for 8 weeks; (4) AC + RT group which received AC (5 mg/kg/day, ip) for 8 weeks and performed RT (5 days a week for 8 weeks); (5) AC + RES group which received AC (5 mg/kg/day, ip) and RES (1 mg/kg/day, ip) for 8 weeks; and (6) AC + RT + RES group which received AC (5 mg/kg/day, ip) and RES (1 mg/kg/day, ip) for 8 weeks and performed RT (5 days a week for 8 weeks). On day 53, animal training began in the Morris Water Maze (MWM) and 24 hr after the last training, the probe test was performed. Results: RT and RES alone did not significantly affect escape latency or traveled distance increased by AC. However, concomitant RES and RT treatment significantly reduced these parameters compared to the AC group. Co-treatment with RES and RT also significantly increased the time spent in the target quadrant compared to the AC group. Lipid peroxidation was reduced in the AC+RES and AC+RT+RES groups compared to the AC group. Conclusion: It seems that daily co-treatment with RES and RT for 8 weeks ameliorates the memory-impairing effects of AC.

Bone remodeling in survivors of pediatric hematopoietic stem cell transplantation: Impact of heavy resistance training.

BACKGROUND: Early-onset osteoporosis is a frequent late effect after pediatric hematopoietic stem cell transplantation (HSCT). It remains unknown if physical training can improve bone formation in these patients, as the transplantation procedure may cause sustained dysregulation of the bone-forming osteoblast progenitor cells. OBJECTIVE: We aimed to explore the effect of resistance training on bone remodeling in long-term survivors of pediatric HSCT. PROCEDURE: In this prospective, controlled intervention study, we included seven HSCT survivors and 15 age- and sex-matched healthy controls. The participants completed a 12-week heavy load, lower extremity resistance training intervention with three weekly sessions. We measured fasting serum levels of the bone formation marker "N-terminal propeptide of type I procollagen" (P1NP), and the bone resorption marker "C-terminal telopeptide of type I collagen" (CTX). The hypothesis was planned before data collection began. The trial was registered at Clinicaltrials.gov before including the first participant, with trial registration no. NCT04922970. RESULTS: Resistance training led to significantly increased levels of fasting P1NP in both patients (from 57.62 to 114.99 ng/mL, p = .03) and controls (from 66.02 to 104.62 ng/mL, p < .001). No significant changes in fasting CTX levels were observed. CONCLUSIONS: Despite previous high-dose cytotoxic therapy, long-term survivors of pediatric HSCT respond to resistance training with improvement of bone formation, comparable to that of healthy controls. This suggests that resistance training might be a promising non-pharmacological approach to prevent the early decline in bone mass, and should be considered as part of a follow-up program to counteract long-term sequela after pediatric HSCT.

Kinetics, Kinematics, and Muscle Activity Patterns During Back Squat With Different Contributions of Elastic Resistance.

PURPOSE: Performing back squats with elastic bands has been widely used in resistance training. Although research demonstrated greater training effects obtained from adding elastic bands to the back squat, little is known regarding the optimal elastic resistance and how it affects neuromuscular performance. This study aimed to compare the force, velocity, power, and muscle activity during back squats with different contributions of elastic resistance. METHODS: Thirteen basketball players performed 3 repetitions of the back squat at 85% of 1-repetition maximum across 4 conditions: (1) total load from free weight and (2) 20%, (3) 30%, and (4) 40% of the total load from elastic band and the remaining load from free weight. The eccentric and concentric phases of the back squat were divided into upper, middle, and bottom phases. RESULTS: In the eccentric phase, mean velocity progressively increased with increasing elastic resistance, and muscle activity of the vastus medialis and rectus femoris significantly increased with the largest elastic resistance in the upper phase (P ≤ .036). In the concentric phase, mean power (P ≤ .021) and rate of force development (P ≤ .002) significantly increased with increasing elastic resistance. Furthermore, muscle activity of the vastus lateralis and vastus medialis significantly improved with the largest elastic resistance in the upper phases (P ≤ .021). CONCLUSION: Velocity, power, rate of force development, and selective muscle activity increased as the elastic resistance increased in different phases during the back-squat exercise.

Effect of warm-up protocols using lower and higher loads on multiple-set back squat volume-load.

