Effects of heavy-load strength training during (neo-)adjuvant chemotherapy on muscle strength, muscle fiber size, myonuclei, and satellite cells in women with breast cancer.

To investigate the effects of heavy-load strength training during (neo-)adjuvant chemotherapy in women with breast cancer on muscle strength, body composition, muscle fiber size, satellite cells, and myonuclei. Women with stage I-III breast cancer were randomly assigned to a strength training group (ST, n = 23) performing supervised heavy-load strength training twice a week during chemotherapy, or a usual care control group (CON, n = 17). Muscle strength and body composition were measured and biopsies from m. vastus lateralis collected before the first cycle of chemotherapy (T0) and after chemotherapy and training (T1). Muscle strength increased significantly more in ST than in CON in chest-press (ST: +10 ± 8%, p < .001, CON: -3 ± 5%, p = .023) and leg-press (ST: +11 ± 8%, p < .001, CON: +3 ± 6%, p = .137). Both groups reduced fat-free mass (ST: -4.9 ± 4.0%, p < .001, CON: -5.2 ± 4.9%, p = .004), and increased fat mass (ST: +15.3 ± 16.5%, p < .001, CON: +16.3 ± 19.8%, p = .015) with no significant differences between groups. No significant changes from T0 to T1 and no significant differences between groups were observed in muscle fiber size. For myonuclei per fiber a non-statistically significant increase in CON and a non-statistically significant decrease in ST in type I fibers tended (p = .053) to be different between groups. Satellite cells tended to decrease in ST (type I: -14 ± 36%, p = .097, type II: -9 ± 55%, p = .084), with no changes in CON and no differences between groups. Strength training during chemotherapy improved muscle strength but did not significantly affect body composition, muscle fiber size, numbers of satellite cells, and myonuclei compared to usual care.

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.

Association between remote resistance exercises programs delivered by a smartphone application and skeletal muscle mass among elderly patients with type 2 diabetes- a retrospective real-world study.

Objective: We aimed to explore the relationship between remote resistance exercise programs delivered via a smartphone application and skeletal muscle mass among elderly patients with type 2 diabetes, utilizing real-world data. Methods: The resistance exercises were provided through Joymotion®, a web-based telerehabilitation smartphone application (Shanghai Medmotion Medical Management Co., Ltd). The primary outcome was the changes in skeletal muscle index (SMI) before and after the remote resistance exercises programs. The secondary outcomes were changes in skeletal muscle cross-sectional area (SMA), skeletal muscle radiodensity (SMD) and intermuscular adipose tissue (IMAT). Results: A total of 101 elderly patients with type 2 diabetes were analyzed. The participants had an average age of 72.9 ± 6.11 years for males and 74.4 ± 4.39 years for females. The pre- and post-intervention SMI mean (± SE) was 31.64 ± 4.14 vs. 33.25 ± 4.22 cm2/m2 in male, and 22.72 ± 3.24 vs. 24.28 ± 3.60 cm2/m2 in female respectively (all P < 0.001). Similarly, a statistically significant improvement in SMA, IMAT, and SMD for both male and female groups were also observed respectively (P < 0.001). Multiple linear regression models showed potential confounding factors of baseline hemoglobin A1c and duration of diabetes with changes in SMI in male, while hemoglobin A1c and high density lipoprotein cholesterol with changes in SMI in female. Conclusion: Remote resistance exercises programs delivered by a smartphone application were feasible and effective in helping elderly patients with type 2 diabetes to improve their skeletal muscle mass.

Effects of high-intensity interval training and resistance training on physiological parameters and performance of well-trained runners: A randomized controlled trial.

