Repetition Maximum Research Articles

Multi-Ingredient Preworkout Supplementation Compared With Caffeine and a Placebo Does Not Improve Repetitions to Failure in Resistance-Trained Women.

To determine the effect of varying doses of MIPS compared with caffeine only (C) and a placebo (PL) on resistance-training performance in trained women. Ten women (21.5 [2.3]y) completed 1-repetition-maximum tests at baseline for leg press and bench press. A within-group, double-blind, and randomized design was used to assign supplement drinks (ie,PL, C, MIPS half scoop [MIPS-H], and MIPS full scoop [MIPS-F]). Repetitions to failure were assessed at 75% and 80% to 85% of 1-repetition maximum for bench and leg press, respectively. Total performance volume was calculated as load × sets × repetitions for each session. Data were analyzed using a 1-way repeated-measures analysis of variance and reported as means and SDs. There were no differences in repetitions to failure for bench press (PL: 14.4 [3.2] repetitions, C: 14.4 [2.9] repetitions, MIPS-H: 14.2 [2.6] repetitions, MIPS-F: 15.1 [3.1] repetitions; P = .54) or leg press (PL: 13.9 [7.8] repetitions, C: 10.8 [5.9] repetitions, MIPS-H: 13.1 [7.1] repetitions, MIPS-F: 12.4 [10.7] repetitions; P = .44). Furthermore, there were no differences in total performance volume across supplements for bench press (PL: 911.2 [212.8]kg, C: 910.7 [205.5]kg, MIPS-H: 913.6 [249.3]kg, MIPS-F: 951.6 [289.6]kg; P = .39) or leg press (PL: 4318.4 [1633.6]kg, C: 3730.0 [1032.5]kg, MIPS-H: 4223.0 [1630.0]kg, MIPS-F: 4085.5 [2098.3]kg; P = .34). Overall, our findings suggest that caffeine and MIPS do not provide ergogenic benefits for resistance-trained women in delaying muscular failure.

Unrestrained Versus Vertically Restrained Loaded Countermovement Jumps: Are There Any Differences in the Components of Force Application?

The objective of this study was to compare a number of variables derived from the vertical and horizontal force components between loaded countermovement jumps performed in a Smith machine (SM modality; vertically restrained jumps) and with free weights (FW modality; unrestrained jumps). Twenty-three recreationally trained individuals, 6 women and 17 men, performed on a 3D force platform 5 maximal countermovement jump trials against 3 external loads (30%, 50%, and 70% of the SM 1-repetition maximum) using the SM and FW jumping modalities on separate sessions. The SM modality promoted greater values for virtually all the variables derived from the vertical force component (maximal force, maximal and minimum velocity, and impulse) and also shorter durations of the braking and propulsive phases. Regardless of the countermovement jump phase (braking or propulsive), the impulse directed toward the backward direction was always considerably greater for the SM compared with the FW modality. These results evidence that for recreationally trained individuals, the SM modality could be more effective to increase the general force capacity of the leg muscles due to increased external stability, while the FW modality is preferable when the orientation of force application is a crucial consideration, as it reduces the horizontal force component.

Autoregulation Does Not Provide Additional Benefits to a Mixed Session Periodized Resistance Training Program in Trained Men.

Bartolomei, S, Francesco, L, Latini, D, and Hoffman, JR. Autoregulation does not provide additional benefits to a mixed session periodized resistance training program in trained men. J Strength Cond Res 38(9): 1535-1542, 2024-The aim of this investigation was to study how autoregulation impacted training volume, performance, and muscle size on a 10-week mixed session periodized (MSP) resistance training program, characterized by the inclusion of different training foci in each session. Twenty-four resistance trained men were assigned to an autoregulated mixed session periodized (AMSP group; n = 13; age = 26.2 ± 4.9 y; body mass = 82.0 ± 8.7 kg; height = 176.8 ± 6.0 cm) or into an MSP ( n = 11; age = 24.0 ± 2.6; body mass = 81.3 ± 10.5 kg; height = 174.0 ± 5.4 cm) group. Subjects in both groups trained 5 days per week for 10 weeks and performed the same exercises. The difference between the groups consisted in the use of a perceived recovery-based scale to adjust the individual training volume in the AMSP program. Maximal strength (bench press and squat 1 repetition maximum), power (bench press throw and countermovement jump), and muscle architecture (muscle thickness [MT] of biceps brachii, trapezius, vastus lateralis and vastus medialis) were collected before and after the 10-week training period. In addition, training volume and session load were calculated for each training session. A higher total training volume ( p < 0.001) was seen in AMSP program compared with MSP program, but no differences ( p > 0.05) were noted in the average session load. No significant differences between the groups were detected for MT of both upper-body and lower-body muscles ( p's > 0.05) and lean body mass ( p = 0.681). No significant differences between the groups were detected for any strength or power measurements. Results of this study indicate that a perceived recovery-based AMSP training program was not more effective than an MSP training program for increasing muscle size and performance in resistance trained men.

