Maximal Dynamic Strength Research Articles

Evaluation of psychological measures for the assessment of recovery and stress during a shock-microcycle in strength and high-intensity interval training

The aim of this paper was a) to analyse the intraindividual change and criterion sensitivity of the Acute Recovery and Stress Scale (ARSS) and its abridged version the Short Recovery and Stress Scale (SRSS) in response to a 6-day microcycle of intensified strength training (STM) and high-intensity interval training (HIIT) in comparison with the change in the criterion measures maximal dynamic strength (estimated 1 repetition maximum [1RMest]; STM) or repeated sprint ability (RSA; HIIT), and b) to compare descriptively the results of the subjective measures with earlier reported physiological and performance markers of the same study. Participants were 23 (STM; 23.7±2.0years) and 22 (HIIT; 22.8±2.6) well-trained athletes who completed 11 training sessions over 6days to induce functional overload. The ARSS scales and the SRSS items were assessed every morning and the criterion measures 3 times (pre, post1, post2). Changes were analysed over the entire period and from pre- to post training as well as after 72-h of recovery. ARSS and SRSS ratings and the criterion measures presented deteriorations upon the intensive training as well as improvements following the recovery period. The overall and physical-related scales/items demonstrated large change effects in response to the physical stress stimulus in both training protocols (Cohen’s d between |0.92| and |2.04|). The mental-related scales/items described moderate to large change effects (d=|0.30| to |0.73|) and the emotional-related scales/items small to moderate change effects (d=|0.07| to |0.51|). The sensitivity analyses revealed the highest diagnostic effectiveness also in the overall (45.50% to 73.90%) and physical-related (45.50% to 69.90%) scales/items, but they did not discriminate exactly athletes in fatigued or recovered state compared to the performance criterion measures. Correlation analyses also revealed no significant relationships between the changes in the scales/items and in the criterion measures. On a descriptive basis, comparisons with the change effect sizes and the sensitivity results of the performance and physiological markers underline the importance of psychological markers for the assessment of recovery and stress. Furthermore, the gained experiences in application and evaluation promote the practicability and economy of the questionnaires favouring the combination of subjective and objective markers for training monitoring in sports. The application and interpretation should mainly focus on the individual and longitudinal level.

Physical and Physiological Attributes of Wrestlers: An Update.

Chaabene, H, Negra, Y, Bouguezzi, R, Mkaouer, B, Franchini, E, Julio, U, and Hachana, Y. Physical and physiological profile of wrestler athletes: a short review. J Strength Cond Res 31(5): 1411-1442, 2017-Wrestling is one of the oldest combat sports, disputed since the ancient Greek Olympic Games. This combat sport discipline has caught the attention of scientists since 1943 which is the date that matches the appearance of the first scientific research dealing with wrestling. The current short review aimed to summarize and critically analyze the scientific literature related to wrestling's physical and physiological attributes and to provide practical recommendations for testing/training together with new perspective and areas of future scientific research. Regardless of sex and wrestling styles, an optimal level of cardiorespiratory fitness is important to help sustaining effort throughout the duration of the match and to stimulate the recovery process between periods. With regard to the anaerobic power and capacity, the available studies were in agreement about their critical importance toward reaching high-level wrestling success since these variables have discriminated well between successful and less-successful wrestlers regardless of age, weight classes, and wrestling styles. Physical fitness parameters such as maximal dynamic strength, isometric strength, explosive strength, and strength endurance are closely related to high-level wrestling performance. However, flexibility level seems not to be one of the key fitness variables that help to reach high-level wrestling success. Overall, to achieve high-level wrestling performance, training should be directed to develop anaerobic power and capacity, aerobic power, maximal dynamic and isometric strength, explosive strength, and strength endurance.