This study aimed to verify the effects of 4 weeks of high-intensity interval training (HIIT), heavy (HRT) and explosive (ERT) resistance training on aerobic, anaerobic and neuromuscular parameters and performance of well-trained runners. Twenty-six male athletes were divided into HIIT (n = 10), HRT (n = 7) and ERT (n = 9) groups. Maximal oxygen uptake (VO2max) and the corresponding velocity (vVO2max), anaerobic threshold (AT), running economy (RE), oxygen uptake kinetics, lower-body strength (1RM) and power (CMJ), and the 1500m and 5000m time-trial (TT) were determined. Improvements were observed in vVO2max (mean difference (Δ): 2.6%; effect size (ES): 0.63) with HIIT, while AT was incresead in ERT (Δ: 4.3%; ES: 0.73) and HRT (Δ: 6.9%; ES: 0.72) groups. The CMJ performance was increased in ERT (Δ: 13.8%; ES: 1.03), HRT (Δ: 6.9%; ES: 0.55) and HIIT (Δ: 5.4%; ES: 0.34), whereas 1RM increase in HRT (Δ: 38.1%; ES: 1.21) and ERT (Δ: 49.2%; ES: 0.96) groups. HIIT improved the 1500m (Δ: -2.3%; ES: -0.62) and both HRT (Δ: -1.6%; ES: -0.32) and ERT (Δ: -1.7%; ES: -0.31) the 5000m TT. Despite performance adaptations were dependent on the training characteristics, both RT and HIIT model constitute an alternative for training periodization.

Menstrual cycle patterns and their relationship with measures of well-being and perceived performance metrics in competitive and recreational resistance-trained athletes.

BACKGROUND: There is mixed evidence on how the menstrual cycle (MC) affects sports performance, with many studies showing variations in performance during different phases of the MC, while other evidence shows that the MC's effects on performance may be trivial. Therefore, this exploratory longitudinal monitoring study was designed to investigate MC characteristics and symptoms in a resistance-trained (RT) population to look for associations between measures of well-being and perceived performance metrics across the MC. METHODS: RT females reported their workout habits, perceived performance metrics, and measures of well-being while tracking their MC with detailed methods via daily check-ins in an app. RESULTS: Most MC characteristics and symptoms in the present RT population aligned with previous research on the general population. However, the frequency of irregular cycles was higher than in previous research on the general population. The amount of individual variation and within-subject cycle-to-cycle variation in MC characteristics and MC symptoms was also high. All measures of well-being were significantly associated with specific days of the MC, demonstrating a change in well-being based on the timing of the MC. Several perceived performance metrics were significantly associated with changes across the MC, while others were not. CONCLUSIONS: Overall, with the current evidence as it stands, a highly individualized approach should be taken for any training or performance considerations surrounding the MC due to the high levels of individual variation.

Low-load Resistance Exercise with Perceptually Primed Practical Blood Flow Restriction Induces Similar Motor Performance Fatigue, Physiological Changes, and Perceptual Responses Compared to Traditional Blood Flow Restriction in Males and Females.

In the recent past, practical blood flow restriction (pBFR) using non-pneumatic, usually elastic cuffs has been established as a cost-effective alternative to traditional blood flow restriction (BFR) using pneumatic cuffs, especially for training in large groups. This study investigated whether low-load resistance exercise with perceptually primed pBFR using an elastic knee wrap is suitable to induce similar motor performance fatigue as well as physiological and perceptual responses compared to traditional BFR using a pneumatic nylon cuff in males and females. In a randomized, counterbalanced cross-over study, 30 healthy subjects performed 4 sets (30-15-15-15 repetitions) of unilateral knee extensions at 20% of their one-repetition-maximum. In the pBFR condition, each individual was perceptually primed to a BFR pressure corresponding to 60% of their arterial occlusion pressure. Before and after exercise, maximal voluntary torque, maximal muscle activity, and cuff pressure-induced discomfort were assessed. Moreover, physiological (i.e., muscle activity, muscle oxygenation) and perceptual responses (i.e., effort and exercise-induced leg muscle pain) were recorded during exercise. Moderate correlations with no differences between pBFR and BFR were found regarding the decline in maximal voluntary torque and maximal muscle activity. Furthermore, no to very strong correlations between conditions, with no differences, were observed for muscle activity, muscle oxygenation, and perceptual responses during exercise sets. However, cuff pressure-induced discomfort was lower in the pBFR compared to the BFR condition. These results indicate that low-load resistance exercise combined with perceptually primed pBFR is a convenient and less discomfort inducing alternative to traditional BFR. This is especially relevant for BFR training with people who have a low cuff-induced discomfort tolerance.

Effects of Postactivation Potentiation enhacement on sprint and change-of-direction performance in athletes: A systematic review.

