scholarly journals Acute Effects of Intermittent Foot Cooling on 1 RM Leg Press Strength in Resistance-Trained Men: A Pilot Study

2021 ◽  
Vol 18 (18) ◽  
pp. 9594
Author(s):  
Chih-Min Wu ◽  
Mei-Hsien Lee ◽  
Wen-Yi Wang ◽  
Zong-Yan Cai
Keyword(s):  
Lower Limb ◽  
Repeated Measures ◽  
Vastus Lateralis ◽  
Crossover Design ◽  
Physiological Measures ◽  
Acute Effects ◽  
Leg Press ◽  
Recreational Athletes ◽  
Lower Limb Strength ◽  
Strength Based

Inter-set peripheral cooling can improve high-intensity resistance exercise performance. However, whether foot cooling (FC) would increase 1 repetition maximum (RM) lower-limb strength is unclear. This study investigated the effect of intermittent FC on 1 RM leg press strength. Ten recreational male lifters performed three attempts of 1 RM leg press with FC or non-cooling (NC) in a repeated-measures crossover design separated by 5 days. FC was applied by foot immersion in 10 °C water for 2.5 min before each attempt. During the 1 RM test, various physiological measures were recorded. The results showed that FC elicited higher 1 RM leg press strength (Δ [95% CI]; Cohen’s d effect size [ES]; 13.6 [7.6–19.5] kg; ES = 1.631) and electromyography values in vastus lateralis (57.7 [8.1–107.4] μV; ES = 0.831) and gastrocnemius (15.1 [−3.1–33.2] μV; ES = 0.593) than in NC. Higher arousal levels (felt arousal scale) were found in FC (0.6 [0.1–1.2]; ES = 0.457) than in NC. In conclusion, the preliminary findings, although limited, suggest intermittent FC has a potential ergogenic role for recreational athletes to enhance maximal lower-limb strength and may partly benefit strength-based competition events.

Effect of Acute Interset Foot Cooling on Lower Limb Strength Training Workout

2021 ◽  
Vol 16 (5) ◽  
pp. 682-687
Author(s):  
Zong-Yan Cai ◽  
Wen-Yi Wang ◽  
Yi-Ming Huang ◽  
Chih-Min Wu
Keyword(s):  
Repeated Measures ◽  
Perceived Exertion ◽  
Vastus Lateralis ◽  
Time Trial ◽  
Simple Main Effect ◽  
Rating Of Perceived Exertion ◽  
Training Experience ◽  
Leg Press ◽  
Lower Limb Strength ◽  
Main Effect

Purpose: The authors investigated the effect of foot cooling (FC) between sets in a leg press pyramid workout with resistance-trained participants. Methods: A total of 12 resistance-trained men (age = 21.8 [0.6] y; training experience = 1.7 [1] y) performed a pyramid workout, including 4 sets of 85% to 90% 1-repetition maximum leg press exercise to exhaustion with interset FC or noncooling in a repeated-measures crossover design separated by 5 days. The authors immersed the participants’ feet in 10°C water for 2.5 minutes between sets. Results: Two-way repeated-measures analysis of variance revealed that FC elicited significantly higher repetitions and electromyography (EMG) values of the vastus lateralis (simple main effect of condition) than did noncooling (P < .05) in the second (repetitions: 11 [3.5] vs 7.75 [3.2]; EMG: 63.4% [19.4%] vs 54.5% [18.4%]), third (repetitions: 8.9 [3.2] vs 6.4 [2.1]; EMG: 71.5% [17.4%] vs 60.6% [19.4%]), and fourth (repetitions: 7.5 [2.7] vs 5.1 [2.2]; EMG: 75.2% [19.6%] vs 59.3% [23.5%]) sets. The authors also detected a simple main effect of set in the FC and noncooling conditions on repetitions (P < .05) and in the FC condition on the vastus lateralis EMG values. Although the authors observed no time × trial interactions for the rating of perceived exertion, the authors observed main effects on the sets (7.7–9.6 vs 7.9–9.3, P < .05). Conclusions: Interset FC provides an ergogenic effect on a leg press pyramid workout and may offset fatigue, as indicated by higher repetitions and EMG response, without increasing perceived exertion.