Potential Benefits of Postactivation Potentiation Protocols on Tennis Performance: A Systematic Review

ABSTRACT The study aimed to provide an overview of the benefits of postactivation potentiation (PAP) protocols on tennis performance. All procedures were in accordance with the PRISMA guidelines. After an online search, 8 studies with 133 tennis players were eligible for inclusion. Results showed that a variety of methods were used to elicit PAP in tennis players, with maximal voluntary isometric contraction showing promising results in improving serve velocity (SV) by 4.6 km·h−1 (3.4 ± 4.6%; ES = 0.711) immediately after the preconditioning activity (PCA). The most favorable effects of PAP on sprinting time and maximal power were observed in resistance training exercises using squats as PCA, with loads near 60% of 1 repetition maximum (1RM), whereas the heavy load leg press warm-up demonstrated positive effects on agility and power. By contrast, negative effects on SV were observed with heavy 600-g ball throws. Despite limitations in match application because of the post-activation performance enhancement effect duration, these protocols remain beneficial for training purposes. Calculating volume load relative to 1RM can provide helpful insights for optimal PAP. However, individualizing PAP protocols based on athletes' characteristics and training status seems crucial and should be investigated in future studies.

The association between maximal muscle strength, disease severity and psychopharmacotherapy among young to middle-aged inpatients with affective disorders – a prospective pilot study

BackgroundMotor alterations and lowered physical activity are common in affective disorders. Previous research has indicated a link between depressive symptoms and declining muscle strength primarily focusing on the elderly but not younger individuals. Thus, we aimed to evaluate the relationship between mood and muscle strength in a sample of N = 73 young to middle-aged hospitalized patients (18–49 years, mean age 30.7 years) diagnosed with major depressive, bipolar and schizoaffective disorder, with a focus on moderating effects of psychopharmacotherapy. The study was carried out as a prospective observational study at a German psychiatric university hospital between September 2021 and March 2022.MethodsEmploying a standardized strength circuit consisting of computerized strength training devices, we measured the maximal muscle strength (Fmax) using three repetitions maximum across four muscle regions (abdomen, arm, back, leg) at three time points (t1-t3) over four weeks accompanied by psychometric testing (MADRS, BPRS, YRMS) and blood lipid profiling in a clinical setting. For analysis of psychopharmacotherapy, medication was split into activating (AM) and inhibiting (IM) medication and dosages were normalized by the respective WHO defined daily dose.ResultsWhile we observed a significant decrease of the MADRS score and increase of the relative total Fmax (rTFmax) in the first two weeks (t1-t2) but not later (both p < .001), we did not reveal a significant bivariate correlation between disease severity (MADRS) and muscle strength (rTFmax) at any of the timepoints. Individuals with longer disease history displayed reduced rTFmax (p = .048). IM was significantly associated with decreased rTFmax (p = .032). Regression models provide a more substantial effect of gender, age, and IM on muscle strength than the depressive episode itself (p < .001).ConclusionsThe results of the study indicate that disease severity and muscle strength are not associated in young to middle-aged inpatients with affective disorders using a strength circuit as observational measurement. Future research will be needed to differentiate the effect of medication, gender, and age on muscle strength and to develop interventions for prevention of muscle weakness, especially in younger patients with chronic affective illnesses.

Development and experimental evaluation of an instrumented constant-force bodybuilding machine. Application to the bench press exercise

In weightlifting exercise, inertial forces result in the force exerted by the athlete being variable throughout the exercise. Many new machines and training methods are intended to maintain a more constant force value. This work aims at developing and evaluating a novel type of bodybuilding machine based on a constant-force mechanism. First, the mechanical design of the proposed constant-force bodybuilding machine (CFBM) is described and its characteristic force curves are obtained by experiments. Then, the performance of an athlete in a lifting exercise carried out in a CFBM is compared to the traditional free weight (FW) exercise in a bench press session. The results demonstrate significantly smaller variations in the force curves for the CFBM than for FW, as well as the disappearance of the braking phase shown by the FW at the end of the concentric phase. Major force differences are identified for a load of 40% of the one repetition maximum (1RM), where the maximum variation in the force curve for the FW is two times higher than for FW. Differences in velocity and power curves are also reported and analized. For the 80% of 1RM the peak and mean powers are found to be 27% and 34% higher, respectively, for CFBM than for FW.

