Inclined Leg Press Research Articles

High-load and low-volume warm-up increases performance in a resistance training session

IntroductionA warm-up is recommended prior to performing a resistance training workout. Understanding the dose-response effect of warm-up load intensities can contribute to subsequent workout performance. The aim of this study was to compare different warm-up load intensities on subsequent resistance training volume in a workout. MethodsFifteen men who had at least six months of resistance training experience were evaluated. Three resistance training sessions were performed with warm-up load intensities of 40%, 60%, and 80% of the ten-repetition maximum was applied for 15, 10 and 5 repetitions, respectively. Each session consisted of the bench press, inclined leg press, and wide grip lat pulldown exercises performed for three sets to failure with 2 min rest between sets and exercises. ResultsThe 80% warm-up resulted in significantly greater total training volume (TTV) when compared to the 60% (p = 0.010) and 40% (p = 0.038) conditions. In addition, volume load and repetition performance were greater in the 80% condition versus the 60% condition for the bench press (p = 0.037 and p = 0.015, respectively). For the inclined leg press, the difference was close to significance with a probability value of p = 0.055 when comparing the 80% versus 40% protocols. ConclusionBefore starting a resistance training session, it is recommended that a warm-up for each exercise be performed at 80% of the initial workout load.

Reduction in re-rupture rates following implementation of return-to-sport testing after anterior cruciate ligament reconstruction in 313 patients with a mean follow-up of 50 months

Objectives:The objective of this study was to assess the mid-term effectiveness of a return to sport (RTS) test in relation to preventing anterior cruciate ligament (ACL) re-rupture and contralateral ACL injury following ACL reconstruction (ACLR). Furthermore, this study aimed to assess the timing of passing a, RTS-test after surgery, and the effect age has on RTS outcomes. Methods:Patients undergoing ACLR between August 2014 and December 2018 took an RTS-test following rehabilitation. The RTS-test consisted of the Anterior Cruciate Ligament Return to Sport After Injury Scale, a single-leg hop, a single-leg triple hop, a single-leg triple cross-over hop, a box-drop vertical jump down, a single-leg 4-rep max-incline leg press, and a modified agility T test. RTS-passing criteria were ≥90% limb symmetry index in addition to defined takeoff and landing parameters. Mid-term review assessed sporting level, ACL re-injury, and contralateral ACL injury. ResultsA total of 352 patients underwent RTS-testing, following ACLR with 313 (89%) contactable at follow-up, a mean of 50 months (standard deviation: 11.41, range: 28–76) after surgery. The re-rupture rate was 6.6% after passing the RTS-test and 10.3% following failure (p ​= ​0.24), representing a 36% reduction. Contralateral ACL injury rate after surgery was 6% and was 19% lower in those passing the RTS test. The mean age of patients passing their first RTS-test was significantly higher than that of those who failed (p ​= ​0.0027). Re-ruptures in those who passed the RTS test first time occurred late (>34 months), compared to those who failed first time, which all occurred early (<33 months) (p ​= ​0.0015). The mean age of re-rupture was significantly less than those who did not sustain a re-rupture (p ​= ​0.025). Conclusion:Passing a RTS-test following ACLR reduces ACL re-rupture by 36.21% and contralateral ACL injury by 19.15% at mid-term follow-up. Younger patients are more likely to fail a RTS-test and are at higher risk of contralateral ACL rupture.Level III Evidence.

Backseat Inclination Affects the Myoelectric Activation During the Inclined Leg Press Exercise in Recreationally Trained Men.