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

2021 ◽  
pp. 194173812110163
Author(s):  
Isabel Martín-Fuentes ◽  
José M. Oliva-Lozano ◽  
José M. Muyor
Keyword(s):  
Repeated Measures ◽  
Muscle Activation ◽  
External Rotation ◽  
Vastus Lateralis ◽  
Maximum Velocity ◽  
Lower Limbs ◽  
Vastus Medialis ◽  
Kinetic Chain ◽  
Kinematic Parameters ◽  
Leg Press

Background: 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. Hypotheses: There will be no significant differences in muscle activation with regard to the feet position. The higher the MV, the greater the muscle activation. Study Design: A cross-sectional cohort study. Level of Evidence: Level 3. Methods: 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. Results: 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. Conclusion: The inclined leg press exercise produces the highest muscle activation in the vastus medialis, regardless of the velocity, feet stance, or gender. Clinical Relevance: 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.

The Reliability of the Lateral Step Test

2007 ◽  
Vol 16 (2) ◽  
pp. 131-142 ◽  
Author(s):  
Annabelle King ◽  
Mark Hancock ◽  
Joanne Munn
Keyword(s):  
Outcome Measures ◽  
Lower Limb ◽  
Repeated Measures ◽  
Research Laboratory ◽  
Close Agreement ◽  
Functional Performance ◽  
Step Test ◽  
Maximal Strength ◽  
Type Design ◽  
Lower Limb Strength

Context:Functional strength measures correlate more closely with functional performance than non-functional strength measures.Objectives:To determine the reliability of the lateral step test as a measure of maximal strength.Design:Intertester repeated measures.Setting:Research laboratory.Participants:Twenty four healthy, pain free subjects.Intervention:Two protocols (A and B) were evaluated. The protocols were identical except protocol B involved a three second pause. Participants performed a one repetition maximum (1RM) for each protocol on two occasions separated by one week.Main Outcome Measures:Step height (nearest cm) representingResults:Both protocols demonstrated excellent reliability, protocol A: ICC = 0.94 (95% CI, 0.87 to 0.97), SEM = 1.47 cm. Protocol B: ICC= 0.94 (95%CI, 0.85 to 0.97).Percent close agreement within 2 cm was 83.3% for protocol A and 79.1% for protocol B.Conclusion:Both protocols demonstrated excellent inter-tester reliability as measures of functional lower limb strength.

scholarly journals Electromyography, Stiffness and Kinematics of Resisted Sprint Training in the Specialized SKILLRUN® Treadmill Using Different Load Conditions in Rugby Players

Sensors ◽  
2021 ◽  
Vol 21 (22) ◽  
pp. 7482
Author(s):  
Antonio Martínez-Serrano ◽  
Elena Marín-Cascales ◽  
Konstantinos Spyrou ◽  
Tomás T. Freitas ◽  
Pedro E. Alcaraz
Keyword(s):  
Lower Limb ◽  
Repeated Measures ◽  
Muscle Activation ◽  
Vastus Lateralis ◽  
Biceps Femoris ◽  
Rugby Union ◽  
Sprint Training ◽  
Muscle Activation Patterns ◽  
Lower Limb Muscles ◽  
Load Conditions