Background: The present study aimed to investigate the effects of post-activation performance enhancement (PAPE) after three warm-up protocols on back squat performance in trained men. Methods: Fourteen resistance-trained men performed conditioning activity (CA) with high-load (HL-CA), low-load (LL-CA), or usual specific warm-up as a control (CON). HL-CA consisted of one set of three repetitions with 90% of one repetition maximum (RM); LL-CA consisted of one set of six repetitions with 45% of 1 RM performed at maximal velocity; CON involved eight repetitions with 45% of 1 RM at controlled velocity. The participant's performance was measured using the total number of repetitions and volume load (reps × load × sets). Results: There were no significant differences between warm-up for the total number of repetitions (p = 0.17) or total volume load (p = 0.15). There was no difference between conditions for the number of repetitions (main condition effect; p = 0.17); however, participants achieved a significantly higher volume load after HL-PAPE than after CON for the first set (p = 0.04). Conclusion: High or low equated-load CA used as warm-up strategies did not potentiate subsequent performance enhancement in multiple-set back squat exercise performed until muscle failure in comparison with usual warm-up.

Combined Hip and Knee Strengthening Compared With Knee Strengthening for Individuals With Lateral Patellar Dislocation: A Single-blind, Superiority, Randomized Controlled Trial.

Objective: To investigate whether a combined hip and knee muscle strengthening program is superior to a knee strengthening program for people after lateral patellar dislocation (LPD). Design: Single-blind, superiority, randomized controlled trial with 48 weeks follow-up. Setting: Physiotherapy out-patient clinic. Participants: Forty individuals aged 16 or older, with a history of non-traumatic LPD were randomized to a knee-based strengthening (KBSG) or quadriceps and hip strengthening exercise (HQSG) program (N=40). Inclusion criteria included a positive apprehension sign, pain on palpation along the medial retinaculum, and J sign. Exclusion criteria included restricted range of motion (<90° knee flexion), and traumatic or postsurgical LPD. Interventions: Concealed randomization was performed using random permuted blocks of size 4. Individuals received their corresponding exercise program according to randomization and group allocation: knee-based strengthening (n=20) or combined hip and quadriceps strengthening (n=20) twice weekly for 8 weeks over 16 appointments. Main Outcome Measures: Primary outcome was the Lysholm Knee Score. Secondary outcomes included Numerical Pain Ratings Scale (NPRS) at rest and during effort, Norwich Patellar Instability Score (NPIS), Kujala Anterior Knee Pain Scale (AKPS), Lower Extremity Functional Scale (LEFS), 4 domains of the WHOQOL-Bref, and recurrence rate. Patient-reported outcome measures were assessed from the baseline to 48 weeks. Assessments were performed by a physiotherapist who was blinded to the group allocation. Data were analyzed by using a repeated-measures ANOVA model with Tukey's post hoc test after an intention-to-treat principle. Results: At the primary time-point of 8 weeks, there were no substantial between-group differences in the Lysholm Knee Score: mean difference=-6.8 (95% CI -14.3 to 3.7); NPIS: mean difference=23.5 (95% CI 5.6 to 41.3); AKPS: mean difference=-1.54 (95% CI -8.6 to 5.6), NPRS at rest and during effort (mean difference=0.32 (95% CI -0.37 to 1); and mean difference=0.68 (95% CI -0.9 to 1.86); LEFS mean difference=-1.08 (95% CI -5.9 to 2.4), WHOQOL-Bref domains (physical health: mean difference=-0.12, (95% CI -1.26 to 1.02); psychological: mean difference=-0.32 (95% CI -2.04 to 1.4); social relations: mean difference=-0.7 (95% CI -2.2 to 0.82); environment: mean difference=0.44 (95% CI -1 to 1.9), and recurrence rate (P=.69). Conclusion: This study indicates that combined hip and knee muscle strengthening is not superior to knee-based strengthening for LPD treatment. The limitations stemming from the underpowered nature of the trial must be acknowledged, concerning the potential oversight of moderate intervention effects.

Effects of different ischemic pressures on bar velocity during the bench press exercise: A randomized crossover trial.