Effects Of High-intensity Functional Circuit Training On Motor Function And Exercise Motivation

PURPOSE: Only a small share of the world population meets current physical activity guidelines, which recommend regular engagement in endurance, strength, and neuromotor exercise. As lack of time has been reported to constitute a major cause of inactivity, multidimensional methods with short training duration might be a promising alternative to classical, volume-oriented approaches. This randomized-controlled trial aimed to examine the effects of a high-intensity functional circuit (HIFCT) training program on motor function and motivation to exercise in healthy, untrained adults. METHODS: 25 inactive participants (26±5 yrs, 9♂) were randomly allocated to two groups. The intervention group (HIFCT, n=15) 3×/wk performed functional exercises incorporating complex whole-body movements (e.g. Squats, Step-Ups, Burpees) in a circuit format. The 15 min workouts were composed of repetitive 20s all-out bouts with 10s breaks. In the comparison group (moderate aerobic exercise, MAE) the participants walked 3×/wk for 50 min at moderate intensity (progressively increased from 50 to 60% of the individual heart rate reserve). Motor outcomes, measured prior to and after the six-week intervention, were cycling capacity (maximum work load), dynamic maximum strength (leg and shoulder press), postural control (force plate), and jump capacity (reactive strength index, counter-movement jump, single leg hop for distance). Motivation to exercise was assessed using the self-concordance index. Systematic group differences were detected with the Mann-Whitney-U-test (α=.05). RESULTS: In comparison to MAE, HIFCT increased maximum leg strength (difference of relative median pre-post changes between groups: 6%), shoulder strength (8.4%), and cycling workload (6.5%; p<.05). No differences were found for postural control and jump capacity (p>.05). Although not statistically significant, there was a tendency for increased self-concordance following HIFCT (p<.1) CONCLUSION: Despite considerably shorter training duration, HIFCT enhances motor function in healthy untrained adults more effectively than MAE. It might moreover be better suited to motivate inactive people to engage in regular activity. Further research should thus investigate long-term adherence to the program and its effectivity in other settings.

Improvements in Chilean patients with obesity following a 5-month multidisciplinary exercise program: a feasibility study.

The aim of this study was to determine the effects of a multidisciplinary exercise program on physical fitness, metabolic profile and nutritional status of obese patients. Seventeen women and four men (N.=21, age 18 to 60 years), with severe obesity (BMI=35-40 kg/m2, N.=7), morbid obesity (BMI=40-50 kg/m2, N.=9), and super obesity (BMI>50 kg/m2, N.=5), took part in a physical exercise program with nutritional and psychological support. The intermittent physical exercise program was applied three times per week (1 hour/session), with 4-8 exercises with weights. Three series were carried out for 60 s each, with increasing intensity leading to exhaustion at the end of the period and with 1-2 min recovery between series. Outcomes include the BMI, waist contour, blood pressure, cardiorespiratory fitness, exercise capacity, maximum dynamic strength, hand grip strength, basal glucose and lipid profiles. The patients decreased in weight and BMI (P<0.05). Morbid (N.=9) and super obese (N.=5) improved their cardiorespiratory fitness (P=0.005 and 0.040) and lowered their triglycerides (-25.70% and -15.38%; P=0.008). Hand grip strength improved in the super obese (P<0.001). Descriptively, patients with super obesity had the largest improvements. Multi-modal lifestyle and exercise interventions improve the condition especially in super obese patients. The improved health status may improve the outcome of secondary steps in weight loss, such as bariatric surgery. The program was feasible to be executed and patients compliant to the intervention.

Predicting the Maximum Dynamic Strength in Bench Press: The High Precision of the Bar Velocity Approach.

Loturco, I, Kobal, R, Moraes, JE, Kitamura, K, Cal Abad, CC, Pereira, LA, and Nakamura, FY. Predicting the maximum dynamic strength in bench press: the high precision of the bar velocity approach. J Strength Cond Res 31(4): 1127-1131, 2017-The aim of this study was to determine the force-velocity relationship and test the possibility of determining the 1 repetition maximum (1RM) in "free weight" and Smith machine bench presses. Thirty-six male top-level athletes from 3 different sports were submitted to a standardized 1RM bench press assessment (free weight or Smith machine, in randomized order), following standard procedures encompassing lifts performed at 40-100% of 1RM. The mean propulsive velocity (MPV) was measured in all attempts. A linear regression was performed to establish the relationships between bar velocities and 1RM percentages. The actual and predicted 1RM for each exercise were compared using a paired t-test. Although the Smith machine 1RM was higher (10% difference) than the free weight 1RM, in both cases the actual and predicted values did not differ. In addition, the linear relationship between MPV and percentage of 1RM (coefficient of determination ≥95%) allow determination of training intensity based on the bar velocity. The linear relationships between the MPVs and the relative percentages of 1RM throughout the entire range of loads enable coaches to use the MPV to accurately monitor their athletes on a daily basis and accurately determine their actual 1RM without the need to perform standard maximum dynamic strength assessments.

