Horizontal Leg Press Research Articles

Acute cardiovascular responses of postmenopausal women to resistance training sessions differing in set configuration: A study protocol for a crossover trial.

Resistance training is hardly recommended for postmenopausal women to counteract negative effects of hormonal changes. However, some concern exists about the marked hemodynamic responses caused by high-load resistance exercises. In this regard, studies on young, healthy, physically active individuals suggest that set configuration can modulate acute cardiovascular, metabolic, and cardiac autonomic responses caused by resistance training sessions, but this has not yet been explored in postmenopausal women. A sample of 60 physically active postmenopausal women (30 normotensive, 30 hypertensive) will participate in this crossover study. After a medical exam, ergometry, familiarization session, and two testing sessions, participants will complete three experimental sessions and one control session in a randomized order. Each experimental session includes 36 repetitions of four exercises (horizontal leg press, bench press, prone leg curl, and lat pull-down) differing in set configuration: 9 sets of 4 repetitions (i.e., 33% intensity of effort) with 45 s of inter-set recovery, 6 sets of 6 repetitions (50% intensity of effort) with 72 s, and 4 sets of 9 repetitions (75% intensity of effort) with 120 s; with 4 min rest between exercises. Before and immediately after each session, arterial stiffness, hemodynamic variables, cardiac autonomic modulation, baroreflex sensitivity, sympathetic vasomotor tone, and resting oxygen uptake will be evaluated. Furthermore, perceived effort, mechanical performance (e.g., power, velocity), heart rate, and lactatemia will be collected throughout sessions. The impact of set configuration on these variables will be analyzed, along with comparisons between normotensive and hypertensive women. Cardiovascular responses to resistance exercise have been scarcely studied in females, particularly postmenopausal women. The results of this study will provide information about the modulating role of set structure on metabolic and cardiovascular responses of normotensive and hypertensive postmenopausal women to resistance training. NCT05544357 on 7 December 2022.

Variability in the Relationship Between Velocity Loss and Percentage of Completed Repetitions During Horizontal Leg Press and Bench Press in Postmenopausal Women.

Iglesias-Soler, E, Rial-Vázquez, J, Nine, I, Fariñas, J, Revuelta-Lera, B, and García-Ramos, A. Variability in the relationship between velocity loss and percentage of completed repetitions during horizontal leg press and bench press in postmenopausal women. J Strength Cond Res 38(9): 1576-1583, 2024-This study aimed to analyze the intersubject variability in the relationship between percentage of velocity loss (%VL) and percentage of repetitions performed out of maximum possible (%MNR) in postmenopausal women. Thirty-five postmenopausal active women (58 ± 3 years) performed sets leading to muscular failure, completing 10-13 repetitions, in both leg press (LP) and bench press (BP). Mean lift velocity of each repetition was expressed as a percentage of the fastest repetition, and repetitions were quantified as a percentage of the maximum number of repetitions completed in the set. Given the hierarchical structure of the data, %VL-%MNR relationships were fitted by linear mixed model regressions. A significant intersubject variability in the intercept (i.e., %MNR associated with 0%VL) was detected ( p < 0.001 in both LP and BP), even when centered values of the completed repetitions were included in the models. The estimated variance in the intercept for LP (117.39; SE : 45.41) was almost double that for BP (67.47; SE : 20.27). The variability observed in the intercept entailed variability in the estimated %MNR for specific %VL values. The use of velocity loss thresholds for estimating the intensity of effort in active postmenopausal women does not overcome uncertainty of more traditional methods.

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.