The main objective of this study was to evaluate the effects of different ischemic pressures applied during rest intervals on bar velocity during the bench press exercise. 10 resistance-trained males (age = 23.2 ± 2.7 years; body mass = 83.9 ± 9 kg; body height = 181 ± 5.2 cm; bench press 1 repetition maximum (1RM) = 125 ± 16.4 kg; training experience = 5.4 ± 3.4 years) participated in the study. During 4 experimental sessions, following a randomized crossover design, the subjects performed 5 sets of 3 repetitions of the bench press exercise with a load of 60% 1RM under conditions: with ischemia (50% or 80% of arterial occlusion pressure), with SHAM ischemia (20 mmHg) and without ischemia (control condition). For the ischemic conditions cuffs were applied before each set for 6.5 min and released 30 s before the start of the set as reperfusion (6.5 min ischemia + 0.5 min reperfusion). In the control condition, ischemia was not applied. The two-way repeated measures ANOVA showed no significant condition × set interaction for mean bar velocity (MV; p = 0.17) and peak bar velocity (PV; p = 0.66). There was also no main effect of condition for MV (p = 0.58) and PV (p = 0.61). The results indicate that ischemic or SHAM treatment (6.5 minutes ischemia or SHAM + 30 s reperfusion) does not affect mean and peak bar velocity during the bench press exercise regardless of the applied pressure.

Aerobic high-intensity interval training and maximal strength training in patients with unspecific musculoskeletal disorders improve V̇O2peak and maximal strength more than moderate training.

Improving peak oxygen uptake (V̇O2peak) and maximal strength are key objectives of rehabilitation for patients with unspecific musculoskeletal disorders (MSDs). Although high-intensity training yield superior outcomes for these factors, patients with MSDs may not tolerate high-intensity due to pain and fear. Therefore, we examined the effect and feasibility of incorporating aerobic high-intensity intervals (HIITs) and maximal strength training (MST) in a standard clinical rehabilitation program for patients with unspecific MSDs. 73 patients (45 ± 10 years) with MSDs partaking in a standard, public, and 4-week rehabilitation program were randomized to high-intensity training (HG: 4 × 4 minutes intervals at ∼90% of maximal heart rate; HRmax, and 4 × 4 repetitions leg press at ∼90% of 1 repetition maximum; 1RM, with maximal intended velocity) or keep todays treatment of low-to moderate-intensity training (MG: various cycling, walking, and/or running activities at ∼70%-80% of HRmax and 3 × 8 - 10 repetitions leg press at ∼75% of 1RM without maximal intended velocity). HG improved V̇O2peak (12 ± 7%) and leg press 1RM (43 ± 34%) more than moderate-intensity group (V̇O2peak; 5 ± 6%, 1RM; 19 ± 18%, both p < 0.001). We observed that no adverse events and no between-group differences in dropout rate or self-reported quality of life (both p > 0.05). There were positive correlations between improved V̇O2peak and improved physical (p = 0.024) and emotional (0.016) role functioning. We conclude that both high-intensity interval training and MST are feasible and improve V̇O2peak and maximal strength more than standard low-to moderate-intensity treatment of patients with unspecific MSDs. Our findings suggest that high-intensity training should be implemented as a part of standard clinical care of this patient population.

Caffeine Abstinence in Habituated Users: Cardiovascular Responses to Exercise With Blood Flow Restriction.

CONTEXT: Blood flow restriction resistance exercise studies often require caffeine abstinence to avoid cardiovascular effects that could change the blood flow restriction stimulus. However, effects may be attenuated for habituated users. OBJECTIVE: To compare cardiovascular responses to blood flow restriction resistance exercise when habituated users consume or abstain from caffeine. DESIGN: Thirty participants completed a 3-visit within-subject study beginning with familiarization and caffeine intake questionnaire. METHODS: Visits 2 and 3 consisted of blood flow restriction resistance exercise (3 sets bicep curls to failure, 30% 1-repetition max, 40% arterial occlusion pressure [AOP]), following participants' normal caffeine consumption (CAFF) or abstaining (ABS). AOP, systolic (SBP) and diastolic (DBP) blood pressure, and heart rate were measured preexercise and postexercise. Prevalues and preexercise to postexercise change scores for SBP, DBP, AOP (all millimeters of mercury), heart rate (in beats per minute), and repetitions were compared between conditions. Results are represented as mean (SD). RESULTS: Preexercise AOP was similar for CAFF (137.8 [14.4]) and ABS (137.1 [14.9], BF10 = 0.2), although pre-SBP was higher for CAFF (115.4 [9.8]) than ABS (112.3 [9.4], BF10 = 1.9). Pre-DBP was similar between conditions. The exercise-induced change in AOP was greater for CAFF (18.4 [11.2]) than ABS (13.2 [14.9]), though evidence was anecdotal (BF10 = 0.7). Exercise-induced changes in SBP, DBP, and heart rate were similar between conditions (all BF10 ≤ 0.40). More repetitions were completed for CAFF (63 [26]) than ABS (57 [17], BF10 = 2.1). CONCLUSIONS: The findings of this study suggest that for habituated users, maintaining daily caffeine habits will not have substantial effects on common cardiovascular variables relevant to blood flow restriction.