Effects of vitamin D3 supplementation on strength of lower and upper extremities in athletes: an updated systematic review and meta-analysis of randomized controlled trials.

Coaches and athletes are increasingly interested in understanding athletes' serum vitamin D levels, their impact on strength, physical performance, and athletic outcomes. Previous meta-analyses were reported with limited sample size and no significant overall effect was found. Hence, it is crucial to conduct a thorough and up-to-date systematic examination and meta-analysis to elucidate the potential advantages of supplementing with vitamin D3 in enhancing muscle strength for athletes. We performed a thorough investigation, spanning three databases (PubMed, EBSCO, and Cochrane Library), seeking randomized controlled trials (RCTs) in all languages. These trials delved into the influence of vitamin D3 supplementation on the changes of pre- and post-intervention muscle strength in healthy athletes. Our systematic examination and meta-analysis took into account serum 25(OH)D levels exceeding 30 ng/mL as a marker of adequacy. Ten RCTs, comprising 354 athletes (185 in the vitamin D3 group and 169 in the placebo group), fulfilled the inclusion criteria. During the study, 36 athletes were lost to follow-up, leaving 318 athletes (166 in the vitamin D3 group and 152 in the placebo group) with documented complete results. In comparison with the placebo group, there is a significant increase between the changes of pre- and post-intervention serum 25(OH)D levels among athletes following a period of vitamin D3 supplementation (MD 14.76, 95% CI: 8.74 to 20.77, p < 0.0001). Overall effect of four strength measurements including handgrip, one repetition maximum Bench Press (1-RM BP), vertical jump, and quadriceps contraction was not significantly improved (SMD 0.18, 95% CI: -0.02 to 0.37, p = 0.08), but there was a significant increase in quadriceps contraction (SMD 0.57, 95% CI: 0.04 to 1.11, p = 0.04). This updated meta-analysis indicates the potential benefits of vitamin D supplementation for enhancing muscle strength in athletes when analyzing its quantitatively synthesized effects. With limited available studies for the quantitative synthesis, it cannot warrant significant overall enhancements in muscle strength when athletes attain adequate serum 25(OH)D levels through supplementation.

Examining the mediating role of muscle quantity in adolescents: associations with adiposity, cardiorespiratory fitness, muscular fitness, and cardiometabolic risk factors

The aim of this study was to evaluate the mediation role of muscle quantity in the relationship between physical fitness and cardiometabolic risk factors (CMRF) in adolescents. This cross-sectional study conducted with 120 adolescents of both sexes, aged between 10 and 17 years. Body mass, height, fat mass (FM), lean mass, blood pressure, high-density lipoprotein, low-density lipoprotein, triglycerides, glucose, insulin, cardiorespiratory fitness (CRF) and 1 repetition maximum strength (1-RM) with evaluation of the leg press 45° (RM-leg), bench press (RM-bench) and arm curl (RM-arm). Body mass index z-score, appendicular skeletal muscle mass, appendicular skeletal muscle mass index, lean mass index (LMI), muscle-to-fat ratio (MFR), age at peak height velocity, and CMRF z-score were calculated. The direct relation between FM and CMRF was mediated by the LMI (26%) and inverse relation between CRF and CMRF was mediated by the LMI (26%). For girls, the direct relation between FM and CMRF was mediated by the LMI (32%); the inverse relation between CRF, RM-leg, RM-arm and CMRF was mediated by the LMI (32%, 33%, and 32%, respective). For boys, the indirect effect was not significant, indicating that LMI is not a mediator in the relation between FM, CRF, 1-RM with CMRF. The direct relation between RM-leg and CMRF was mediated by the MRF (16%). This finding evidenced the importance of promoting a healthy lifestyle to improve physical fitness levels and the quantity of muscle mass in adolescents.

Low-Load and High-Load Resistance Exercise Completed to Volitional Fatigue Induce Increases in Postexercise Metabolic Responses With More Prolonged Responses With the Low-Load Protocol.