Upright versus Horizontal Squat Jumps: A comparison of peak force, peak velocity, peak power and muscle activity in male athletes

Sports performance coaches and rehabilitation specialists commonly prescribe explosive squat jumps (SJ) in the upright position to improve lower body power using loads based upon an individual’s one-repetition maximum (1RM) back squat. Recently, using a horizontal leg press to perform SJ has become popular purportedly due to its less technical nature. To date, little research exists comparing upright and horizontal SJ. Therefore, this investigation examined peak force, peak velocity, peak power and muscle activity of upright versus horizontal SJ using loads based upon each condition’s respective 1RM. Twelve males completed two sets of three repetitions of SJ at 20%, 30%, 40%, 50% and 60%1RM. Statistical significance was set to P ≤ 0.05. No significant differences existed between trial 1 and 2 for any measures. Two-way analysis of variance revealed a) no significant difference in peak force between the SJ conditions at any intensity; b) significantly greater peak velocity during upright SJ at all intensities; c); significantly greater peak power during upright SJ at all intensities; and d) no difference in muscle activity between SJ conditions. In conclusion, in a key measure of performance, power output during upright SJ was significantly greater than during horizontal SJ.

Programações linear e ondulatória do treinamento de força induzem a mesmos resultados na aptidão física em mulheres idosas

Abstract The aim of the present study was to analyze the effect of two different types of resistance training programming (linear and daily undulating) on submaximal strength and functional capacity in elderly women. Twenty-two participants (64 ± 3 years) were randomly assigned to 2 training groups: linear programming (LP; n=12) and daily undulating programming (DUP; n =10). Functional capacity and submaximal strength (10RM) were analyzed before and after 12 weeks of resistance training. The results demonstrated improvement on strength and functional capacity after the resistance training period (p ≤ 0.05), except for the Bench Press (p = 0.30), for both groups DUP and LP. The Effect Size was, respectively, high for DUP (timed up and go test = -2.07, and timed sit test= 4.69), and high for LP (horizontal leg press = 2.35). For all other results, the effect size was trivial or small. No statistical difference was observed between programming models. The LP and DUP trainnings have similar results in increasing submaximal muscle strength in elderly women inexperienced in RT after 12 weeks of intervention (p ≤ 0,05). However, DUP appears to be more effective in increasing functional capacity. In practice, the professional can use both the LP and the DUP to improve the level of fitness in the early stages of training in this population. However, when the goal of programming is to increase functional capacity, DUP can be prioritized.

Retrograde Training: Effects on Lower Body Strength and Power.

Backward walking and running on positive grades (retrograde training) represents a closed kinetic chain exercise used by rehabilitation specialists for patellofemoral-related injuries. To date, no longitudinal studies exist to support it use. This investigation examined the effects of retrograde training on lower body strength and power in recreational athletes aged 18-50 years over 6 weeks. Thirty-seven subjects were divided into two groups. Group 1 performed retrograde training 3 days∙wk-1 using treadmill speeds, grades and bout durations ranging from 1.6-4.9 m∙sec-1, 2.5-27.5% and 10-30 seconds, respectively (RG, n=19). Group 2 was a control group who continued their normal training (CON, n=18). Pre- and posttests assessed a variety of unilateral and bilateral measures including vertical and linear jumps, one repetition maximum leg press strength, and positive and negative power during weighted squat jumping on a horizontal leg press with a force plate. RG improved significantly in all tests (P<0.05). Mean effect size (ES) of the relative improvement in a majority of tests revealed a moderate to very large ES of RG training (ES range: 0.77-2.71). We conclude retrograde training effective for improving lower body strength and power in recreational athletes.

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

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

Comparison of Joint and Muscle Biomechanics in Maximal Flywheel Squat and Leg Press.

The aim was to compare the musculoskeletal load distribution and muscle activity in two types of maximal flywheel leg-extension resistance exercises: horizontal leg press, during which the entire load is external, and squat, during which part of the load comprises the body weight. Nine healthy adult habitually strength-training individuals were investigated. Motion analysis and inverse dynamics-based musculoskeletal modelling were used to compute joint loads, muscle forces, and muscle activities. Total exercise load (resultant ground reaction force; rGRF) and the knee-extension net joint moment (NJM) were slightly and considerably greater, respectively, in squat than in leg press (p ≤ 0.04), whereas the hip-extension NJM was moderately greater in leg press than in squat (p = 0.03). Leg press was performed at 11° deeper knee-flexion angle than squat (p = 0.01). Quadriceps muscle activity was similar in squat and leg press. Both exercise modalities showed slightly to moderately greater force in the vastii muscles during the eccentric than concentric phase of a repetition (p ≤ 0.05), indicating eccentric overload. That the quadriceps muscle activity was similar in squat and leg press, while rGRF and NJM about the knee were greater in squat than leg press, may, together with the finding of a propensity to perform leg press at deeper knee angle than squat, suggest that leg press is the preferable leg-extension resistance exercise, both from a training efficacy and injury risk perspective.