Effects of adding a weekly eccentric-overload training session on strength and athletic performance in team-handball players

To investigate the influence of adding a weekly eccentric-overload training (EOT) session in several athletic performance’s tests, 18 team-handball players were assigned either to an EOT (n = 11) or a Control (n = 7) group. Both groups continued to perform the same habitual strength training, but the EOT group added one session/week during a 7-week training programme consisting of four sets of eight repetitions for the bilateral half-squat and unilateral lunge exercises. The test battery included handball throwing velocity, maximum dynamic strength (1RM), countermovement jump (CMJ), 20 m sprint, triple hop for distance, and eccentric/concentric power in both the half-squat and lunge exercises. Data were analysed using magnitude-based inferences. Both groups improved their 1RM in the half squat, 20 m sprint time, and CMJ performance to a similar extent, but the EOT group showed a beneficial effect for both right [(42/58/0), possibly positive] and left [(99/1/0), very likely positive] triple hop for distance performance. In addition, the EOT group showed greater power output improvements in both eccentric and concentric phases of the half-squat (difference in percent of change ranging from 6.5% to 22.0%) and lunge exercises (difference in per cent of change ranging from 13.1% to 24.9%). Nevertheless, no group showed changes in handball throwing velocity. Selected variables related to team-handball performance (i.e. functional jumping performance, power output) can be improved by adding a single EOT session per week, highlighting the usefulness of this low-volume/high-intensity training when aiming at optimizing dynamic athletic performance.

Maximal and submaximal oxygen uptake efficiency slope: influence of cardiorespiratory variables and maximal dynamic strength

Maximal and submaximal oxygen uptake efficiency slope: influence of cardiorespiratory variables and maximal dynamic strength

Maximum Strength Estimate of Quadriceps and Brachial Biceps Muscles in Patients with Chronic Heart Disease

Patients diagnosed with heart disease display diminished exercise tolerance, which can be attributed not only to a reduction in aerobic capacity but probably also to a strength deficit. The aim of this study was to estimate maximum dynamic strength of the quadriceps and the brachial biceps muscles in patients affected by chronic heart disease. Maximum strength was estimated by means of sub-maximal tests in 30 healthy sedentary volunteers and 140 male patients with chronic heart disease: 52 patients with coronary artery disease (CA D); 72 patients diagnosed with chronic heart failure (CHF); 16 patients who had undergone heart transplant (HT). Maximum strength estimate of the two muscles tested was significantly lower in patients diagnosed with heart disease compared to the control group. When patients were subdivided according to the type of disease, a clear trend among groups was displayed with maximum strength being higher in controls, followed by the CA D group, then the CHF group, and the HT group. In conclusion it seems possible to assert that maximum strength of both the muscle groups examined is significantly lower in patients diagnosed with cardiovascular disease than in control subjects. Moreover, chronic cardiovascular patients are characterized by a muscular impairment that parallels the history of the disease. This information should be kept in mind when planning a rehabilitation program.

Neuromuscular Adaptations to Same-Session Combined Endurance and Strength Training in Recreational Endurance Runners.

This study examined neuromuscular adaptations in recreational endurance runners during 24 weeks of same-session combined endurance and strength training (E+S, n=13) vs. endurance training only (E, n=14). Endurance training was similar in the 2 groups (4-6x/week). Additional maximal and explosive strength training was performed in E+S always after incremental endurance running sessions (35-45 min, 65-85% HRmax). Maximal dynamic leg press strength remained statistically unaltered in E+S but decreased in E at week 24 (-5±5%, p=0.014, btw-groups at week 12 and 24, p=0.014 and 0.011). Isometric leg press and unilateral knee extension force, EMG of knee extensors and voluntary activation remained statistically unaltered in E+S and E. The changes in muscle cross-sectional (CSA) differed between the 2 groups after 12 (E+S+6±8%, E -5±6%, p<0.001) and 24 (E+S+7±7%, E -6±5%, p<0.001) weeks. 1 000 m running time determined during an incremental field test decreased in E+S and E after 12 (-7±3%, p<0.001 and -8±5%, p=0.001) and 24 (-9±5%, p=0.001 and -13±5%, p<0.001) weeks. Strength training performed always after an endurance running session did not lead to increased maximal strength, CSA, EMG or voluntary activation. This possibly contributed to the finding of no endurance performance benefits in E+S compared to E.