Grisebach, D, Bornath, DPD, McCarthy, SF, Jarosz, C, and Hazell, TJ. Low-load and high-load resistance exercise completed to volitional fatigue induce increases in post-exercise metabolic responses with more prolonged responses with the low-load protocol. J Strength Cond Res 38(8): 1386-1393, 2024-Comparisons of high-load with low-load resistance training (RT) exercise have demonstrated no differences in postexercise metabolism when volume is matched. This important limitation of matching or equating volume diminishes benefits of the low-load RT protocol. Therefore, the purpose of this study was to determine the effects of acute low-load high volume and high-load low volume RT protocols completed to volitional fatigue on postexercise metabolism. Eleven recreationally active resistance-trained male subjects (24 ± 2 years; BMI: 25.3 ± 1.5 kg·m -2 ) completed 3 experimental sessions: (a) no-exercise control (CTRL); (b) RT at 30% 1 repetition maximum (1RM; 30% 1RM); and (c) RT at 90% 1RM (90% 1RM) with oxygen consumption (V̇ o2 ) measurements 2 hours postexercise. The RT sessions consisted of 3 sets of back squats, bench press, straight-leg deadlift, military press, and bent-over rows to volitional fatigue completed sequentially with 90 seconds of rest between sets and exercises. Changes were considered important if p < 0.100 with a ≥medium effect size. V̇ o2 1 hour postexercise was elevated following 30% 1RM (25%; p = 0.003, d = 1.40) and 90% 1RM (14%; p = 0.010, d = 1.15) vs. CTRL and remained elevated 2 hours postexercise following 30% 1RM (16%; p = 0.010, d = 1.15) vs. CTRL. Total O 2 consumed postexercise increased following 30% 1RM and 90% 1RM (∼17%; p < 0.044, d > 0.91) vs. CTRL. Fat oxidation was elevated 1 hour postexercise following 30% 1RM and 90% 1RM (∼155%; p < 0.001, d > 2.97) and remained elevated 2 hours postexercise following 30% 1RM compared with CTRL and 90% 1RM (∼69%; p < 0.030, d > 1.03). These data demonstrate beneficial changes to postexercise metabolism following high- and low-load RT sessions, with more prolonged effects following the low-load RT protocol completed to volitional fatigue.

Advancing Q-switched pulse generation in the 1.9 µm wavelength region using novel thulium-doped fiber gain medium and MXene Nb2CTx saturable absorber

This paper presents the first demonstration of a Q-switched Thulium-doped fiber laser (TDFL) utilizing our newly developed Thulium-doped fiber (TDF) and a MXene niobium carbide - polyethylene oxide (Nb2CTx-PEO) thin film as a gain medium and saturable absorber (SA), respectively. The TDF core glass contains 6.15 wt% Al2O3, 2.2 wt% Y2O3, 0.47 wt% Tm2O3, 2.12 wt% GeO2, 1.57 wt% HfO2 and 0.05 wt% Bi2O3 with the absorption of 30 dB/m at 1550 nm. The outcome was the realization of a stable pulsed laser operating at a central wavelength of 1888.3 nm. The Q-switched pulses exhibited a maximum repetition rate of 46.7 kHz and a minimum pulse width of 1.995 µs at a pump power of 731.41 mW. The Q-switched operation maintained a signal-to-noise ratio (SNR) of 45 dB, confirming its stability. This breakthrough highlights the laser system's potential for diverse applications, including free-space optical communication, spectroscopy, and medical fields.

Acute effects of dryland muscular endurance and maximum strength training on sprint swimming performance in young swimmers

ABSTRACT The study examined acute effects of dryland muscular endurance (ME) and maximum strength (MS) sessions on performance, physiological, and biomechanical variables during a subsequent sprint swimming session. Twenty-seven swimmers (16.5 ± 2.6 yrs) completed three experimental conditions including: i) ME, 55% of 1-repetition maximum, ii) MS, 90% of 1-repetition maximum, and iii) control (CON, no dry-land). Twenty minutes following ME, MS and CON sessions swimmers performed a 10-s tethered swimming sprint, four by 50-m (4 × 50-m), and a 100-m front crawl sprints. Performance time, blood lactate, heart rate (HR), stroke rate (SR), stroke length (SL), stroke index (SI), and stroke efficiency (ηF) were measured during 4 × 50-m and 100-m. Hand grip strength (HG), and shoulder muscles isometric strength (ISO) were measured after each session. Mean 4 × 50-m time increased in ME compared to CON by 1.7 ± 2.7% (p = 0.01), while 100-m time was similar among conditions (p > 0.05). ISO was lower after dry-land training in all conditions (p = 0.01). Tethered force, HG, HR, SR, SL, SI, and ηF were no different between conditions (p > 0.05). Dryland ME session decrease swimming performance; however, ME and MS sessions did not affect technical ability during a subsequent maximum intensity swimming.