Load-velocity relationship in the horizontal leg-press exercise in older women and men.

This study analyzed the predictive ability of movement velocity to estimate the relative load (i.e., % of one-repetition maximum [1RM]) during the horizontal leg-press exercise in older women and men. Twenty-four women and fourteen men living in community-dwelling centers volunteered to participate in this study. All participants performed a progressive loading test up to 1RM in the horizontal leg-press. The fastest peak velocity (PV) and mean velocity (MV) attained with each weight were collected for analysis. Linear regression equations were modeled for women and men. We observed very strong linear relationships between both velocity variables and the relative load in the horizontal leg-press in women (PV: r2=0.93 and standard error of the estimate (SEE)=5.96% 1RM; MV: r2=0.94 and SEE=5.59% 1RM) and men (PV: r2=0.93 and SEE=5.96% 1RM; MV: r2=0.94 and SEE=5.97% 1RM). The actual 1RM and the estimated 1RM using both the PV and MV presented trivial differences and very strong relationships (r=0.98-0.99) in both sexes. Men presented significantly higher (p<0.001-0.05) estimated PV and MV against all relative loads compared to women (average PV=0.81 vs. 0.69m·s-1 and average MV=0.44 vs. 0.38m·s-1). Our data suggest that movement velocity accurately estimates the relative load during the horizontal leg-press in older women and men. Coaches and researchers can use the proposed sex-specific regression equations in the horizontal leg-press to implement velocity-monitored resistance training with older adults.

Mechanical Characteristics of Heavy vs. Light Load Ballistic Resistance Training in Older Adults.

Rodriguez-Lopez, C, Alcazar, J, Sánchez-Martín, C, Ara, I, Csapo, R, and Alegre, LM. Mechanical characteristics in heavy vs. light load ballistic resistance training in older adults. J Strength Cond Res 36(8): 2094-2101, 2022-Although power-oriented resistance training (RT) is strongly recommended to counter age-related neuromuscular function declines, there is still controversy about which intensities of load should be used to elicit optimal training adaptations. Knowledge of the mechanical characteristics of power-oriented RT performed at different intensities might help to better understand the training stimulus that triggers load-dependent adaptations in older adults. Using a cross-over design, 15 well-functioning older volunteers (9 men and 6 women; 73.6 ± 3.8 years) completed 2 volume × load-matched ballistic RT sessions with heavy (HL: 6 × 6 × 80% 1-repetition maximum [1RM]) and light-load (LL: 6 × 12 × 40% 1RM) on a horizontal leg press exercise. Electromyographic (EMG) and mechanical variables (work, force, velocity, and power) as well as intraset neuromuscular fatigue (i.e., relative losses in force, velocity, and power) were analyzed. More concentric mechanical work was performed in the LL training session, compared with HL (36.2 ± 11.2%; p < 0.001). Despite the higher mean EMG activity of the quadriceps femoris muscle (13.2 ± 21.1%; p = 0.038) and greater concentric force (35.2 ± 7.6%; p < 0.001) during HL, higher concentric velocity (41.0 ± 12.7%, p < 0.001) and a trend toward higher concentric power (7.2 ± 18.9%, p = 0.075) were found for LL. Relative velocity losses were similar in both sessions (≈10%); however, relative force losses were only found in LL (7.4 ± 6.5%, p = 0.003). Considering the greater mechanical work performed and concentric power generated, ballistic RT using LL may, therefore, represent a stronger stimulus driving training adaptations as compared with volume × load-matched heavy-load training. Relative losses in force and power should be monitored in addition to velocity losses during ballistic RT.