Influence of Menstrual Cycle and Oral Contraceptive Phases on Strength Performance, Neuromuscular Fatigue and Perceived Exertion.

The aim of the study was to assess differences in strength performance, neuromuscular fatigue and perceived exertion across phases of the menstrual cycle (MC, early follicular [eFP], late follicular [lFP] and mid-luteal phase [mLP]) and oral contraceptives (OC, active pill phase [aPP] and non-active pill phase [nPP]). Secondly, in naturally menstruating women, the influence of fluctuating serum 17ß-estradiol nd progesterone concentrations on these parameters were analysed. Thirty-four women (21 with a natural MC and 13 using OCs) completed three or two experimental sessions, respectively. Mean mean propulsive velocity (MPVmean) and total number of repetitions (REPtotal) were assessed during a power (3x8 at 60%1RM) and hypertrophy squat loading (3 sets to failure at 70%1RM), respectively. Change in bench press and squat MPV at 60%1RM in response to the loadings were used as surrogates for non-local and local fatigue, respectively. Total blood lactate accumulation (BLAA) and markers of perceived exertion were assessed in each session. No significant differences between any of the MC or OC phases were observed for MPVmean, REPtotal, non-local and local fatigue and markers of perceived exertion (all p>0.050). A higher intraindividual 17ß-estradiol concentration was significantly associated with a lower MPVmean (p=0.019). BLAA was significantly higher in lFP compared to mLP (p=0.019) and negatively associated with the intraindividual progesterone concentration (p=0.005). While 17ß-estradiol may negatively influence the MPV, it appears that fluctuations of both sex hormones across the MC and OC phases are not prominent enough to induce significant nor practically relevant changes in the assessed parameters.

Reliability of near-infrared spectroscopy in measuring muscle oxygenation during squat exercise.

Monitoring of changes in skeletal muscle oxygenation during exercise has increased in recent years. Tissue oxygenation, which is related to fatigue and muscle hypertrophy, is often measured using near-infrared spectroscopy (NIRS). OBJECTIVES: This study aimed to determine the test-retest reliability of a non-portable NIRS (NIRO200Nx) during the full-squat exercise and recovery in young healthy men. DESIGN: Twenty-five male participants (21.8 ±â€¯2.6 years) were recruited for this original research. Each participant completed an 8-repetition test with a load that elicited a velocity of 1 m·s-1. The test was conducted twice, with a 48-hour washout period between sessions. METHODS: The NIRS measured the changes of oxygenated-Hemoglobin (O2Hb), deoxygenated-Hemoglobin (HHb) and Tissue Oxygenation Index (TOI) in both Vastus Lateralis and Vastus Medialis during rest, exercise, and recovery. Coefficient of Variation (CV), Standard Error Measurement (SEM) and Intraclass Correlation Coefficient (ICC) were used to evaluate the reliability of the data. Significance was set at p < 0.05. RESULTS: The results indicated that TOI had good to acceptable absolute reliability (CVTOI = 2.7-10.2 %). A good relative relativity for the overall test was found for Vastus Medialis O2Hb (ICC = 0.851), HHb (ICC = 0.852), and TOI (ICC = 0.864), and Vastus Lateralis O2Hb (ICC = 0.898), HHb (ICC = 0.899), and TOI (ICC = 0.897). CONCLUSIONS: We conclude that NIRO200Nx is a reliable instrument for measuring muscle oxygen saturation through the TOI parameter in not-to-failure dynamic resistance exercises (1 set of 8 reps against ∼40 % 1 repetition maximum). Tissue oxygenation assessment could be a new way of individualizing exercise through dynamic resistance exercises.