BACKGROUND: Training interventions like Resisted Sled Training, Complex Training, Plyometric training, and recently, Postactivation Potentiation Enhancement (PAPE) protocols are being employed by sportsmen for performance enhancement. Currently, there is no conclusive evidence on the effectiveness of the PAPE protocols and methods to integrate them into the training. The current systematic review aims to critically summarize the current evidence on PAPE protocols' effect on Sprint and Change of Direction (COD) performance in Athletes and study the influence of the Type of PAPE protocols, Recovery duration, Volumes, and loads of PAPE protocols. METHODS: A systematic computerized literature search was performed from December 2020 to June 2022 on the databases: MEDLINE (assessed by PubMed), CENTRAL (Cochrane Library Central Register of Controlled Trials), PeDro, and Science direct. The major criteria for inclusion were Athletes (Population) who performed PAPE protocol as Intervention before Sprint and/or COD assessment tests. The studies were individually assessed for Risk of Bias using EPHPP (Effective Public Health Practice Project) Tool. RESULTS: A total of sixteen studies were included. For Linear sprint, nine studies reported a significant PAPE effect whereas, six studies reported insignificant effects. Whereas, for COD performance, two studies reported insignificant results and one study reported significant CODS enhancements The recovery duration ranged from 15 s up to 16 min. CONCLUSION: PAPE protocols can be incorporated provided the recovery duration is of Moderate duration (3-8mins) or Individualized durations, using multiple sets (2-6), moderate-high loads (>85% 1-RM), type of protocol is Barbell Hip Thrust, Plyometrics or Unilateral biomechanically similar exercises to Running.

No-load resistance training as a promising alternative to stop detraining period due to covid-19 lockdown in older adults - Case report.

Restrictions to control the COVID-19 pandemic have caused older adults to stop their usual activities, including physical exercises. The novel approach of isometric no-load resistance training (NLRT) can be an interesting alternative to conventional training to oppose the harmful effects of detraining. We described the design and preliminary evaluation of an eight-week, twice-weekly NLRT program for older adults returning to strength training programs after COVID-19 lockdown. An older woman (66 years, 61.9kg, 158.5cm) and an older man (66 years, 84.1kg, 166.5cm) who were engaged in conventional strength training programs before the first COVID-19 lockdown participated in this case study. We collected muscle thickness measures using a B-mode ultrasound imaging and maximum isometric torque using an isokinetic dynamometer. Our results revealed that NLRT seems to be a good alternative to increase muscle thickness of knee and elbow flexors and extensors muscles in older adults. However, NLRT effects were inconsistent for maximum torque.

Effects of different resistance training programmings on the relative strength, body composition, anthropometric variables, and metabolic risk of elderly women.

The purpose of this study was to analyze the effect of two different programming models of resistance training (RT) on metabolic risk, anthropometric variables, and relative strength in elderly women. The research was a prospective and comparative longitudinal study with a non-probabilistic random sample. Twenty-two elderly women (64 ± 3 years) was divided into two experimental groups being the Linear programming (LP, n = 12) and Daily undulatory programming (DUP, n = 10), with 3 sessions/week for 12 weeks. Submaximal strength (10RM) was evaluated in the horizontal leg press (HL), pulldown (PD), leg curl (LC), vertical bench press (BP), and leg extension (LE). Anthropometric variables, food intake (R24h) and submaximal strength (10RM) was analyzed. Participants were initially classified as overweight or obese evaluated by body mass index (BMI) and percentual of fat mass (%FM) and with moderate to high risk to develop metabolic diseases evaluated by hip-waist ratio (HWR), waist-height ratio (WHR) and waist circumference (WC). There is no change for metabolic risk and anthropometric variables after the intervention period. There was a significant improvement for relative strength accessed by 10RM and body weight (10RM/BW), and lean body mass (10RM/LBM) (p < 0.05), with large or medium effect size for most of variables after 12 weeks of RT. As a conclusion, both programmings increased relative strength after 12 weeks of RT with attenuated change in body composition and metabolic risk in elderly women in both programming groups and all those strategies can be used in elderly women to improve strength.

Strength training improves functional capacity of individuals with chronic heart failure: Randomized clinical trial.