CONCURRENT VALIDITY OF INSTRUMENTS FOR MEASURING SPEED OF MOVEMENT IN LEG PRESS EXERCISES

ABSTRACT Introduction Adequate measurement of movement velocity in strength exercises can assist in the prescription and evaluation of training effects. Objective The objectives of the present study were to analyze the reliability (test-retest) and concurrent validity of the movement velocity measured by means of the electrogoniometer and accelerometer during horizontal leg press exercise at different intensities (40, 60, 80% of a maximum repetition - 1RM). Methods Eighteen young women attended the laboratory on five occasions. After determining the maximum dynamic force, two visits (separated by 48-72 hours) were used to verify the reliability (test-retest) for different speed variables in the three intensities. Results The mean propulsive velocity obtained by the goniometer showed higher Intraclass correlation coefficients (ICC) and lower coefficients of variation compared to the accelerometer. The same behavior was observed for both the mean velocity and the peak velocity. The propulsive time was more reproducible and with less variation for the accelerometer and bad CCI for both sensors were observed at 60% of 1RM. When the sensors are compared, the mean and average propulsive velocities presented moderate ratios with a large to very large standardized medium bias. Conclusion The potentiometer of the electrogoniometer can be used to estimate the velocity in the horizontal leg press exercise, especially for loads of 60 and 80%. The performance of the accelerometer was inferior to that of the potentiometer. Level of evidence II; Diagnostic studies.

Cardiac Rehabilitation Combined Training Improves Lower Limb Strength After 12 Sessions In Elderly Patients

Increased quadriceps muscle strength has shown to decrease the risk of cardiovascular mortality by 34% in patients with coronary heart disease. Muscle mass and strength declines progressively in the elderly and training effects have been generally reported after 12 weeks. Adherence to cardiac rehabilitation programs is usually low, with less than 50% of patients completing 36 sessions in 12 weeks. There is still no consistent evidence that muscle strength in elderly patients can be improved after just 12 sessions of cardiac rehabilitation. PURPOSE: To evaluate the effect of 12 sessions of combined training on lower limb strength, in elderly patients attending a cardiac rehabilitation program 2-3 times per week. METHODS: Patients included eighty-four elderly (>60 yrs) (21 women, age 67 ± 6 yrs; 63 male, age 70 ± 7 yrs) attending a cardiac rehabilitation program in a university hospital in Bogotá city, Colombia. They were evaluated from January to September 2019 before and after 12 training sessions 2-3 times per week, which included 30 minutes of cardiovascular aerobic and 15 minutes of multifunctional strength training. Aerobic training was performed at 60 - 85% of the estimated maximal heart rate. Progressive resistance strength training included 3 sets of 10-15 repetitions of major muscle groups with 50 - 70% estimated 1-repetition maximum (1-RM) including elastic bands, cuff weights, free weights and gym machines. Baseline and follow up evaluation at the 12th session were performed by a horizontal leg press machine with 1-RM estimation according to Brzycki formula: (1-RM: 100* load repetition / (102.78 - 2.78 *rep). Pre/post training changes were assessed by paired t tests. RESULTS: After 12 training sessions a significant maximum strength increase was found, both for men (189.6 ± 42.6 vs 203.0 ± 47.4; p = 0.000), and women (116.1 ± 18.8 vs 140.6 ± 31.0; p = 0.000). CONCLUSIONS: This study showed that twelve sessions of combined training in elderly patients attending a cardiac rehabilitation program, improved lower limb strength in less time than usually reported. This finding supports the importance and feasibility of including strength in addition to aerobic training to reduce cardiovascular risk in this growing population.

Influence of gravity on biomechanics in flywheel squat and leg press

ABSTRACT Resistance exercise on Earth commonly involves both body weight and external load. When developing exercise routines and devices for use in space, the absence of body weight is not always adequately considered. This study compared musculoskeletal load distribution during two flywheel resistance knee-extension exercises, performed in the direction of (vertical squat; S) or perpendicular to (horizontal leg press; LP) the gravity vector. Eleven participants performed these two exercises at a given submaximal load. Motion analysis and musculoskeletal modelling were used to compute joint loads and to simulate a weightless situation. The flywheel load was more than twice as high in LP as in S (p < 0.001). Joint moments and forces were greater during LP than during S in the ankle, hip and lower back (p < 0.01) but were similar in the knee. In the simulated weightless situation, hip and lower-back loadings in S were higher than corresponding values at Earth gravity (p ≤ 0.01), whereas LP joint loads did not increase. The results suggest that LP is a better terrestrial analogue than S for knee-extension exercise in weightlessness and that the magnitude and direction of gravity during resistance exercise should be considered when designing and evaluating countermeasure exercise routines and devices for space.