Enhancing Training Precision: Unveiling the Barbell Velocity's Role in Tailoring the Resistance Load for the China Badminton Team.

Velocity-based resistance training is a fundamental component of sports science, offering a systematic approach to investigating the load variables of resistance exercises. This research focused on assessing the load across various resistance exercises by examining the barbell velocity during the concentric phase. The study involved 11 male athletes representing the China badminton team, who underwent 1RM testing for bench press, hip thrust, back squat, and single leg press exercises and the maximum repetition testing at load intensities of 60%, 70%, 80%, and 90% of 1RM. Simultaneously, measurements were taken of the barbell's concentric phase velocity during each exercise. The findings revealed a robust negative correlation between barbell velocity and load intensity. Furthermore, exercises engaging greater muscle strength displayed smoother fitting curves. Analysis of velocity loss rates indicated that the hip thrust exhibited a higher completion percentage compared to the back squat and the bench press. Similarly, the non-dominant leg press showed a higher completion percentage than the dominant leg press. The study emphasizes the significance of delineating barbell velocity distributions in resistance training involving large muscle groups, as well as the accurate determination of load intensity. Precise load determination can be facilitated by employing fitting curves derived from distinct movement patterns and varying load intensities. The utilization of velocity data offers a quantifiable approach to achieving targeted training outcomes.

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±10years) 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.

BLOOD FLOW RESTRICTION TRAINING OF QUADRICEP MUSCLES IN ADVANCED OSTEOARTHRITIS OF THE KNEE: A RANDOMIZED CONTROLLED STUDY

Introduction and AimQuadriceps strength is crucial for physical function in patients with knee osteoarthritis (KOA). This study aimed to investigate the effect of combining blood flow restriction (BFR) with low-intensity training (LIT) on quadricep strength in patients with advanced KOA.MethodsPatients with advanced KOA were block randomized by gender into the control or BFR group. The control group received LIT with leg press (LP) and knee extension (KE) at 30% of 1-repetition maximum (1-RM), while the BFR group underwent the same training with 70% limb occlusion.Physical function and patient-reported outcomes were assessed up to 16 weeks.ResultsA total of 42 patients were analyzed: 22 in the BFR group (9 males, 13 females) and 20 in the control group (8 males, 12 females).In the BFR group, males exhibited increased KE power from the 4th to the 16th week (p&lt;0.05) and LP power from the 4th to the 12th week (p&lt;0.05). Females in the BFR group showed increased KE power in the 4th and 12th weeks (p&lt;0.05), and LP power increased from the 4th to the 16th week (p&lt;0.05). Males also had improved TSS at the 12th week, while females had improved TSS from the 8th to the 16th week.In the control group, males did not experience an increase in quadricep power. Females, however, had increased KE power in the 4th, 12th, and 16th weeks (p&lt;0.05), and LP power from the 4th to the 12th week (p&lt;0.05). Females in the control group also had improved TSS at the 4th week.Patient-reported outcomes did not differ, and all patients tolerated the training without any dropouts or adverse events.ConclusionCombining BFR with LIT significantly improved quadricep power and physical function in both genders of KOA patients without exacerbating symptoms.

A botanical extract blend of Mangifera indica and Sphaeranthus indicus combined with resistance exercise training improves muscle strength and endurance over exercise alone in young men: a randomized, blinded, placebo-controlled trial.

Resistance exercise training (RET) is used to improve muscular strength and function. This study tested the hypothesis that RET alongside daily supplementation of a Sphaeranthus indicus and Mangifera indica extract blend (SMI) would augment bench press (BP) and leg extension (LE) strength and repetitions to failure (RTF) compared to RET alone. Ninety-nine men (age 22 ± 3) completed the trial after randomization into one of four groups: (A1) 425 mg SMI plus one RET set; (A2) 850 mg SMI plus one RET set; (P1) placebo plus one RET set; and (P2) placebo plus two RET sets. RET sets were 6-8 BP and LE repetitions at 80% of a progressive one repetition maximum (1-RM), performed 3x/week for 8 weeks. Strength and RTF were evaluated at baseline and days 14, 28, and 56 while serum values of total testosterone (TT), free testosterone (FT), and cortisol (C) values were evaluated at baseline and day 56. RET significantly (p < 0.05) increased 1-RM, RTF, and T measures above baselines regardless of group assignment, but the increases were greater in the supplemented groups. At week 8, A1 bench pressed more than P1 (71.5.5 ± 17.5 kg vs. 62.0 ± 15.3 kg, p = 0.003), while A2 pressed 13.8 ± 3.0 kg more (95% CI 5.7-21.8, p < 0.001) than P1 and 9.9 ± 13.0 kg more (95% CI 1.7-18.2, p = 0.01) than P2. Also at week 8, the mean LE 1-RM of A1 (159.4 ± 22.6 kg) and A2 (162.2 ± 22.9 kg) was greater (p < 0.05) than that of P1 (142.2 ± 25.6 kg) and P2 (146.5 ± 19.7 kg). Supplementation improved RTF, TT, and FT values over those measured in exercise alone (p < 0.05), while C levels in A2 (9.3 ± 3.8 μg/dL) were lower than P2 (11.7 ± 3.8 μg/dL, p < 0.05). Daily supplementation with SMI was well tolerated and may help optimize muscle adaptive responses to RET in men.