INTRODUCTION: Chronic heart failure (CHF) is characterized by dyspnea, exercise intolerance and impaired quality of life. Physical exercise is a key point in the treatment of these outcomes. OBJECTIVE: To evaluate the effect of 24 weeks of two different training strategies on functional capacity, muscle strength and quality of life in individuals with CHF. METHODS: The following tests and evaluations were performed before and after 24 weeks of training: exercise test, one-repetition maximum test (1- RM) and Minnesota Living with Heart Failure Questionnaire (MLHFQ). Subjects were randomized according to the modality they would perform first: aerobic training group (ATG - n=6) or strength training group (STG - n=7). RESULTS: The sample consisted of 13 individuals (10 men), aged 55 ± 12 years and a left ventricular ejection fraction (LVEF) of 38.8 ± 5.3%. There was a significant increase in V'O 2peak only in STG (STG: 26.92 ± 9.81 vs 30.52 ± 8.39 mL.kg -1 .min -1 - p=0.025; ATG: 19.60 ± 7,00 vs 22.42 ± 8.54 mL.kg -1 .min -1 - p=0.119). Both groups showed significant improvements in muscle strength (STG: 45 ± 17 vs 51 ± 20 kg - p=0.001; ATG: 38 ± 19 vs 42 ± 20 kg - p=0.012). There was no significant difference in quality of life (STG: 30 ± 18 vs 24 ± 20 - p=0.109; ATG: 36 ± 16 vs 26 ± 15 - p=0.143). CONCLUSION: The early implementation of strength training improves functional capacity and muscle strength of individuals with CHF.

No effects of post-activation performance enhancement in elite male volleyball players under complex training.

The aim of this study was to establish reliability of post-activation performance enhancement in three manners: (1) interday morning and afternoon reliability; (2) intraday morning and afternoon reliability; (3) intraday set-to-set reliability. Twelve elite male volleyball players experienced in resistance training performed four identical experimental sessions-two in the morning and two in the afternoon. During each session participants performed a mini complex training session-three sets of a conditioning activity (CA) (3 repetitions of a trap bar deadlift at 80% 1RM with 15% of accommodating resistance) and 90 s after a CA performed squat jump (SJ) with 4 min intra-set rest interval. The ANOVA with repeated measures was used to assess significance of the effect of a CA and ICC to assess reliability of measurements. The PAPE protocol was found to be ineffective to subsequently enhance JH on various occasions. Also, the results of this study suggest that the practitioners may effectively implement appropriately organized complex training as both intraday set-to-set (0.87 and 0.82 for morning sessions; 0.83 and 0.58 for afternoon sessions) and interday morning (0.67) and afternoon (0.8) reliabilities seem to be acceptable. However, introducing two CT sessions within one day is highly questionable as at the moment intraday morning and afternoon reliability is vague (0.88 and 0.48).

Effect of resistance training on quadriceps femoris muscle thickness obtained by ultrasound: A systematic review with meta-analysis.

OBJECTIVE: The present study aimed to determine the magnitude and intervention time of resistance training required to generate adaptations in the muscle thickness of the quadriceps muscle obtained by ultrasound in healthy adults. METHOD: A systematic review with meta-analysis was conducted on studies recovered from Pubmed, Web of Science, and Scopus databases up to March 2022. The study selection process was carried out by two independent researchers, with the presence of a third researcher in case of disagreements. The methodological quality of the studies was determined with the TESTEX scale, and the risk of bias analysis was determined using Cochrane's RoB 2.0 tool. The meta-analysis used the inverse of the variance with a fixed model, and the effect size was reported by the standardized mean difference (SMD) with a confidence interval of 95%. RESULTS: Ten studies were included in a meta-analysis. The overall analysis of the studies demonstrated an SMD = 0.35 [95% CI: 0.13-0.56] (P = 0.002), with a low heterogeneity of I2 = 0% (P = 0.52). No publication bias was detected using a funnel plot followed by Egger's test (P = 0.06). The degree of certainty of the meta-analysis was high using the GRADE tool. CONCLUSION: We found that resistance training can generate significant average increases of 16.6% in muscle thickness obtained by ultrasound in the quadriceps femoris muscles of healthy adults. However, the subgroup analysis showed that significant effect sizes were only observed after eight weeks of training.

The effect of resistance training in reducing hot flushes in post-menopausal women: A meta-analysis.