INDICATORS OF NEUROMUSCULAR FATIGUE IN LEG PRESS EXERCISE IN MEN AND WOMEN

ABSTRACT Introduction Muscle fatigue is characterized by reduced ability to produce maximum strength or power, and may differ between men and women. Changes in velocity of movement during exercise, and in the ability to produce strength after exercise, may help when comparing fatigue in men and women. Objective To analyze the differences between men and women in relation to number of repetitions, kinetics, kinematics and isometric force-time curve performance, and their respective muscle activation in horizontal leg press exercises. Methods Fifteen men and fifteen women underwent isometric force-time curve (Cf-t) and electromyographic (EMG) assessments before and after performing horizontal leg press exercises. The exercises were performed in three sets until voluntary exhaustion, at 70% maximal repetition. During the exercises, kinetic and kinematic variables were obtained by means of two force transducers, a linear position potentiometer and accelerometer adapted for the horizontal leg press and synchronized by a signal conditioning plate. Results The mean propulsive velocity significantly reduced between the first and last repetition of each series, with a similar reduction for men (-12.4 to -29.2%) and women (-29.2 to -35.6%). The same pattern was observed for the other kinetic and kinematic variables. The maximum voluntary contraction and peak force development rate also decreased for both men (-15.1 ± 8.7% and -26.9 ± 21.2%, respectively) and women (-13.9 ± 10.4% and -28.2 ± 11.5%, respectively). Conclusion Based on the different variables used to quantify the effect of fatigue during and after horizontal leg press exercises, the research found practically no differences between men and women. Level of evidence II; Comparative prospective study.

Comparing the effects of resistance exercise type on serum levels of oxidative stress and muscle damage markers in resistance-trained women

The aim of the current study is to compare the effects of hypertrophy-, strength-, and power-type resistance exercise training types on hydrogen peroxide (H2O2), malondialdehyde (MDA), total lactate dehydrogenase (LDH), and total creatine kinase (CK) in resistance-trained women. After determining one-repetition maximum (1-RM), ten resistance-trained women (age 26.30 ± 4.95 years; body mass index 22.07 ± 2.02 kg/m2; body fat 24.64 ± 4.98%) conducted hypertrophy-type (70% of 1-RM), strength-type (90% of 1-RM), and power-type (45% of 1-RM) resistance exercise for three consecutive weeks. The movements included lever leg extension, reverse-grip lat pull-down, horizontal leg press, standing biceps cable curl, lying leg curl, machine bench press, standing cable triceps extension, and seated calf raises. Fasting blood samples were obtained immediately before and immediately after each trial. Statistical analyses were performed using the t test, Wilcoxon, and analysis of covariance. The significance level was set at P < 0.05 level. The results indicated that one bout of hypertrophy-, strength-, and power-type resistance exercises had no significant effects on H2O2, MDA, and total LDH levels. However, serum total CK level significantly increased after all the three types of resistance exercise. Power resistance exercise resulted in a higher total CK level than hypertrophy and strength types. Although the three types of hypertrophy, strength, and power exercise cause muscle damage, they do not exacerbate oxidative stress in resistance-trained women.

Assessing the Reliability of Using a Horizontal Leg Press Equipped With a Force Plate to Report on Measures of Positive and Negative Neuromuscular Characteristics.