BENEFICIAL EFFECTS OF A COMBINED AEROBIC AND STRENGTH TRAINING PROGRAM IN PATIENTS WITH MOTOR NEURON DISEASE

INTRODUCTION &amp; AIMS Motor Neuron Disease (MND) is a neurodegenerative disease characterised by the progressive degeneration and death of motor neurons, which leads to a reduction in muscle strength and physical function. Although “Exercise as Medicine” is accepted for many diseases, the role of exercise in individuals with MND is still debated. The aim of this study was to evaluate the effect of a combined, moderate-intensity, aerobic and strength training program on aerobic capacities, strength and physical function in individuals with MND. METHODS Fifteen individuals with MND were randomly assigned to either a training (3 times/week for 12 weeks; TRAIN, n=8) or a control (continued their usual standard of care; CTRL, n=7) group. The peak aerobic capacity (VO2peak) and the maximal capacity of oxygen extraction (via Near-Infrared Spectroscopy) were evaluated during an incremental test to exhaustion on a cycle ergometer. The strength of both the lower- and upper-limb muscles was evaluated with a 1-Repetition Maximum (1RM) test on the leg press, leg extension, biceps curl, and vertical chest press. Participants also performed the “Timed Up and Go” test (TUG) and the 6-min walking test (6MWT). RESULTS The adherence to training was 86 ± 6%, and the satisfaction with the exercise program was 9.6 out of 10. VO2peak did not change significantly in both groups, but the maximal capacity of O2 extraction improved significantly in TRAIN (from 44 ± 3 to 67 ± 4%). In TRAIN, the 1RM for the leg press and leg extension increased significantly by 47 ± 8% and 50 ± 13%, respectively, while this parameter did not change in CTRL. While the 6MWT increased by 5% in TRAIN and decreased by 3% in CTRL, the change was not significant. CONCLUSION These preliminary results support the beneficial role of a combined aerobic and strength training program in individuals with MND.

Dehydration Decreases Slow Wave Sleep After Heavy Resistance Exercise

Purpose: The purpose of this study was to examine the effects of hydration status on sleep and recovery measurement before and after high volume resistance exercise. It was hypothesized that dehydration decreases sleep and recovery measurements following exercise. Methods: Eight resistance-trained men (age, 21±2 years; weight, 82.0±12.6 kg; height, 177.3±6.9 cm) performed a series of bilateral leg press and knee extensions (RE, 5 sets of 10 repetitions at 80% of 1 repetition maximum). Participants completed one trial in a euhydrated state (EUH; urine specific gravity (USG) &lt; 1.020) and the other in a dehydrated state (DEH: USG ≥ 1.020) which was separated by 2 weeks. For the DEH trial, participants were restricted from consuming fluids for 24 hours prior to the RE and were only permitted to drink 1.5 L of water post-exercise for the remainder of the day. For the EUH trial, participants were instructed to consume fluid for 24 hours prior to and 24 hours post RE to maintain euhydration. Sleep and recovery measurements were collected from a wearable sleep device that participants wore the night before (PRE) and after RE (POST). Repeated measures ANOVAs were used to identify the differences between EUH and DEH. Effect size (ES) was calculated with resulting effects identified as either small (0.2-0.49), medium (0.5-0.79), or large (&gt;0.8) effects. Results: Slow wave sleep (SWS) (POST EUH, 1.4±0.5 hr; POST DEH, 1.0±0.5 hr; ES=0.8; p=0.028) and %SWS (POST EUH, 21.8±3.7 %; POST DEH, 14.3±6.4 %; ES=1.4; p=0.016) were greater in DEH compared to EUH at the night following RE. Also, SWS decreased at POST compared to PRE in DEH (PRE DEH, 1.4±0.3hr; ES=1.0; p=0.028), but not in EUH (PRE EUH, 1.2±0.6 hr; p=0.061). Sleep duration, sleep effciency, sleep disturbance, sleep deprivation, rapid eye movement sleep (REM), %REM, light sleep, resting heart rate, and heart rate variability were not different between EUH and DEH ( p&gt;0.05). Conclusion: Dehydration decreases slow wave sleep following heavy RE, which potentially impairs recovery from exercise as SWS is important for physiological recovery. Therefore, it is critical to maintain euhydration to maximize recovery following an acute bout of RE. This study was funded by National Strength and Conditioning Association (NSCA). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Mild Osmotic Stress Alters mTOR Pathway Signaling