Marchetti, PH, Gomes, WA, Da Silva, JJ, Magalhaes, RA, Teixeira, LFM, and Whiting, WC. Backseat inclination affects the myoelectric activation during the inclined leg press exercise in recreationally trained men. J Strength Cond Res 37(10): e541-e545, 2023-Changes in the angle between the seat and backrest during the inclined leg press (ILP) exercise may influence myoelectric activity. The purpose of this study was to evaluate the myoelectric activity between 2 different angles between the seat and backrest (90° and 125°) during the ILP exercise in recreationally trained men. Fifteen young, resistance-trained men (age: 26.8 ± 5.3 years, height: 173.8 ± 6.6 cm, total body mass: 81.6 ± 7.6 kg) performed 1 set of 10 repetitions at 70% of their body mass during the ILP exercise using 2 different angles between the seat and backrest (ILP90° and ILP125°). Surface electromyography (peak RMS 90 and iEMG) was used to measure the myoelectric activity of the vastus lateralis (VL), biceps femoris (BF), and gluteus maximus (GM). A paired t test was used to measure differences in knee and hip joint displacement, peak RMS 90 , and iEMG between ILP90 and ILP125. The hip angle presented a greater displacement during the ILP125 when compared with ILP90 ( p < 0.001), considering a similar knee joint displacement. For the VL, there was observed greater myoelectric activation (peak RMS 90 and iEMG) during ILP125 when compared with ILP90 ( p < 0.05). For the BF, there was observed greater myoelectric activation (peak RMS 90 and iEMG) during ILP90 when compared with ILP125 ( p < 0.05). However, GM did not present differences between ILP90 and ILP125. In conclusion, the angle between the seat and backrest (ILP90 or ILP125) altered the myoelectric activation of the VL and BF with no difference for the GM.

Evaluation of load-velocity relationships in the inclined leg press exercise: A comparison between genders

The objectives of this study were threefold: (i) to analyze the load-velocity relationships between mean propulsive velocity (MPV), mean velocity (MV), peak velocity (PV), and relative load during the inclined leg press exercise; (ii) to analyze the differences in the load-velocity relationships between males and females; and (iii) to determine gender-specific predictive equations for loads between 50%–100% one-repetition maximum (1RM) in a population of trained young college students. The load-velocity relationships of 15 males and 13 females were explored through a progressive loading test, up to the individual 1RM load. Gender-specific load-velocity relationships were plotted along with the individual relationships. High to very high associations were found for gender-specific load-MPV and load-MV relationships, whereas load-PV presented moderate associations. The gender-specific load-velocity relationships in males were steeper than in females for MPV, MV and PV. However, individual load-velocity relationships presented higher associations than gender-specific relationships for all subjects. Finally, the predicted velocity outcomes for each %1RM load were always significantly higher in males than in females, except for PV at 95% and 100% 1RM load. Taken collectively, the findings from the present study support the application of subject-specific and gender-specific load-velocity relationships, highlighting the disparities between male and female relationships. Les objectifs de cette étude étaient triples : (i) analyser les relations force vitesse entre la vitesse de propulsion moyenne (MPV), la vitesse moyenne (VM), la vitesse de pointe (PV) et la charge relative pendant l’exercice de presse a cuisses inclinée ; (ii) analyser les différences dans les relations force-vitesse entre les hommes et les femmes ; et (iii) déterminer des équations prédictives spécifiques à chaque sexe pour des charges comprises entre 50 % et 100 % maximum d’une répétition (1RM) dans une population de jeunes étudiants entraînés. Les relations force-vitesse de 15 garçons et 13 filles ont été examinées grâce à un test de charge progressive, jusqu’à la charge individuelle 1RM. Les relations force-vitesse spécifiques au sexe ont été comparée aux relations individuelles. Des associations élevées à très élevées ont été trouvées pour les relations charge-MPV et charge-VM spécifiques au sexe, tandis que charge-PV présentait des associations modérées. Les relations force-vitesse spécifiques au sexe chez les hommes présentaient une pente plus prononcée que chez les femmes pour MPV, MV et PV. Cependant, les relations charge-vitesse individuelles présentaient des associations plus élevées que les relations spécifiques au sexe pour tous les sujets. Enfin, les résultats de vitesse prédits pour chaque charge %1RM étaient toujours significativement plus élevés chez les hommes que chez les femmes, à l’exception de PV à 95 % et 100 % de charge 1RM. Au total, les résultats de la présente étude plaident pour l’utilisation de relations force-vitesse personnalisées en fonction des caractéristiques du sujet et de son sexe, montrant une différence nette entre garçons et filles.

Influence of Feet Position and Execution Velocity on Muscle Activation and Kinematic Parameters During the Inclined Leg Press Exercise.