Ferley, DD and Vukovich, MD. Assessing the reliability of using a horizontal leg press equipped with a force plate to report on measures of positive and negative neuromuscular characteristics. J Strength Cond Res 33(2): 360-371, 2019-Individuals participating in sport or returning from a lower-extremity injury routinely perform assessments of lower-body anaerobic capacity and power to gauge fitness or readiness to return to competition. However, many commonly used assessments lack the specificity of movement and muscle contraction demonstrated in sprinting, jumping, and changing direction. Therefore, this investigation assessed the reliability of a novel lower-body power test called a Plyo Press Power Quotient (3PQ), which involves jumping on a horizontal leg press equipped with a force plate. Thirty participants completed 1 repetition maximum (1RM) strength testing for 1 and 2 legs and a countermovement vertical jump. Two trials of 1- and 2-leg jump tests were performed using 30, 40, 50, and 60% of 1RM for 20 and 30 seconds, respectively. Dependent variables were a variety of positive (concentric) and negative (eccentric) neuromuscular indices. Statistical significance was set to p ≤ 0.05. No significant differences existed between trial 1 and 2 for any measures. One-way analysis of variance between %1RM conditions revealed significant differences in peak force (right; both), average negative power (left; right), average negative work (left; right), rate of power development (both), percent positive and negative fatigue (left; right; both), and velocity of movement (left; right; both). Peak power of all 2-leg jump tests correlated highly with vertical jump (r ≥ 0.89) but was significantly different. We conclude 3PQ testing provides a reliable assessment of anaerobic capacity and power, with the added benefit of easy single-leg comparisons.

Dominant and nondominant leg press training induce similar contralateral and ipsilateral limb training adaptations with children.

Cross-education has been extensively investigated with adults. Adult studies report asymmetrical cross-education adaptations predominately after dominant limb training. The objective of the study was to examine unilateral leg press (LP) training of the dominant or nondominant leg on contralateral and ipsilateral strength and balance measures. Forty-two youth (10-13 years) were placed (random allocation) into a dominant (n = 15) or nondominant (n = 14) leg press training group or nontraining control (n = 13). Experimental groups trained 3 times per week for 8 weeks and were tested pre-/post-training for ipsilateral and contralateral 1-repetition maximum (RM) horizontal LP, maximum voluntary isometric contraction (MVIC) of knee extensors (KE) and flexors (KF), countermovement jump (CMJ), triple hop test (THT), MVIC strength of elbow flexors (EF) and handgrip, as well as the stork and Y balance tests. Both dominant and nondominant LP training significantly (p < 0.05) increased both ipsilateral and contralateral lower body strength (LP 1RM (dominant: 59.6%-81.8%; nondominant: 59.5%-96.3%), KE MVIC (dominant: 12.4%-18.3%; nondominant: 8.6%-18.6%), KF MVIC (dominant: 7.9%-22.3%; nondominant: nonsignificant-3.8%), and power (CMJ: dominant: 11.1%-18.1%; nondominant: 7.7%-16.6%)). The exception was that nondominant LP training demonstrated a nonsignificant change with the contralateral KF MVIC. Other significant improvements were with nondominant LP training on ipsilateral EF 1RM (6.2%) and THT (9.6%). There were no significant changes with EF and handgrip MVIC. The contralateral leg stork balance test was impaired following dominant LP training. KF MVIC exhibited the only significant relative post-training to pretraining (post-test/pre-test) ratio differences between dominant versus nondominant LP cross-education training effects. In conclusion, children exhibit symmetrical cross-education or global training adaptations with unilateral training of dominant or nondominant upper leg.

Effect of a 16-month exercise training program on functional capacities in a centenarian male master athlete: A case study

The effects of exercise training have never been investigated in centenarians. This single-subject research study aimed to assess the effects of a structured training protocol on functional capacities in a centenarian master athlete. A 99.5 years old male subject participated in the study. Before and after a 16-month training intervention the participant underwent a test battery for flexibility (YMCA sit and reach), balance (single leg stance), upper limb strength (hand grip and pinch strength), and lower limb power (counter movement jump) and muscular endurance (horizontal leg press with 85 kg load). After training, sit and reach (-3 cm) and counter movement jump (- 0.5 cm) scores decreased, whereas single leg stance (+1.3 s), left hand grip (+2.0 kg), right hand pinch (+ 0.5 kg), and horizontal leg press (+2 repetitions) scores increased. Right hand grip strength and left-hand pinch strength did not change after training. When pre- and post-training scores were compared to gender-matched normative values, flexibility resulted well below average, maybe because of a relatively broad age category (> 65 years). When more specific age categories were available, the participant’s balance resulted slightly below average (age category 80-99 years) and upper limb strength above average (age category > 85 years). No normative values were found for lower limb power and muscular endurance. In conclusion, this study highlights that structured exercise training may play a role in maintaining – and even in increasing – functional capacities in the oldest old age.