OBJECTIVE: The objective of this meta-analysis is to study the effect of different strengths of resistance training programs on the severity and frequency of hot flushes in postmenopausal women with vasomotor symptoms. BACKGROUND: Menopause is defined as the state in which the menstrual cycle of a biological female spontaneously comes to a halt for a period of about 1 year. Through a detailed analysis of much of the research, it is found that the resistance training program is beneficial not only for reducing the severity as well as the frequency of hot flushes in postmenopausal women. MATERIALS AND METHODS: Online research was conducted through databases such as PubMed, Cochrane Trial Register, and Google Scholar till the 20th of March 2023. The Review Manager (version 5.4.1) was used to statistically analyze the data from the studies. Studies meeting the inclusion criteria, comparing the vasomotor symptoms in resistance training groups as compared to control were used for this meta-analysis. The primary outcome of interest was the alleviation of hot flushes in the resistance training group. Random-effect model was used to pool the studies and the result was reported in SMD with 95% Confidence Interval (CI). RESULTS: 5 studies were selected for this review. Statistical analysis shows that vasomotor symptoms were more common in the control group and decreased significantly in the resistance training group after the intervention (SMD = -1.31, 95% CI: -1.85 to -0.77, p = 0.002). CONCLUSION: Resistance Training significantly affects vasomotor symptoms and can be considered for such symptoms in postmenopausal women.

Effects of low-load blood flow restriction training in healthy adult tendons: A systematic review and meta-analysis.

OBJECTIVE: To systematically review the effects of low-load blood flow restriction training (LL-BFR) on healthy adult tendons. DESIGN: A systematic review with meta-analysis. LITERATURE SEARCH: Six electronic databases were searched by two researchers. STUDY SELECTION CRITERIA: Clinical trials comparing the effects of LL-BFR to high-load resistance training (HL-RT) or low-load resistance training (LL-RT) in healthy adult tendons. DATA SYNTHESIS: Two reviewers selected the eligible clinical trials, and one reviewer exported the data. Two reviewers evaluated the study quality and risk of bias using the PEDro scale and the ROB2 scale. We performed meta-analysis where appropriate using a random-effects model. We rated the quality of evidence using GRADE. RESULTS: Six studies were eligible. We analyzed tendon cross-sectional area (CSA) and tendon stiffness as the outcomes. Across all comparisons, there was low-to moderate-quality evidence of a difference between LL-BFR and LL-RT immediately after exercise. There was high-quality evidence of no difference between LL-BFR and HL-RT in the long term. CONCLUSION: The effects of LL-BFR on the tendons depends on the time and dose of the intervention. LL-BFR could be useful to increase the CSA of the tendons in a similar or superior way to HL-RT after 8 weeks of intervention.

Time Course of Neuromuscular Fatigue During Different Resistance Exercise Loadings in Power Athletes, Strength Athletes, and Nonathletes.

ABSTRACT: Kotikangas, J, Walker, S, Peltonen, H, and Häkkinen, K. Time course of neuromuscular fatigue during different resistance exercise loadings in power athletes, strength athletes, and nonathletes. J Strength Cond Res 38(7): 1231-1242, 2024-Training background may affect the progression of fatigue and neuromuscular strategies to compensate for fatigue during resistance exercises. Thus, our aim was to examine how training background affects the time course of neuromuscular fatigue in response to different resistance exercises. Power athletes (PA, n = 8), strength athletes (SA, n = 8), and nonathletes (NA, n = 7) performed hypertrophic loading (HL, 5 × 10 × 10RM), maximal strength loadings (MSL, 7 × 3 × 3RM) and power loadings (PL, 7 × 6 × 50% of 1 repetition maximum) in back squat. Average power (AP), average velocity (VEL), surface electromyography (sEMG) amplitude (sEMGRMS), and sEMG mean power frequency (sEMGMPF) were measured within all loading sets. During PL, greater decreases in AP occurred from the beginning of SET1 to SET7 and in VEL to both SET4 and SET7 in NA compared with SA (p < 0.01, g > 1.84). During HL, there were various significant group × repetition interactions in AP within and between sets (p < 0.05, ηp2 > 0.307), but post hoc tests did not indicate significant differences between the groups (p > 0.05, g = 0.01-0.93). During MSL and HL, significant within-set and between-set decreases occurred in AP (p < 0.001, ηp2 > 0.701) and VEL (p < 0.001, ηp2 > 0.748) concurrently with increases in sEMGRMS (p < 0.01, ηp2 > 0.323) and decreases in sEMGMPF (p < 0.01, ηp2 > 0.242) in all groups. In conclusion, SA showed fatigue resistance by maintaining higher AP and VEL throughout PL. During HL, PA tended to have the greatest initial fatigue response in AP, but between-group comparisons were nonsignificant despite large effect sizes (g > 0.8). The differences in the progression of neuromuscular fatigue may be related to differing neural activation strategies between the groups, but further research confirmation is required.