The leg press is one of the most typical exercises for strengthening the lower limbs. The objectives of this study were to compare 5 inclined leg press exercise conditions, varying the feet width stance (100% or 150% hip width), the feet rotation (0° or 45° external rotation) on the footplate and using 2 different movement velocities (MVs; maximum intended, and 2:2 seconds steady-paced velocities) to determine their effect on muscle activation as well as on the kinematic parameters between trained men and trained women. There will be no significant differences in muscle activation with regard to the feet position. The higher the MV, the greater the muscle activation. A cross-sectional cohort study. Level 3. A repeated-measures between-group design was performed to examine muscle activation and kinematic parameters for the different conditions between gender groups. The level of significance was set at alpha = 0.05 for all statistical analyses. Muscle activation presented no differences between conditions regarding feet width stance or feet rotation. Furthermore, muscle activation was greater during positive phases than negative phases of the exercise for all conditions and was also greater under maximum intended velocity conditions compared with steady-paced conditions. Otherwise, the muscle activation pattern presented slight differences by gender. In men, the greatest muscle activation was for the vastus medialis, followed by the vastus lateralis (VL), rectus femoris (RF), and gluteus medialis (GMED), while in women, the greatest muscle activation was for the vastus medialis, followed by the RF, VL, and GMED. Finally, greater mean propulsive velocity, maximum velocity, maximum power, and footplate displacement values were reported for men than for women under all the conditions. The inclined leg press exercise produces the highest muscle activation in the vastus medialis, regardless of the velocity, feet stance, or gender. Given that there are no differences in muscle activation regarding the feet stance, a participant's preferred feet stance should be encouraged during the inclined leg press exercise. Furthermore, the MV would preferably depend on the session objective (a training or a rehabilitation program), being aware that there is greater muscle activation at higher speeds. The inclined leg press exercise could be performed as a closed kinetic chain exercise when the main objective is to activate the vastus medialis.

Stretch-Shortening Cycle Potentiation and Resistance Training-Induced Changes in Walking Economy/Ease and Activity-Related Energy Expenditure in Older Women.

Hunter, GR, Singh, H, Martins, C, Baranauskas, MN, and Carter, SJ. Stretch-shortening cycle potentiation and resistance training-induced changes in walking economy/ease and activity-related energy expenditure in older women. J Strength Cond Res 35(5): 1345-1349, 2021-Use of elastic energy to improve economy and ease of walking may be important for older adults. The purpose of this investigation was to determine whether baseline (i.e., untrained) stretch-shortening cycle potentiation (SSCP) was associated with potential changes in free-living activity-related energy expenditure (AEE) after supervised exercise training. Sedentary, postmenopausal women (n = 64) between 60 and 74 years of age were evaluated before and after 16 weeks of combined aerobic and resistance training. Assessments included: (a) body composition (dual-energy X-ray absorptiometry), (b) resting energy expenditure (indirect calorimetry), (c) submaximal and maximal walking (treadmill/indirect calorimetry), (d) total energy expenditure (doubly labeled water), and (e) one repetition maximum performed on an incline leg press and SSCP (calculated as the difference between concentric and countermovement leg press throw). Results indicated that baseline SSCP was related (r = -0.29; p < 0.02) to changes in AEE. However, subjects who possessed a high baseline SSCP did not increase SSCP or AEE, whereas subjects with low to moderate baseline SSCP demonstrated a significant increase in both SSCP (low +0.54 and moderate +0.47 m·s-1) and AEE (low +158 and moderate +333 kcal·d-1) post-training (all p less than 0.05). Our findings suggest that among subjects with low to moderate baseline SSCP, 16 weeks of combined aerobic and resistance training can increase SSCP and free-living AEE. However, subjects with high baseline SSCP may require tailored exercise to increase SSCP and possibly AEE.

Muscle Activation and Kinematic Analysis during the Inclined Leg Press Exercise in Young Females.

Knee joint muscle activation imbalances, especially weakness in the vastus medialis oblique, are related to patellofemoral pain within the female population. The available literature presents the leg press as an exercise which potentially targets vastus medialis oblique activation, thus reducing imbalances in the quadriceps muscles. The main aim of the present study was to compare thigh muscle activation and kinematic parameters under different conditions during the inclined leg press exercise in a young female population. A cross-sectional study was conducted on 10 young, trained females. Muscle activation of the vastus medialis oblique, vastus lateralis, rectus femoris and gluteus medialis was analyzed under five different inclined leg press conditions, modifying the feet rotation (0–45° external rotation) and the stance width (100–150% hip width) on the footplate. All the conditions were performed at two different movement velocities: controlled velocity (2″ eccentric–2″ concentric) and maximal intended velocity. Mean propulsive velocity, maximum velocity and maximum power were also assessed. The results show that both controlled velocity conditions and maximal intended velocity conditions elicited a similar muscle activation pattern with greater activation during the concentric phase (p < 0.001, ηp2 = 0.96). The maximal intended velocity conditions showed greater overall muscle activation (p < 0.001, ηp2 = 0.91). The vastus medialis oblique presented the greatest muscle activation, followed by the rectus femoris, vastus lateralis and, the gluteus medialis. Furthermore, the inclined leg press condition with 0º feet rotation, 100% hip width distance and the maximal intended velocity generated the greatest kinematic parameter outputs. In conclusion, the inclined leg press exercise might be an optimal exercise to target vastus medialis activation regardless of the feet rotation and stance width conditions.