Cardiac autonomic responses and number of repetitions maximum after LED irradiation in the ipsilateral and contralateral lower limb.

The aim of this study was to verify the maximum number of repetitions, fatigue index, blood lactate concentration ([Lac]), and cardiac autonomic responses after LED irradiation (LEDI) in the ipsilateral and contralateral limb. Twelve male subjects (22.0 ± 3.86years; weight 82.94 ± 12.58kg; height 1.77 ± 0.05m), physically active, took part in this study. The subjects underwent a one repetition maximum (1RM) test and performed four randomly experimental sessions in the horizontal leg press exercise, which consisted in four sets of maximum repetitions at 80% of 1RM. The subjects performed two experimental sessions applying LED active or placebo on ipsilateral limb and two experimental sessions applying LED active or placebo on contralateral limb prior exercise and in the interval of sets on quadriceps and hamstrings muscles. A number of repetitions and fatigue index were verified. [Lac] and heart rate variability (HRV) were collected during post-exercise recovery and analyzed. It was observed that active LEDI promoted an increase in maximal number of repetitions (LEDI = 44.4 ± 9.0 vs placebo = 39.9 ± 11.4; p < 0.05) and decreases the fatigue index (LEDI = 34.3 ± 21.8% vs placebo = 50.0 ± 26.6%; p < 0.05) comparing to placebo situation, only in the ipsilateral application. There were no differences on [Lac] and in HRV parameters comparing LEDI vs placebo on post-exercise recovery in both applications (p > 0.05). The LEDI improves performance only in the ipsilateral application, but there were no differences on [Lac] and cardiac autonomic responses after exercise for both the applications.

EFEITO AGUDO DO VOLUME DE ALONGAMENTO ESTÁTICO NO DESEMPENHO NEUROMUSCULAR DE JOVENS E IDOSAS

RESUMO Introdução: Os exercícios prévios de alongamento estático (AE) podem promover decréscimo transitório da força muscular. Características dos protocolos de AE e da amostra estudada podem interferir no desempenho neuromuscular subsequente às rotinas de alongamento. Objetivo: Investigar o efeito agudo de dois diferentes volumes de AE sobre o sistema neuromuscular de mulheres jovens e idosas durante a execução do leg press horizontal. Métodos: Vinte e quatro mulheres (12 jovens e 12 idosas), aparentemente saudáveis, compareceram ao local de realização do experimento em seis ocasiões distintas. Nas três primeiras visitas realizaram-se coleta dos dados pessoais, de dados antropométricos, familiarização com o protocolo de AE e registro de esforço isométrico no leg press horizontal. Nas três últimas visitas, foram realizados registros da curva força-tempo isométrica e atividade eletromiográfica (EMG) dos músculos vasto medial e vasto lateral após realização de uma de três condições experimentais: controle (sem alongamento), alongamento com volume total de 60 segundos e 120 segundos. A ordem das condições experimentais foi aleatorizada. O protocolo de AE envolveu três exercícios executados em duas séries de 30 segundos (AE60) ou em quatro séries de 30 segundos (AE120). O teste ANOVA two-way foi utilizado para análises dos dados. Resultados: Nenhuma das rotinas de AE acarretou alteração de taxa de desenvolvimento de força (TDF), contração voluntária máxima e atividade EMG nas mulheres jovens e idosas. Conclusões: Diferentes volumes de AE, em conformidade com recomendações atuais, não influenciaram o desempenho neuromuscular de mulheres jovens e idosas no exercício leg press horizontal.