A Biomechanical Comparison Between a High and Low Barbell Placement on Net Joint Moments, Kinematics, Muscle Forces, and Muscle-Specific Moments in 3 Repetition Maximum Back Squats.

ABSTRACT: Larsen, S, de Zee, M, Kristiansen, EL, and van den Tillaar, R. A biomechanical comparison between a high and low barbell placement on net joint moments, kinematics, muscle forces, and muscle-specific moments in 3 repetition maximum back squats. J Strength Cond Res 38(7): 1221-1230, 2024-This study aimed to investigate the impact of a high barbell vs. low barbell placement on net joint moments, muscle forces, and muscle-specific moments in the lower extremity joints and muscles during maximum back squats. Twelve recreationally trained men (age = 25.3 ± 2.9 years, height = 1.79 ± 7.7 m, and body mass = 82.8 ± 6.9 kg) volunteered for the study. A marker-based motion capture system and force plate data were used to calculate the net joint moments, and individual muscle forces were estimated using static optimization. Muscle forces were multiplied by their corresponding internal moment arms to determine muscle-specific moments. Statistical parametric mapping was used to analyze the effect of barbell placement as time-series data during the concentric phase. The 3 repetition maximum barbell load lifted by the subjects was 129.1 ± 13.4 kg and 130.2 ± 12.7 kg in the high bar and low bar, which were not significantly different from each other. Moreover, no significant differences were observed in net joint moments, muscle forces, or muscle-specific moments for the hip, knee, or ankle joint between the low- and high bar placements. The findings of this study suggest that barbell placement plays a minor role in lower extremity muscle forces and moment-specific moments when stance width is standardized, and barbell load lifted does not differ between barbell placements among recreationally resistance-trained men during maximal back squats. Therefore, the choice of barbell placement should be based on individual preference and comfort.

The Acute Effects of a Preload Upper-Body Power Exercise on 50-m Freestyle Performance in Youth Swimmers.

ABSTRACT: Hill, V, Patterson, S, Buckthorpe, M, and Legg, HS. The acute effects of a preload upper-body power exercise on 50-m freestyle performance in youth swimmers. J Strength Cond Res 38(7): 1295-1299, 2024-This study aimed to investigate the acute effects of a medicine ball slam and the optimal recovery time required to induce a postactivation performance enhancement (PAPE) response on 50-meter freestyle swimming performance. Twenty-four (13 female, 11 male) competitive, adolescent swimmers (mean ± SD: age, 16.7 ± 1.2 years; height, 173.3 ± 6.7 cm; mass, 63.1 ± 6.4 kg) participated in a randomized crossover study. After the PAPE intervention (3 × 5 medicine ball slams), subjects had 1-minute, 4-minute, and 8-minute recovery periods before a 50-m maximal freestyle swim. A 1-way repeated-measures ANOVA revealed that different recovery times elicited changes in 50-m performance (F = 12.12, p < 0.0005). After 4 minutes of recovery, 50-m performance was 1.6% (0.47 seconds) faster (95% confidence interval [CI] [0.17-0.77], p < 0.001). When the data were split by sex, after 4 minutes of recovery, 50-m performance was 2% (0.64 seconds) faster for women (95% CI [0.279-0.998], p < 0.001). In conclusion, an upper-body power exercise, before performance, can induce a PAPE response and enhance 50-m freestyle performance after a 4-minute recovery period.

No Effect of Interset Palm Cooling on Acute Bench Press Performance, Neuromuscular or Metabolic Responses, Following Moderate-Intensity Resistance Exercise.

ABSTRACT: McMahon, G. No effect of interset palm cooling on acute bench press performance, neuromuscular or metabolic responses, following moderate-intensity resistance exercise. J Strength Cond Res 38(7): 1213-1220, 2024-Despite the growing literature in high-intensity exercise regarding palm cooling, the acute effects of palm cooling on exercise performance indices, neuromuscular and metabolic responses, have not been described during moderate-intensity resistance exercise. Nine (age, 22 ± 1 year; mass, 80.8 ± 16.2 kg; height, 1.80 ± 0.11 m) healthy, male (n = 7) and female (n = 2) resistance-trained subjects performed 4 sets of bench press to failure at 60% 1 repetition maximum with 3-minute passive recovery. Subjects were randomly allocated to either the cooling (COL; 2 minutes of cooling at 10 °C) or the control (passive rest; CON) condition separated by 1 week between the conditions. Exercise performance (volume load, repetitions, barbell velocity), muscle activation, blood lactate, and rate of perceived exertion were assessed. Despite changes across the variables during the resistance exercise sessions, there were no statistical differences (p > 0.05) in any of the performance, neuromuscular or physiological responses, between the 2 experimental conditions, despite palm temperature being significantly (p < 0.001) reduced in the cooling condition compared with control throughout. Therefore, based on the results of this study, palm cooling does not enhance acute moderate-intensity resistance exercise.