Are wearable heart rate measurements accurate to estimate aerobic energy cost during low-intensity resistance exercise?

The aim of the present study was to assess the accuracy of heart rate to estimate energy cost during eight resistance exercises performed at low intensities: half squat, 45° inclined leg press, leg extension, horizontal bench press, 45° inclined bench press, lat pull down, triceps extension and biceps curl. 56 males (27.5 ± 4.9 years, 1.78 ± 0.06 m height, 78.67 ± 10.7 kg body mass and 11.4 ± 4.1% estimated body fat) were randomly divided into four groups of 14 subjects each. Two exercises were randomly assigned to each group and subjects performed four bouts of 4-min constant-intensity at each assigned exercise: 12%, 16%, 20% and 24% 1-RM. Exercise and intensity order were random. Each subject performed no more than 2 bouts in the same testing session. A minimum recovery of 24h was kept between sessions. During testing VO2 was measured with Cosmed K4b2 and heart rate was measured with Polar V800 monitor. Energy cost was calculated from mean VO2 during the last 30-s of each bout by using the energy equivalent 1 ml O2 = 5 calorie. Linear regressions with heart rate as predictor and energy cost as dependent variable were build using mean data from all subjects. Robustness of the regression lines was given by the scatter around the regression line (Sy.x) and Bland-Altman plots confirmed the agreement between measured and estimated energy costs. Significance level was set at p≤0.05. The regressions between heart rate and energy cost in the eight exercises were significant (p<0.01) and robustness was: half squat (Sy.x = 0,48 kcal·min-1), 45° inclined leg press (Sy.x = 0,54 kcal·min-1), leg extension (Sy.x = 0,59 kcal·min-1), horizontal bench press (Sy.x = 0,47 kcal·min-1), 45° inclined bench press (Sy.x = 0,54 kcal·min-1), lat pull down (Sy.x = 0,28 kcal·min-1), triceps extension (Sy.x = 0,08 kcal·min-1) and biceps curl (Sy.x = 0,13 kcal·min-1). We conclude that during low-intensity resistance exercises it is possible to estimate aerobic energy cost by wearable heart rate monitors with errors below 10% in healthy young trained males.

Familiarisation, reproducibility, sensitivity and joint angle specificity of bilateral isometric force exertions during leg press

BACKGROUND: Strength assessments are used to monitor physical progression and evaluate the impact of training interventions, which is extremely valuable for both athletic performance and clinical populations. For results to be useful, measurements must be relevant, reliable and show sensitivity to change. OBJECTIVES: The aim was to establish the practicality of isometric force assessment at two different knee-joint angles; 90° (ISO90) and 120° (ISO120). More specifically, to address the familiarisation effects, reproducibility and sensitivity of measurements associated with each method of assessment, and the discrepancy in force output when altering the angle at the knee joint. METHODS: Thirty-five strength trained males attended three sessions; familiarisation (T1), test (T2) and retest (T3), separated by 7 days. During each session, ISO90 and ISO120 was assessed using an incline leg press device. RESULTS: Force output was similar during T1, T2 and T3 for ISO90 and ISO120, separately (p > 0.05). Measurements taken from both assessment methods demonstrated good reproducibility (ICC = 0.96, CV < 5%) and showed sufficient sensitivity to detect changes in performance. Force output was greater during ISO120 (5153 ± 1446 N) versus ISO90 (2660 ± 597 N, p < 0.001) but the magnitude of the difference in force output showed great intrasubject variability. CONCLUSION: Isometric assessment performed on a leg press device requires minimal habituation to demonstrate a good degree of reproducibility and sensitivity to detect small changes in performance. It is a simple and practical method to evaluate strength at different joint angles, which may prove useful in strength diagnosis in performance and clinical contexts.