Acute Effect of A Judo Contest on Muscular Performance Parameters And Physiological Response

Background: It is necessary to know accurately the physical effects of judo contest on athletes in order to quantify how successive judo bouts impair muscular performance parameters and physiological response associated with the aim to create specific training programs that take the demands of judo bout into account. Purpose : The purpose of current study was to characterise the evolution of muscular performance parameters and physiological response during a judo contest. Methods : Twenty-nine men performed five 5-minute bouts with 15 minutes of passive rest. Immediately after the bouts, some muscular performance parameters and physiological variables were measured, in this order: Borg´s rate of perceived exertion (RPE), maximal dynamic strength in upper body (MDS), countermovement jump (CMJ), dominant (DHS) and non-dominant handgrip isometric strength (NDHS). Lactate (LAC) was measured 3 minutes after each bout and 1 minute before the next too). Heart rate (HR) was monitored during the contest. ANOVA to compare baseline test data and successive bouts was used. Results : ANOVA revealed significant differences in HR mean (p=0.045), LAC (p<0.001) and in RPE (p<0.001). A decrease in NDHS (p<0.001), DHS (p<0.001), MDS (p<0.001) was found. Some significant correlations were found between NDHS and DMPV (r=0.368, p=0.050), DMS (r=0.369, p=0.050) and DMXS (r=0.405, p=0.029); between DHS and DLACb (r=0.430, p=0.020), DMXS (r=0.379, p=0.043), DMP (r=0.369, p=0.050) and DRPE (r=0.456, p=0.013); between CMJ and DPM (r=0.381, p=0.041), DPMX (r=0.417, p=0.024), DFM (r=0.423, p=0.022) and DDHS (r=0.348, p=0.040). These results show a high decrease of muscular performance parameters and an increase of physiological parameters, specially between baseline test and postbout 5, but gradual between all bouts. Conclusion : Judo contest can be considered a high intensity exercise, due to high levels of physiological parameters and the decrease in force production obtained. Keywords: judo contest, bouts, muscular performance parameters, physiological response, physiological parameters, fatigue

Effects of 4-Week Training Intervention with Unknown Loads on Power Output Performance and Throwing Velocity in Junior Team Handball Players.

PurposeTo compare the effect of 4-week unknown vs known loads strength training intervention on power output performance and throwing velocity in junior team handball players.MethodsTwenty-eight junior team-handball players (17.2 ± 0.6 years, 1.79 ± 0.07 m, 75.6 ± 9.4 kg)were divided into two groups (unknown loads: UL; known loads: KL). Both groups performed two sessions weekly consisting of four sets of six repetitions of the bench press throw exercise, using the 30%, 50% and 70% of subjects’ individual 1 repetition maximum (1RM). In each set, two repetitions with each load were performed, but the order of the loads was randomised. In the KL group, researchers told the subjects the load to mobilise prior each repetition, while in the UL group, researchers did not provide any information. Maximal dynamic strength (1RM bench press), power output (with 30, 50 and 70% of 1RM) and throwing velocity (7 m standing throw and 9 m jumping throw) were assessed pre- and post-training intervention.ResultsBoth UL and KL group improved similarly their 1RM bench press as well as mean and peak power with all loads. There were significant improvements in power developed in all the early time intervals measured (150 ms) with the three loads (30, 50, 70% 1RM) in the UL group, while KL only improved with 30% 1RM (all the time intervals) and with 70% 1RM (at certain time intervals). Only the UL group improved throwing velocity in both standing (4.7%) and jumping (5.3%) throw (p > 0.05).ConclusionsThe use of unknown loads has led to greater gains in power output in the early time intervals as well as to increases in throwing velocity compared with known loads. Therefore unknown loads are of significant practical use to increase both strength and in-field performance in a short period of training.