EmpowerHER: A Pilot Study to Increase Physical Activity and Strength Through Powerbuilding.

Engaging in empowering exercise develops movement competency (MC) and strength and supports physical health, mental well-being, and quality of life. Powerbuilding combines powerlifting and bodybuilding to increase physical activity (PA), MC, and strength. To our knowledge, powerbuilding has not been explored as an exercise intervention. This pilot study investigated the impact of an eight-week powerbuilding intervention on women's PA, MC, strength, and empowerment. Eighteen women aged 25.1±9.8 with no powerbuilding experience participated in the intervention, meeting three times weekly for one hour. PA and MC were assessed pre- and post-intervention. Three-repetition maximum (3-RM) tests in the squat, bench press, and deadlift were completed in weeks one and eight of the intervention. Data were checked for normality; the Wilcoxon signed-rank test was used for non-normally distributed data. The McNemar test was used to analyze differences in dichotomous variables. Effect size was calculated and interpreted as follows small (r=0.1, d=0.2, ω=0.1), medium (r=0.3, d=0.5, ω=0.3), and large (r=0.5, d=0.8, ω=0.5) Total PA ([t(17)=3.52, p=0.003, d=0.83]) and participants who met the PA guidelines (Z=6.13, p=0.008, ω=0.82) increased significantly from pre- to post-intervention. Participants' MC scores improved significantly from pre- (24.3±3.5) to post-intervention (29.5±2.5; [t(17)=10.04, p<0.001; d=2.37]). Significant increases in strength were observed (squat [Z=-3.73, p<0.001, r=0.88], bench press [Z=-3.73, p<0.001, r=0.88], and deadlift [t(17)=16.41, p<0.001; d=3.87]). Empowerment in exercise scores averaged 56.3±6.6 (on a scale of 5-65). The intervention significantly increased total PA, improved MC, increased strength, and facilitated empowerment. Women's participation in powerbuilding may enhance their quality of life.

Treadmill running and mechanical overloading improved the strength of the plantaris muscle in the dystrophin-desmin double knockout (DKO) mouse.

Limited knowledge exists regarding the chronic effect of muscular exercise on muscle function in a murine model of severe Duchenne muscular dystrophy (DMD). Here we determined the effects of 1 month of voluntary wheel running (WR), 1 month of enforced treadmill running (TR) and 1 month of mechanical overloading resulting from the removal of the synergic muscles (OVL) in mice lacking both dystrophin and desmin (DKO). Additionally, we examined the effect of activin receptor administration (AR). DKO mice, displaying severe muscle weakness, atrophy and greater susceptibility to contraction-induced functional loss, were exercised or treated with AR at 1 month of age and in situ force production of lower leg muscle was measured at the age of 2 months. We found that TR and OVL increased absolute maximal force and the rate of force development of the plantaris muscle in DKO mice. In contrast, those of the tibialis anterior (TA) muscle remained unaffected by TR and WR. Furthermore, the effects of TR and OVL on plantaris muscle function in DKO mice closely resembled those in mdx mice, a less severe murine DMD model. AR also improved absolute maximal force and the rate of force development of the TA muscle in DKO mice. In conclusion, exercise training improved plantaris muscle weakness in severely affected dystrophic mice. Consequently, these preclinical results may contribute to fostering further investigations aimed at assessing the potential benefits of exercise for DMD patients, particularly resistance training involving a low number of intense muscle contractions. KEY POINTS: Very little is known about the effects of exercise training in a murine model of severe Duchenne muscular dystrophy (DMD). One reason is that it is feared that chronic muscular exercise, particularly that involving intense muscle contractions, could exacerbate the disease. In DKO mice lacking both dystrophin and desmin, characterized by severe lower leg muscle weakness, atrophy and fragility in comparison to the less severe DMD mdx model, we found that enforced treadmill running improved absolute maximal force of the plantaris muscle, while that of tibialis anterior muscle remained unaffected by both enforced treadmill and voluntary wheel running. Furthermore, mechanical overloading, a non-physiological model of chronic resistance exercise, reversed plantaris muscle weakness. Consequently, our findings may have the potential to alleviate concerns and pave the way for exploring the prescription of endurance and resistance training as a viable therapeutic approach for the treatment of dystrophic patients. Additionally, such interventions may serve in mitigating the pathophysiological mechanisms induced by physical inactivity.