This study’s aim was to analyze muscle activation and kinematics of sled-pushing and resisted-parachute sprinting with three load conditions on an instrumentalized SKILLRUN® treadmill. Nine male amateur rugby union players (21.3 ± 4.3 years, 75.8 ± 10.2 kg, 176.6 ± 8.8 cm) performed a sled-push session consisting of three 15-m repetitions at 20%, 55% and 90% body mas and another resisted-parachute session using three different parachute sizes (XS, XL and 3XL). Sprinting kinematics and muscle activity of three lower-limb muscles (biceps femoris (BF), vastus lateralis (VL) and gastrocnemius medialis (GM)) were measured. A repeated-measures analysis of variance (RM-ANOVA) showed that higher loads during the sled-push increased (VL) (p ≤ 0.001) and (GM) (p ≤ 0.001) but not (BF) (p = 0.278) activity. Furthermore, it caused significant changes in sprinting kinematics, stiffness and joint angles. Resisted-parachute sprinting did not change kinematics or muscle activation, despite producing a significant overload (i.e., speed loss). In conclusion, increased sled-push loading caused disruptions in sprinting technique and altered lower-limb muscle activation patterns as opposed to the resisted-parachute. These findings might help practitioners determine the more adequate resisted sprint exercise and load according to the training objective (e.g., power production or speed performance).

scholarly journals Assessment of the Multi-Location External Workload Profile in the Most Common Movements in Basketball

Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3441
Author(s):  
Carlos D. Gómez-Carmona ◽  
Sebastián Feu ◽  
José Pino-Ortega ◽  
Sergio J. Ibáñez
Keyword(s):  
Lower Limb ◽  
Repeated Measures ◽  
Ad Hoc ◽  
Physical Conditioning ◽  
Lumbar Region ◽  
Basketball Players ◽  
Eta Squared ◽  
Subject Variability ◽  
Acceleration And Deceleration ◽  
Linear Movement

The present study analyzed the multi-location external workload profile in basketball players using a previously validated test battery and compared the demands among anatomical locations. A basketball team comprising 13 semi-professional male players was evaluated in five tests (abilities/skills/tests): (a) aerobic, linear movement, 30-15 IFT; (b) lactic anaerobic, acceleration and deceleration, 16.25 m RSA (c) alactic anaerobic, curvilinear movement, 6.75 m arc (d) elastic, jump, Abalakov test (e) physical-conditioning, small-sided game, 10’ 3 vs.3 10 × 15 m. PlayerLoadRT was evaluated at six anatomical locations simultaneously (interscapular line, lumbar region, knees and ankles) by six WIMU PROTM inertial devices attached to the player using an ad hoc integral suit. Statistical analysis was composed of an ANOVA of repeated measures and partial eta squared effect sizes. Significant differences among anatomical locations were found in all tests with higher values in the location nearer to ground contact (p < 0.01). However, differences between lower limb locations were only found in curvilinear movements, with a higher workload in the outside leg (p < 0.01). Additionally, high between-subject variability was found in team players, especially at lower limb locations. In conclusion, multi-location evaluation in sports movements will make it possible to establish an individual external workload profile and design specific strategies for training and injury prevention programs.

scholarly journals COVID-19 era in long-term cardiac rehabilitation programs: how was muscle strenght and lean mass affected in cardiovascular patients?

2021 ◽  
Vol 28 (Supplement_1) ◽  
Author(s):  
M Borges ◽  
M Lemos Pires ◽  
R Pinto ◽  
G De Sa ◽  
I Ricardo ◽  
...  
Keyword(s):  
Muscle Strength ◽  
Cardiac Rehabilitation ◽  
Lean Mass ◽  
Lower Limb ◽  
Lower Limbs ◽  
Phase Iii ◽  
Face To Face ◽  
Home Based ◽  
Lower Limb Strength