Eccentric cycling emphasising a low cardiopulmonary demand increases leg strength equivalent to workload matched concentric cycling in middle age sedentary males

ObjectivesThis study determined if eccentric endurance cycling, eliciting a low cardiovascular demand, could stimulate muscle strength adaptations in sedentary middle-aged males. DesignTwenty-four middle-aged sedentary males were allocated to concentric (CON) or matched workload eccentric (ECC) cycling (60% peak concentric workload) according to their maximal voluntary isometric quadriceps strength. MethodsSeventeen participants [42.7±8.3 years, BMI 28.6±5.2, peak oxygen consumption [30.5±5.8mLkg−1min−1] completed 8 weeks (2 sessions per week) of CON (n=8) or ECC (n=9) cycle training. Incline leg press (6RM), maximal voluntary isometric contraction (MVIC) torque of the quadriceps and peak oxygen consumption were measured at baseline and 8 weeks. ResultsEccentric cycle training resulted in low cardiovascular demand (CON 154±2; ECC 95±3bmin−1P<0.05) and ratings of perceived exertion (CON 14.9±0.3; ECC 9.5±0.3/20 P<0.05). Peak oxygen consumption improved within the CON group (Baseline 27.4±2.1; 8 weeks: 30.0±1.7mLkg−1min−1P<0.05) and not within the ECC group (Baseline 33.2±1.5; 8 weeks 33.3±1.6mLkg−1min−1) following training. 6RM (CON 176±20; ECC 192±11kg) and MVIC (CON 199±25; ECC 199±25Nm) strength were equivalent at baseline (P>0.05). Both groups significantly increased 6RM (CON 13.0±3.0; ECC 10.7±3.2%) and MVIC (CON 12.9±4.3; ECC 18.8±3.0%) relative to their own baseline (P<0.05). Therefore, improved leg strength was equivalent between CON and ECC groups despite the varied training (P>0.05). ConclusionsIn sedentary middle age males, eccentric endurance cycling with a low cardiovascular demand, increased both quadriceps isometric and 6RM strength comparable to a matched workload concentric cycling program.

Energy cost of isolated resistance exercises across low- to high-intensities.

This study aimed to estimate the energy cost across various intensities at eight popular resistance exercises: half squat, 45° inclined leg press, leg extension, horizontal bench press, 45° inclined bench press, lat pull down, triceps extension and biceps curl. 58 males (27.5 ± 4.9 years, 1.78 ± 0.06 m height, 78.67 ± 10.7 kg body mass and 11.4 ± 4.1% estimated body fat) were randomly divided into four groups of 14 subjects each. For each group, two exercises were randomly assigned and on different days, they performed four bouts of 5-min constant-intensity for each of the two assigned exercises: 12%, 16%, 20% and 24% 1-RM. Later, the subjects performed exhaustive bouts at 80% 1-RM in the same two exercises. The mean values of VO2 at the last 30s of exercise at 12, 16, 20 and 24% 1-RM bouts were plotted against relative intensity (% 1-RM) in a simple linear regression mode. The regressions were then used to predict O2 demand for the higher intensity (80% 1-RM). Energy cost rose linearly with exercise intensity in every exercise with the lowest mean values were found in biceps curl and the highest in half squat exercise (p<0.001). Half squat exercise presented significant (p<0.001) higher values of energy cost in all intensities, when compared with the remaining exercises. This study revealed that low-intensity resistance exercise provides energy cost comprised between 3 and 10 kcal∙min-1. Energy cost rose past 20 kcal∙min-1 at 80% 1-RM in leg exercise. In addition, at 80% 1-RM, it was found that upper body exercises are less anaerobic than lower-body exercises.