Increased osmotic stress reduces cell volume, thus disrupting homeostatic processes. This could impact signaling that promotes muscle growth and maintenance at rest and in response to mechanical stimuli. To date, the detrimental effect of osmotic stress on muscle protein turnover has been established in in vitro and in situ models, but the effects on muscular anabolic signaling in humans are unknown. Purpose: To examine the effect of fluid restriction (FR)-induced mild osmotic stress (plasma osmolality ≥295.0 mmol×kg−1) on muscular anabolic signaling in response to resistance exercise (RE) in trained young men. Hypothesis: We hypothesized that FR would alter the Akt/mTOR signaling. Method: RE-trained men (n=11, 21±1yr, 175.9±6.2cm, 79.2±12.3kg, 18.4±6.7% fat) completed 2 identical RE bouts either with (FR) or without (CON) fluid restriction from 24 hrs before to 3 hrs after RE. RE consisted of bilateral leg press and knee extensions (5 sets x 10 repetitions at 80% of 1 repetition maximum). The two conditions were 2-3 wks apart. Plasma osmolality (PO) was measured before (PRE), and 5 min, 15 min, 30 min, 1 hr, and 3 hrs after RE. Muscle samples were collected at PRE and 1 and 3 hrs after RE. Western blots were used to analyze contents of proteins in the mTOR signaling pathway: Akt, p-AktS473, mTOR, p-mTORS2448, p70S6K, p-p70S6KT389, rpS6, p-rpS6S240/244, eEF2, and p-eEF2T56 and normalized to Ponceau S staining (total protein). Results: Increased PO was successfully induced in FR vs. CON (condition effect, p&lt;0.0001; 299±2 vs 286±1 mmol/kg). P-AktS473 significantly (p≤0.05) increased from PRE to 1 and 3 hrs in CON, and from PRE to 1h with a return to PRE by 3h in FR (condition x time). P-AktS473 was higher at 1h and lower at 3h in FR versus CON. P-mTORS2448 increased from PRE to 1 and 3 hrs regardless of condition (main time). P-p70S6KT389 was greater in FR than CON regardless of time point (main condition). P-rpS6S240/244 increased from PRE to 1 and 3 hrs for CON and FR, and was greater for FR than CON at PRE (condition x time). Conclusion: Baseline anabolic signaling appeared elevated when individuals were subjected to mild osmotic stress. After RE, signaling through mTOR was elevated as expected when plasma was iso-osmotic, although anticipated time effects for p-p70S6K and p-eEF2 were not detected. Upstream of mTOR, activation of Akt was stronger yet shorter in duration with mild osmotic stress. Downstream of mTOR, p70S6K and rpS6 activation were greater with mild osmotic stress. While these results suggest increased anabolic signaling with mild osmotic stress, concomitant catabolic signaling should be assessed. Together, the present results and future measures will inform how conditions that confer osmotic stress, such as dehydration, may alter intramuscular protein homeostasis at rest and in response to an anabolic stimulus. This study was funded by National Strength and Conditioning Association Foundations. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Dose-Response Effects of Short-Term Rhodiola rosea Supplementation on Anaerobic Exercise Performance in Resistance-Trained Athletes: A Randomized, Crossover, Double-Blind, and Placebo-Controlled Study