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Exercise prescription is one of the main components of phase III Cardiac Rehabilitation (CR) programs due to its documented prognostic benefits. It has been well established that, when added to aerobic training, resistance training (RT) leads to greater improvements in peripheral muscle strength and muscle mass in patients with cardiovascular disease (CVD). With COVID-19, most centre-based CR programs had to be suspended and CR patients had to readjust their RT program to a home-based model where weight training was more difficult to perform. How COVID-19 Era impacted lean mass and muscle strength in trained CVD patients who were attending long-term CR programs has yet to be discussed. Purpose To assess upper and lower limb muscle strength and lean mass in CVD patients who had their centre-based CR program suspended due to COVID-19 and compare it with previous assessments. Methods 87 CVD patients (mean age 62.9 ± 9.1, 82.8% male), before COVID-19, were attending a phase III centre-based CR program 3x/week and were evaluated annually. After 7 months of suspension, 57.5% (n = 50) patients returned to the face-to-face CR program. Despite all constraints caused by COVID-19, body composition and muscle strength of 35 participants (mean age 64.7 ± 7.9, 88.6% male) were assessed. We compared this assessment with previous years and established three assessment time points: M1) one year before COVID-19 (2018); M2) last assessment before COVID-19 (2019); M3) the assessment 7 months after CR program suspension (last trimester of 2020). Upper limbs strength was measured using a JAMAR dynamometer, 30 second chair stand test (number of repetitions – reps) was used to measure lower limbs strength and dual energy x-ray absorptiometry was used to measure upper and lower limbs lean mass. Repeated measures ANOVA were used. Results Intention to treat analysis showed that upper and lower limbs lean mass did not change from M1 to M2 but decreased significantly from M2 to M3 (arms lean mass in M2: 5.68 ± 1.00kg vs M3: 5.52 ± 1.06kg, p = 0.004; legs lean mass in M2: 17.40 ± 2.46kg vs M3: 16.77 ± 2.61kg, p = 0.040). Lower limb strength also decreased significantly from M2 to M3 (M2: 23.31 ± 5.76 reps vs M3: 21.11 ± 5.31 reps, p = 0.014) after remaining stable in the year prior to COVID-19. Upper limb strength improved significantly from M1 to M2 (M1: 39.00 ± 8.64kg vs M2: 40.53 ± 8.77kg, p = 0.034) but did not change significantly from M2 to M3 (M2 vs M3: 41.29 ± 9.13kg, p = 0.517). Conclusion After CR centre-based suspension due to COVID-19, we observed a decrease in upper and lower limbs lean mass and lower limb strength in previously trained CVD patients. These results should emphasize the need to promote all efforts to maintain physical activity and RT through alternative effective home-based CR programs when face-to-face models are not available or possible to be implemented.

scholarly journals The Acute Effects of a Swimming Session on the Shoulder Rotators Strength and Balance of Age Group Swimmers

2021 ◽  
Vol 18 (15) ◽  
pp. 8109
Author(s):  
Nuno Batalha ◽  
Jose A. Parraca ◽  
Daniel A. Marinho ◽  
Ana Conceição ◽  
Hugo Louro ◽  
...  
Keyword(s):  
Repeated Measures ◽  
Training Session ◽  
Age Group ◽  
Acute Effects ◽  
Muscle Strengthening ◽  
Repeated Measures Design ◽  
Before And After ◽  
Shoulder Strength ◽  
Isometric Torque ◽  
Gender Specific

The purpose of this study was to analyze the acute effects of a standardized water training session on the shoulder rotators strength and balance in age group swimmers, in order to understand whether a muscle-strengthening workout immediately after the water training is appropriate. A repeated measures design was implemented with two measurements performed before and after a standardized swim session. 127 participants were assembled in male (n = 72; age: 16.28 ± 1.55 years, height: 174.15 ± 7.89 cm, weight: 63.97 ± 6.51 kg) and female (n = 55; age: 15.29 ± 1.28 years, height: 163.03 ± 7.19 cm, weight: 52.72 ± 5.48 kg) cohorts. The isometric torque of the shoulder internal (IR) and external (ER) rotators, as well as the ER/IR ratios, were assessed using a hand-held dynamometer. Paired sample t-tests and effect sizes (Cohen’s d) were used (p ≤ 0.05). No significant differences were found on the shoulder rotators strength or balance in males after training. Females exhibited unchanged strength values after practice, but there was a considerable decrease in the shoulder rotators balance of the non-dominant limb (p < 0.01 d = 0.366). This indicates that a single practice seems not to affect the shoulders strength and balance of adolescent swimmers, but this can be a gender specific phenomenon. While muscle-strengthening workout after the water session may be appropriate for males, it can be questionable regarding females. Swimming coaches should regularly assess shoulder strength levels in order to individually identify swimmers who may or may not be able to practice muscle strengthening after the water training.