Effect Of Training Frequency On Muscle Mass, Strength And Power Performance During Reduced Resistance Training

Reduced resistance training (RRT) has been suggested to maintain muscular adaptations (e.g. muscle hypertrophy, muscle strength power). The RRT may be applied after a period of high intensity resistance training (HIRT) by reducing training volume and changing frequency. Several studies have shown positive RRT effects when training volume is decreased 50-60%. However, the effects of different training frequencies during RRT on muscle mass, muscle strength and power performance remain unknown. PURPOSE: To investigate the effect of different training frequencies on muscle mass, strength and power performance during a period of RRT. METHODS: Thirty three physically active male subjects were submitted to 8 weeks of upper limbs high intensity resistance training (HIRT) divided into two 4-wk periods (i.e. 2.d.wk−1 the first 4 wk and 3.d.wk−1 the last 4 wks). After that they randomly assigned to three experimental groups: reduced resistance training 2 (RRT2 = two sessions per week), reduced resistance training 1 (RRT1 = one session per week), and detraining (DT = interrupted training). RRT1 and RRT2 reduced training session volume by 50-55% and DT group detrained for 8 more weeks. Triceps brachii cross sectional area (TCSA), maximal dynamic strength (1RM), and muscle power (PPw) in the bench press exercise were measured before, after RT, and after RRT. RESULTS: RRT1, RRT2, and DT showed similar increases in the TCSA after the HIRT period [16.5% (±3.6), 15.9% (±2.7), and 17.1% (±4.6) (p<0.01), respectively]. The 1RM and PPw also increased similarly for all three groups [17.2% (±2.9), 41.1% (±6.4), and 41.8% (±5.1) and 15.8% (±6.4), 15.3% (±5.4), and 18.2% (±7.3), respectively]. After the RRT period, RRT1 and RRT2 groups were able to maintain their TCSA, 1RM and PPw performance while DT showed significant decreases in TCSA (13.1±4.2%), 1RM (23.7±6.8%), and PPw (15.7±5.3%). CONCLUSION: The results showed that RRT performed once or twice a week but with similar training volume is able to maintain muscle hypertrophy, strength and power performance obtained after 8 weeks of HIRT.

Effects of Periodized Strength Training Regimens on Functional and Morphological Adaptations of Skeletal Muscle

It has been suggested that periodized strength training (ST) regimens optimize the training-induced adaptations. PURPOSE: The purpose of current study was to investigate the effects of different periodized and non-periodized regimens on functional performance and morphological skeletal muscle adaptations. METHODS: Thirty-four participants (age=24.6 ±5.4 years) were random allocated into four groups: control (C), non-periodized (NP), traditional periodized (TP) and daily undulating periodized (UP). Experimental groups underwent 12 weeks of ST twice a week, and performed half-squat and knee extensors exercises (i.e. 2-4 sets, 4-12 repetitions). Maximum dynamic strength (1RM) and quadriceps cross-sectional area (CSA) were evaluated at baseline and after six and 12 weeks of training. RESULTS: Training groups had similar total volume load over the experimental period (NP 92.598 ± 15.340kg; TP: 92.973kg ± 10.760kg; UP 108.367 ± 18.316kg [p>0.05]). Only NP and UP increased 1RM after six weeks (17.0 ± 8.7%, p<0.0001; 12.9 ± 9.9%, p<0.01, respectively). After 12 weeks, NP, TP and UP increased 1RM values (19.5 ± 13.2%; p<0.0001; 17.9 ± 13.7%; p<0.0001; 20.4 ± 9.0%; p<0.0001 respectively). All experimental groups increased quadriceps CSA after six (5.1 ± 2.7%, p < 0.0001) and 12 weeks (9.5 ± 4.5% p < 0.0001) of training. Furthermore, only GPL significantly increased quadriceps CSA between six and 12 weeks (6.4%, p<0.0001). CONCLUSION: Even though experimental groups presented differences in the time-course of functional performance and morphological adaptations, overall between-group effects suggest similar efficiency of the training regimens for healthy male individuals.