Comparison of Multiple Sets and Single Set of Resistance Training on Muscle Strength and Power

Studies have been conducted to investigate the effects of different resistance training modalities on muscle strength and power in order to improve physical performance, yet to date findings have been inconclusive. Optimal resistance programs for muscular responses to high and low volume resistance training still need to be explored. PURPOSE: The purpose of this study was to compare the effects of multiple sets (70% of 1RM, 3 sets/10 reps) and a single set (50-100% of 1RM, 1 set/8 reps) of resistance training on muscular strength and power in healthy male college students. METHODS: A total of 19 students were randomly assigned to either a single set (ST, n=6), multiple sets (MT, n=7), or control group (CON, n=6). The ST (every 3rd day) and MT (3x/week) trained for 8 weeks using an inclined leg press. The ST training protocol consisted of 50%, 75%, 90%, and 100% of previous maximal loads. During the additional training repetitions (up to 8th reps), 10lb was added each rep until a new maximal load was achieved. Total volume of ST was 168 reps (8 reps x 21 days), and MT was 720 reps (30 reps x 24 days). One-repetition maximum, muscle maximal voluntary contraction, peak power, and electromyography were measured at baseline and after 8 weeks of training. A repeated-measured ANOVAs were used to find interaction effect between trial and treatment groups factors. RESULTS: 1RM was significantly increased in all training groups compared to the baseline (p < .001). There was no significant different on 1RM between two training groups after 8 weeks of training sessions. Muscle maximal voluntary contraction (p < .001) and electromyography (p = .043) were significantly increased in MT after 8 weeks of training compared to baseline, but not in ST (p = .089 and p = .206, respectively). There was no significant increase on peak power after 8 weeks of resistance training compared to baseline with MT (p = .286) or ST (p = .372). DISCUSSION: The single set protocol is an effective as traditional multiple sets resistance training for increasing muscle strength with less total volume of training compared to the multiple sets protocol.

Effects of resistance exercise order on the number of repetitions performed to failure and perceived exertion in untrained young males.

Exercise order is an essential variable of resistance training (RT) programs which is usually related to repetition performance. The purpose of this study was to investigate the acute effect of different resistance exercise order on the number of repetitions performed to failure and related ratings of perceived exertion (RPE). Thirteen male adolescents (age: 14.46 ± 1.39 years, body height: 165.31 ± 12.75 cm, body mass: 58.73 ± 12.27 kg, estimated body fat: 21.32 ± 2.84%), without previous experience in RT, performed four resistance exercises: incline leg press (ILP), dumbbell lunge (DL), bench press (BP) and lying barbell triceps extension (TE) in two sequences - Sequence A (SEQA): ILP, DL, BP and TE; sequence B (SEQB): ILP, BP, DL and TE. The exercise sequences were performed in a randomized crossover design with a rest interval of 72h between sessions. Within-subjects analysis showed significant differences in the number of repetitions performed to failure in both sequences, but not in the RPE. Post-hoc tests revealed significant decrements in the number of repetitions from the first to the remaining exercises in both sequences. However, pairwise comparisons did not indicate significant differences between the same exercises performed in different sequences. In conclusion, the results of the current study in adolescents suggest that the main exercises should be performed at the beginning of the RT session.

Muscle Adaptations to Plyometric vs. Resistance Training in Untrained Young Men

The purpose of this study was to compare changes in muscle strength, power, and morphology induced by conventional strength training vs. plyometric training of equal time and effort requirements. Young, untrained men performed 12 weeks of progressive conventional resistance training (CRT, n = 8) or plyometric training (PT, n = 7). Tests before and after training included one-repetition maximum (1 RM) incline leg press, 3 RM knee extension, and 1 RM knee flexion, countermovement jumping (CMJ), and ballistic incline leg press. Also, before and after training, magnetic resonance imaging scanning was performed for the thigh, and a muscle biopsy was sampled from the vastus lateralis muscle. Muscle strength increased by approximately 20-30% (1-3 RM tests) (p < 0.001), with CRT showing 50% greater improvement in hamstring strength than PT (p < 0.01). Plyometric training increased maximum CMJ height (10%) and maximal power (Pmax; 9%) during CMJ (p < 0.01) and Pmax in ballistic leg press (17%) (p < 0.001). This was far greater than for CRT (p < 0.01), which only increased Pmax during the ballistic leg press (4%) (p < 0.05). Quadriceps, hamstring, and adductor whole-muscle cross-sectional area (CSA) increased equally (7-10%) with CRT and PT (p < 0.001). For fiber CSA analysis, some of the biopsies had to be omitted. Type I and IIa fiber CSA increased in CRT (n = 4) by 32 and 49%, respectively (p < 0.05), whereas no significant changes occurred for PT (n = 5). Myosin heavy-chain IIX content decreased from 11 to 6%, with no difference between CRT and PT. In conclusion, gross muscle size increased both by PT and CRT, whereas only CRT seemed to increase muscle fiber CSA. Gains in maximal muscle strength were essentially similar between groups, whereas muscle power increased almost exclusively with PT training.