scholarly journals Reliability of a New Portable Dynamometer for Assessing Hip and Lower Limb Strength

2021 ◽  
Vol 11 (8) ◽  
pp. 3391
Author(s):  
Jan Marušič ◽  
Goran Marković ◽  
Nejc Šarabon
Keyword(s):  
Lower Limb ◽  
External Rotation ◽  
Peak Torque ◽  
Knee Extension ◽  
Lower Limb Muscles ◽  
Lower Limb Strength ◽  
Flexion Extension ◽  
Strength Tests ◽  
Hip Abduction ◽  
Maximal Peak

The purpose of this study was to evaluate intra- and inter-session reliability of the new, portable, and externally fixated dynamometer called MuscleBoard® for assessing the strength of hip and lower limb muscles. Hip abduction, adduction, flexion, extension, internal and external rotation, knee extension, ankle plantarflexion, and Nordic hamstring exercise strength were measured in three sessions (three sets of three repetitions for each test) on 24 healthy and recreationally active participants. Average and maximal value of normalized peak torque (Nm/kg) from three repetitions in each set and agonist:antagonist ratios (%) were statistically analyzed; the coefficient of variation and intra-class correlation coefficient (ICC2,k) were calculated to assess absolute and relative reliability, respectively. Overall, the results display high to excellent intra- and inter-session reliability with low to acceptable within-individual variation for average and maximal peak torques in all bilateral strength tests, while the reliability of unilateral strength tests was moderate to good. Our findings indicate that using the MuscleBoard® dynamometer can be a reliable device for assessing and monitoring bilateral and certain unilateral hip and lower limb muscle strength, while some unilateral strength tests require some refinement and more extensive familiarization.

scholarly journals Central excitability does not limit postfatigue voluntary activation of quadriceps femoris

2006 ◽  
Vol 100 (6) ◽  
pp. 1757-1764 ◽  
Author(s):  
J. M. Kalmar ◽  
E. Cafarelli
Keyword(s):  
Evoked Potentials ◽  
Repeated Measures ◽  
Muscle Activation ◽  
Motor Evoked Potentials ◽  
Vastus Lateralis ◽  
Central Fatigue ◽  
Knee Extension ◽  
Voluntary Activation ◽  
Fatigue Protocol ◽  
Central Excitability

After fatigue, motor evoked potentials (MEP) elicited by transcranial magnetic stimulation and cervicomedullary evoked potentials elicited by stimulation of the corticospinal tract are depressed. These reductions in corticomotor excitability and corticospinal transmission are accompanied by voluntary activation failure, but this may not reflect a causal relationship. Our purpose was to determine whether a decline in central excitability contributes to central fatigue. We hypothesized that, if central excitability limits voluntary activation, then a caffeine-induced increase in central excitability should offset voluntary activation failure. In this repeated-measures study, eight men each attended two sessions. Baseline measures of knee extension torque, maximal voluntary activation, peripheral transmission, contractile properties, and central excitability were made before administration of caffeine (6 mg/kg) or placebo. The amplitude of vastus lateralis MEPs elicited during minimal muscle activation provided a measure of central excitability. After a 1-h rest, baseline measures were repeated before, during, and after a fatigue protocol that ended when maximal voluntary torque declined by 35% (Tlim). Increased prefatigue MEP amplitude ( P = 0.055) and cortically evoked twitch ( P < 0.05) in the caffeine trial indicate that the drug increased central excitability. In the caffeine trial, increased MEP amplitude was correlated with time to task failure ( r = 0.74, P < 0.05). Caffeine potentiated the MEP early in the fatigue protocol ( P < 0.05) and offset the 40% decline in placebo MEP ( P < 0.05) at Tlim. However, this was not associated with enhanced maximal voluntary activation during fatigue or recovery, demonstrating that voluntary activation is not limited by central excitability.

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