Relationships Between Strength and Power With the 74.84-kg (165-lb) and 90.72-kg (200-lb) Body Drags.

ABSTRACT: Moreno, MR, Dawes, JJ, Orr, RM, Dulla, JM, and Lockie, RG. Relationships between strength and power with the 74.84-kg (165-lb) and 90.72-kg (200-lb) body drags. J Strength Cond Res 38(7): 1305-1313, 2024-A body drag is an essential job task in law enforcement. It is purported that strength and power should contribute to this task, but there has been limited analysis. This study examined strength (1-repetition maximum hexagonal bar deadlift [1RM HBD]) and power (vertical jump [VJ], standing broad jump [SBJ]) relationships with the 74.84-kg and 90.72-kg body drags. Forty-three civilians (24 men and 19 women) completed the SBJ, VJ, and 1RM HBD in 1 session. Peak anaerobic power measured in watts (PAPw) was derived from the VJ. Relative measures were calculated from the SBJ, PAPw, and HBD. In another 2 sessions, subjects completed 74.84-kg and 90.72-kg drags in a counterbalanced order using 2 techniques: standard and adapted (time taken to pick dummy up from ground included in time). Independent samples t-tests compared the sexes and subjects who could or could not complete all drags. Partial correlations and stepwise regression, both controlling for sex, examined relationships between strength and power and the drags. In general, men outperformed women in almost all tests (p ≤ 0.024). Thirty-five subjects completed all drags and were stronger and more powerful than subjects who could not (p ≤ 0.011). The SBJ correlated with the 74.84-kg standard (r = -0.355) and 90.72-kg adapted (r = -0.373) drags; the VJ correlated with the 74.84-kg standard drag (r = -0.356). Peak anaerobic power measured in watts and 1RM HBD correlated with all drags (r = -0.382 to -0.668); PAPw was involved in all significant predictive relationships (explained variance = 34-62%). Absolute strength and power training should be a focus for recruits to enhance their ability to perform dragging tasks, especially with heavier masses.

Can the Velocity of a 1RM Hang Power Clean Be Used to Estimate a 1RM Hang High Pull?

ABSTRACT: Suchomel, TJ, Techmanski, BS, Kissick, CR, and Comfort, P. Can the velocity of a 1RM hang power clean be used to estimate a 1RM hang high pull? J Strength Cond Res 38(7): 1321-1325, 2024-The purpose of this study was to estimate the 1-repetition maximum hang high pull (1RM HHP) using the peak barbell velocity of a 1RM hang power clean (HPC). Fifteen resistance-trained men (age = 25.5 ± 4.5 years, body mass = 88.3 ± 15.4 kg, height = 176.1 ± 8.5 cm, relative 1RM HPC = 1.3 ± 0.2 kg·kg-1) with previous HPC experience participated in 2 testing sessions that included performing a 1RM HPC and HHP repetitions with 20, 40, 60, and 80% of their 1RM HPC. Peak barbell velocity was measured using a linear position transducer during the 1RM HPC and HHP repetitions performed at each load. The peak barbell velocity achieved during the 1RM HPC was determined as the criterion value for a 1RM performance. Subject-specific linear regression analyses were completed using slope-intercept equations created from the peak velocity of the 1RM HPC and the peak barbell velocities produced at each load during the HHP repetitions. The peak barbell velocity during the 1RM HPC was 1.74 ± 0.30 m·s-1. The average load-velocity profile showed that the estimated 1RM HHP of the subjects was 98.0 ± 19.3% of the 1RM HPC. Although a 1RM HHP value may be estimated using the peak barbell velocity during the HPC, strength and conditioning practitioners should avoid this method because of the considerable variation within the measurement. Additional research examining different methods of load prescription for weightlifting pulling derivatives is needed.