Effects of weight lifting training combined with plyometric exercises on physical fitness, body composition, and knee extension velocity during kicking in football

The effects of a training program consisting of weight lifting combined with plyometric exercises on kicking performance, myosin heavy-chain composition (vastus lateralis), physical fitness, and body composition (using dual-energy X-ray absorptiometry (DXA)) was examined in 37 male physical education students divided randomly into a training group (TG: 16 subjects) and a control group (CG: 21 subjects). The TG followed 6 weeks of combined weight lifting and plyometric exercises. In all subjects, tests were performed to measure their maximal angular speed of the knee during in-step kicks on a stationary ball. Additional tests for muscle power (vertical jump), running speed (30 m running test), anaerobic capacity (Wingate and 300 m running tests), and aerobic power (20 m shuttle run tests) were also performed. Training resulted in muscle hypertrophy (+4.3%), increased peak angular velocity of the knee during kicking (+13.6%), increased percentage of myosin heavy-chain (MHC) type IIa (+8.4%), increased 1 repetition maximum (1 RM) of inclined leg press (ILP) (+61.4%), leg extension (LE) (+20.2%), leg curl (+15.9%), and half squat (HQ) (+45.1%), and enhanced performance in vertical jump (all p < or = 0.05). In contrast, MHC type I was reduced (-5.2%, p < or = 0.05) after training. In the control group, these variables remained unchanged. In conclusion, 6 weeks of strength training combining weight lifting and plyometric exercises results in significant improvement of kicking performance, as well as other physical capacities related to success in football (soccer).

Neutralisation of muscle tumour necrosis factor alpha does not attenuate exercise-induced muscle pain but does improve muscle strength in healthy male volunteers

Objective:Inflammatory mediators, such as tumour necrosis factor alpha (TNFα), may contribute to delayed-onset muscle soreness. The effect of neutralising TNFα with etanercept, a soluble TNFα receptor, on delayed-onset muscle soreness...

Counter Movement Jump Characteristics Pre and Post Fatiguing Strength Exercise in Elderly Individuals

Failure to perform functional motor task in elderly individuals may be linked to muscle fatigue. Leg muscle peak power generation obtained during counter movement jump (CMJ) test has previously demonstrated close correlations to various functional motor tasks in old individuals. It is not known, however, which impact fatiguing leg strength exercise has on the various descriptive parameters of the CMJ-test. PURPOSE: To examine changes in CMJ parameters pre and post fatiguing leg strength exercise in elderly women and to correlate changes in jump height and mechanical CMJ output, respectively. METHODS: Eighteen elderly women (age 69.7 ±3.4 years, mean ± SD) were randomly assigned CMJ tests with or without prior fatiguing leg muscle exercise. The fatiguing protocol consisted of 5 sets of 10 RM incline leg press. Maximal CMJs were performed on a force plate (Kistler 9281 B). Peak upward acceleration (apeak) was measured in the eccentric phase, while maximal jump height (JH), peak power (Ppeak) and mean power (Pmean) were calculated for concentric phase. Ppeak was further decomposed into its velocity (Vppeak) and force (Fppeak) components. Furthermore, plantar flexor phase mean power (PF Pmean) was denned in the final part of the concentric phase where the position of the center of mass is lifted vertically above the starting position. A separate familiarization session was performed 1–4 days prior to the test session. Students paired t-test was used to evaluate differences in mean values pre versus post fatiguing leg exercise and linear correlation of JH-changes and descriptive parameters were evaluated by the Pearson product-moment method. RESULTS: A significant decrease in JH (−9.3%) was followed by decreases in Pmean (−3.8%), Vppeak (−2.9%), and apeak (−20.4%). When correlating the decrease in JH with the decreases in mechanical CMJ output the Pmean and PF Pmean explained a large proportion of the variation in JH-decrease (77.6% and 84.6%, respectively). Moderate correlations were observed for Ppeak, Vppeak, and apeak (range: 24.8% and 30.2%). CONCLUSIONS: Changes in PF Pmean and Pmean largely explained the decrease in JH. Fatigue related decrements in plantar flexor function and functional consequences of muscle fatigue should be evaluated further in elderly subjects.