Effect of traditional resistance and power training using rated perceived exertion for enhancement of muscle strength, power, and functional performance.

The present study compared the effects of 12weeks of traditional resistance training and power training using rated perceived exertion (RPE) to determine training intensity on improvements in strength, muscle power, and ability to perform functional task in older women. Thirty healthy elderly women (60-75years) were randomly assigned to traditional resistance training group (TRT; n=15) or power training group (PT; n=15). Participants trained twice a week for 12weeks using six exercises. The training protocol was designed to ascertain that participants exercised at an RPE of 13-18 (on a 6-20 scale). Maximal dynamic strength, muscle power, and functional performance of lower limb muscles were assessed. Maximal dynamic strength muscle strength leg press (≈58%) and knee extension (≈20%) increased significantly (p<0.001) and similarly in both groups after training. Muscle power also increased with training (≈27%; p<0.05), with no difference between groups. Both groups also improved their functional performance after training period (≈13%; p<0.001), with no difference between groups. The present study showed that TRT and PT using RPE scale to control intensity were significantly and similarly effective in improving maximal strength, muscle power, and functional performance of lower limbs in elderly women.

Strength and Power Training Effects on Lower Limb Force, Functional Capacity, and Static and Dynamic Balance in Older Female Adults

It has been proposed that muscle power is more effective to prevent falls than muscle force production capacity, as rapid reactions are required to allow the postural control. This study aimed to compare the effects of strength and power training on lower limb force, functional capacity, and static and dynamic balance in older female adults. Thirty-seven volunteered healthy women had been allocated into the strength-training group (n = 14; 69 ± 7.3 years, 155 ± 5.6 cm, 72 ± 9.7 kg), the power-training group (n = 12; 67 ± 7.4 years, 153 ± 5.5 cm, 67.2 ± 7 kg), and control group (n = 11; 65 ± 3.1 years, 154 ± 5.6 cm, 70.9 ± 3 kg). After 12 weeks of training, the strength-training and power-training groups increased significantly maximum dynamic strength (29% and 27%), isometric strength (26% and 37%), and step total time (13% and 14%, dynamic balance), respectively. However, only the power-training group increased the rate of torque development (55%) and the functional capacity in 30-second chair stand (22%) and in time up and go tests (-10%). Empirically, power training may reduce the risk of injuries due to lower loads compared to strength training, and consequently, the physical effort demand during the training session is lower. Therefore, power training should be recommended as attractive training stimuli to improve lower limb force, functional capacity, and postural control of older female adults.

Theoretical interpretation of abnormal ultrafine-grained material deformation dynamics

Some recent experiments with ultrafine-grained metal samples reveal that it has an abnormal mechanical response on the intensive dynamical loading caused by its impact or electron beam irradiations. On the basis of the original plasticity model, which takes into account dislocation slip and grain boundary sliding, we show that this response is usual for such structure. Moreover, our calculations predict an inverse Hall–Petch relation for ultrafine grained metals at extremely high strain rates (above 107 s−1), while the classical low strain rate experiments and molecular dynamic simulations detects such inverse Hall–Petch relation only for nanocrystalline materials. The main outcomes of present work are the described plasticity model and the conclusions that the ultrafine-grained metals (with grains of about 100–200 nm in diameter) has to have maximal dynamic shear strength and it is the most persistent to dynamic spall fracture because of maximal energy dissipation in it.

Effects of Whole‐Body Electromyostimulation versus High‐Intensity Resistance Exercise on Body Composition and Strength: A Randomized Controlled Study