Background: Rhodiola rosea (RR) has garnered attention for its potential ergogenic effects on athletic performance. The mechanisms underlying these effects are believed to involve improved energy metabolism and reduced exercise-induced oxidative stress. Methods: Twenty-seven resistance-trained individuals (13 males, 14 females; 22±3y; 170.4±10.7cm; 75.4±21.9kg) underwent three conditions in a randomized sequence: a low-dose RR (LD: 200mg/d of RR combined with 1.3g/d of maltodextrin), a high-dose RR (HD: 1.5g/d of RR), and a placebo (PL: 1.5g/d of maltodextrin), following an initial baseline (BL) assessment. Participants took supplements for seven days and a 7-day washout before transitioning to the subsequent conditions. Data were analyzed using a two-way (within-within) analysis of variance (p≤0.05) with LSD's post hoc when appropriate. Results: Participants' strength was evaluated using the one repetition maximum (1RM) test at BL and after each treatment phase. In the bench press, both RR doses exhibited significant enhancements compared to BL and PL, with weights being BL (69.6±39.7kg), PL (69.8±39.1kg), LD (72.2±41.1kg), and HD (73.4±41.4kg; p=0.001). Similarly, in the leg press, weights for both RR doses showed marked improvements over BL and PL, registering at BL (314.4±113.5kg), PL (326.2±117.0kg), LD (350.1±136.1kg), and HD (362.1±134.6kg; p&lt;0.001). Muscular endurance was further probed, with participants conducting three sets at 60% of their 1RM for both exercises. In the bench press, the HD treatment showed a significant edge over BL and PL, with weights being BL (42.5±22.9kg), PL (43.2±23.0kg), LD (43.8±23.1kg), and HD (44.7±23.6kg; p=0.007). In the leg press, both RR doses outperformed BL and PL, with weights being BL (188.6±68.2kg), PL (195.1±68.6kg), LD (209.1±80.2kg), and HD (218.6±79.1kg; p&lt;0.001). Regarding total lifting volume, both RR doses surpassed the BL measurements, with the HD regimen exceeding the PL. The volumes were BL (9792.7±4962.7kg), PL (11019.6±5389.2kg), LD (11805.1±5086.2kg), and HD (15344.8±10878.1kg; p&lt;0.001). During the bench press evaluations, a significant uptick in mean power was observed post-RR supplementation for both dosages when compared to BL and PL, with power outputs being BL (200.7±124.4W), PL (204.1±124.4W), LD (221.6±139.6W), and HD (230.5±145.9W; p=0.007). However, metrics such as peak power, average velocity, and the outcomes of the Wingate test remained statistically unchanged (p&gt;0.05). CONCLUSION: RR supplementation can enhance anaerobic performance in athletes, especially at higher doses. While it improved strength and endurance, some metrics, like peak power, remained unaffected. Further research is needed to understand RR's benefits fully. This study was self-funded, with the researchers covering all expenses. This approach ensures the research's independence from potential biases associated with external funding or grants. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

THE EFFECTIVENESS OF PROGRESSIVE RESISTANCE TRAINING IN MANAGING PROGRESSIVE SUPRANUCLEAR PALSY: A CASE STUDY

SETTING The Centre for STRONG Medicine is an outpatient multidisciplinary geriatric service at Concord Hospital, Sydney. An 82-year-old male with a primary diagnosis of Progressive Supranuclear Palsy (PSP) with cardiac and metabolic comorbidities was referred in March 2023. PSP is a rare neurological disorder that affects gait, balance, vision, and cognition. The participant mobilised with a rollator and had previously sustained vertebral and wrist fractures secondary to falls. MANAGEMENT Management was to use progressive resistance training (PRT) to combat mobility decline, prevent falls and provide education to encourage independent exercise. Initial assessment determined current health status using Falls Self Efficacy Scale (FSE-I) and Fried Frailty Phenotype (FFP) questionnaires, and measured function and strength using maximal gait speed, five times sit-to-stand (5xSTS) and one repetition maximum (1RM), respectively. FSE-I determined a high fear of falling and FFP determined frail classification. Outcomes informed the PRT exercise prescription targeting the major muscle groups for 2-3 sets of 7-9 repetitions at 70-85% 1RM progressed gradually and preformed twice weekly in a supervised group. Education regarding breathing, exercise tempo, rest, progression, and risk mitigation were provided. All outcomes were reassessed after 12-weeks of training. RESULTS Attendance was 100% (23 sessions) with improvement in all outcomes. Functional improvements included 0.25metres/second increase in maximal gait speed, 2.5 second reduction in 5xSTS, and safe mobilisation without a rollator. Strength improvements included 101% increase in 1RM leg press, 100% increase in 1RM triceps extension and 72% increase in 1RM seated row. Frailty status improved to pre-frail and fear of falling reduced. Self-reported improvements included increased steadiness and confidence exercising unsupervised. DISCUSSION Although PSP is progressive, PRT resulted in meaningful benefits in strength and function that improved daily task performance and confidence. Further research is needed to investigate the effects of PRT on PSP management in a larger cohort.