EFFECTS OF CREATINE MONOHYDRATE SUPPLEMENTATION ON BODY COMPOSITION AND STRENGTH INDICES IN EXPERIENCED RESISTANCE TRAINED WOMEN

The purpose of this study was to examine 10 weeks of creatine monohydrate (Cr) supplementation coupled with resistance training on body composition and strength in women trainees. Twenty-six subjects ingested Cr (n = 13) or a placebo (Pl) (n = 13) at a dose of 0.3 g·kg−1 and 0.03 g·kg−1 body mass for the initial 7 days and subsequent 9 weeks, respectively, while performing a resistance training program 4 days per week. Significant increases (p < 0.05) occurred in both groups for lean body mass and 1 repetition maximum (1RM) bench press and incline leg press. There was a significant main effect for training, but there was no significant difference in the total number of repetitions completed after 5 sets of multiple repetitions to exhaustion at 70% of 1RM for bench press and incline leg press for both groups or in the ability to perform a greater training volume (sets × repetitions × load) in the Cr vs. Pl groups over the 10 weeks. The results indicate that Cr supplementation combined with 10 weeks of concurrent resistance training may not improve strength or lean body mass greater than training only. These findings may be a result of nonresponders due to gender differences or a varying biological potential to uptake Cr within the muscle.

Effects of Creatine Monohydrate Supplementation on Body Composition and Strength Indices in Experienced Resistance Trained Women

The purpose of this study was to examine 10 weeks of creatine monohydrate (Cr) supplementation coupled with resistance training on body composition and strength in women trainees. Twenty-six subjects ingested Cr (n = 13) or a placebo (Pl) (n = 13) at a dose of 0.3 g.kg(-1) and 0.03 g.kg(-1) body mass for the initial 7 days and subsequent 9 weeks, respectively, while performing a resistance training program 4 days per week. Significant increases (p < 0.05) occurred in both groups for lean body mass and 1 repetition maximum (1RM) bench press and incline leg press. There was a significant main effect for training, but there was no significant difference in the total number of repetitions completed after 5 sets of multiple repetitions to exhaustion at 70% of 1RM for bench press and incline leg press for both groups or in the ability to perform a greater training volume (sets x repetitions x load) in the Cr vs. Pl groups over the 10 weeks. The results indicate that Cr supplementation combined with 10 weeks of concurrent resistance training may not improve strength or lean body mass greater than training only. These findings may be a result of nonresponders due to gender differences or a varying biological potential to uptake Cr within the muscle.

Effects Of Six-weeks Of Weight-lifting And Plyometric Exercises On Muscle Mass And Vertical Jump Performance

PURPOSE To determine the effect of 6 six weeks of weight-lifting training combined with plyometric exercises on vertical jump performance and maximal strength. METHODS Thirty-four physical educations students (24.2 ± 0.4 yr, mean ± SEM) were randomly assigned to the training group (TG, n = 15) or non-training control group (CG, n = 19). TG subjects trained 3 times per week during 6 weeks by weight lifting and plyometric exercises. During a countermovement vertical jump (CMJ) height jumped (VJH), rate force development (RFD), mechanical positive impulse (MPI), peak power (PP), mean power (MP), maximal force (MF) were assessed with a force plate. Similarly, 1 RM of incline leg press (ILP), leg extension (LE) and half squat (HS) were calculated. Leg lean mass (LLM) was assessed by DXA. Differences were established using the corresponding statistical Student's t tests (p<0.05). The influence of lean mass changes on performance was assessed using bivariate correlation analysis. RESULTS Significant differences were found in all CMJ related variables except in MF in the TG compared to the CG (table 1). In addition, the TG increased significantly the 1 RM in every exercise and LLM with training (table 1). Furthermore, LLM increased by a third more in TG than in GC (p<0.05). No correlation was found between LLM development and the enhancement of either 1RM performance or CMJ-related variables.Table 1: Changes in 1 RM and CMJ in the training and the control groups (mean ± SEM). *P <0.05 between groups; $P <0.05 intragroup difference before and after training.CONCLUSION 6-weeks strength training combined with plyometric exercises enhances leg muscle mass and improves both, maximal dynamic force (1 RM) and countermovement performance in physical education students. Granted by Gobierno de Canarias Gobierno de Canarias (PI2000/067) and Ministerio de Educación, Cultura y Deportes (AP2000-3652).