High-intensity (resistance) exercise (HIT) and whole-body electromyostimulation (WB-EMS) are both approaches to realize time-efficient favorable changes of body composition and strength. The purpose of this study was to determine the effectiveness of WB-EMS compared with the gold standard reference HIT, for improving body composition and muscle strength in middle-aged men. Forty-eight healthy untrained men, 30–50 years old, were randomly allocated to either HIT (2 sessions/week) or a WB-EMS group (3 sessions/2 weeks) that exercised for 16 weeks. HIT was applied as “single-set-to-failure protocol,” while WB-EMS was conducted with intermittent stimulation (6 s WB-EMS, 4 s rest; 85 Hz, 350 ms) over 20 minutes. The main outcome parameters were lean body mass (LBM) as determined via dual-energy X-ray absorptiometry and maximum dynamic leg-extensor strength (isokinetic leg-press). LBM changes of both groups (HIT 1.25 ± 1.44% versus WB-EMS 0.93 ± 1.15%) were significant (p = .001); however, no significant group differences were detected (p = .395). Leg-extensor strength also increased in both groups (HIT 12.7 ± 14.7%, p = .002, versus WB-EMS 7.3 ± 10.3%, p = .012) with no significant (p = .215) between-group difference. Corresponding changes were also determined for body fat and back-extensor strength. Conclusion. In summary, WB-EMS can be considered as a time-efficient but pricy option to HIT-resistance exercise for people aiming at the improvement of general strength and body composition.

The effects of water-based exercise in combination with blood flow restriction on strength and functional capacity in post-menopausal women.

Water-based exercise and low-intensity exercise in combination with blood flow restriction (BFR) are two methods that have independently been shown to improve muscle strength in those of advancing age. The objective of this study was to assess the long-term effect of water-based exercise in combination with BFR on maximum dynamic strength and functional capacity in post-menopausal women. Twenty-eight women underwent an 8-week water-based exercise program. The participants were randomly allocated to one of the three groups: (a) water exercise only, (b) water exercise + BFR, or (c) a non-exercise control group. Functional capacity (chair stand test, timed up and go test, gait speed, and dynamic balance) and strength testing were tested before and after the 8-week aquatic exercise program. The main findings were as follows: (1) water-based exercise in combination with BFR significantly increased the lower limb maximum strength which was not observed with water-based exercise alone and (2) water-based exercise, regardless of the application of BFR, increased functional performance measured by the timed up and go test over a control group. Although we used a healthy population in the current study, these findings may have important implications for those who may be contraindicated to using traditional resistance exercise. Future research should explore this promising modality in these clinical populations.

Using Bar Velocity to Predict the Maximum Dynamic Strength in the Half-Squat Exercise.

To determine whether athletes from different sport disciplines present similar mean propulsive velocity (MPV) in the half-squat (HS) during submaximal and maximal tests, enabling prediction of 1-repetition maximum (1-RM) from MPV at any given submaximal load. Sixty-four male athletes, comprising American football, rugby, and soccer players; sprinters and jumpers; and combat-sport strikers attended 2 testing sessions separated by 2-4 wk. On the first visit, a standardized 1-RM test was performed. On the second, athletes performed HSs on Smith-machine equipment, using relative percentages of 1-RM to determine the respective MPV of submaximal and maximal loads. Linear regression established the relationship between MPV and percentage of 1-RM. A very strong linear relationship (R2 ≈ .96) was observed between the MPV and the percentages of HS 1-RM, resulting in the following equation: %HS 1-RM = -105.05 × MPV + 131.75. The MPV at HS 1-RM was ~0.3 m/s. This equation can be used to predict HS 1-RM on a Smith machine with a high degree of accuracy.

Training for Power and Speed: Effects of Increasing or Decreasing Jump Squat Velocity in Elite Young Soccer Players.

The aim of this study was to test the effects of 2 different velocity-oriented power training regimens by either increasing or decreasing the jump squat velocity during jump training sessions applied 3 times a week for 6 weeks in soccer players. Twenty-four elite under-20 soccer players were randomly assigned to an increased bar velocity group (IVG) or a reduced bar velocity group (RVG). Athletes had their countermovement jump heights, mean propulsive velocities (MPVs) in jump squat, leg press maximum dynamic strength (1 repetition maximum [RM]), 20-m sprint times, and zig-zag change of direction (COD) abilities assessed before and after the intervention. Performance in all tests improved after training in both groups. However, greater gains in 1RM and MPV using 50-90% of body mass (BM) were noted for the RVG. The IVG demonstrated greater improvements in speed at 5, 10, and 20 m and MPV with no additional external load and with 40% BM. Both groups improved similarly in countermovement jumps and COD. To conclude, both velocity-oriented power training regimens were effective in eliciting neuromechanical adaptations, leading to better strength/power/speed performances, and the choice as to the most suitable method should be tailored according to players' needs/deficiencies.