scholarly journals Inspiratory and Lower-Limb Strength Importance in Mountain Ultramarathon Running. Sex Differences and Relationship with Performance

Sports ◽  
2020 ◽  
Vol 8 (10) ◽  
pp. 134
Author(s):  
Ignacio Martinez-Navarro ◽  
Antonio Montoya-Vieco ◽  
Eladio Collado ◽  
Bárbara Hernando ◽  
Carlos Hernando
Keyword(s):  
Sex Differences ◽  
Lower Limb ◽  
Test Performance ◽  
Isometric Strength ◽  
Inspiratory Pressure ◽  
Maximal Inspiratory Pressure ◽  
Male Athletes ◽  
Squat Jump ◽  
Respiratory Parameters ◽  
Lower Limb Strength

The study was aimed at comparing lower-limb strength and respiratory parameters between male and female athletes and their interaction with performance in a 107 km mountain ultramarathon. Forty seven runners (29 males and 18 females; mean ± SD age: 41 ± 5 years) were enrolled. Lower-limb strength assessment comprised a squat jump test, an ankle rebound test, and an isometric strength test. Respiratory assessment included pulmonary function testing and the measurement of maximal inspiratory pressure. Male athletes performed largely better in the squat jump (26 ± 4 vs. 21 ± 3 cm; p < 0.001; d = 1.48), while no sex differences were found in the other two lower-limb tests. Concerning the respiratory parameters, male athletes showed largely greater values in pulmonary expiratory variables: forced vital capacity (5.19 ± 0.68 vs. 3.65 ± 0.52 L; p < 0.001; d = 2.53), forced expiratory volume in 1 s (4.24 ± 0.54 vs. 2.97 ± 0.39 L; p < 0.001; d = 2.69), peak expiratory flow (9.9 ± 1.56 vs. 5.89 ± 1.39 L/min; p < 0.001; d = 2.77) and maximum voluntary ventilation in 12 s (171 ± 39 vs. 108 ± 23 L/min; p < 0.001; d = 1.93); while no sex differences were identified in maximal inspiratory pressure. Race time was associated with ankle rebound test performance (r = −0.390; p = 0.027), isometric strength test performance (r = −0.349; p = 0.049) and maximal inspiratory pressure (r = −0.544; p < 0.001). Consequently, it seems that athletes competing in mountain ultramarathons may benefit from improving lower-limb isometric strength, ankle reactive strength and inspiratory muscle strength. Nevertheless, further interventional studies are required to confirm these exploratory results. In addition, the fact that the magnitude of the sex difference for isometric strength was minor, as compared with the other strength tests, could represent one of the factors explaining why the performance gap between males and females is reduced in ultramarathons.

Short-Term Effects of Kinesio Taping on Muscle Recruitment Order During a Vertical Jump: A Pilot Study

2018 ◽  
Vol 27 (4) ◽  
pp. 319-326 ◽  
Author(s):  
Guillermo Mendez-Rebolledo ◽  
Rodrigo Ramirez-Campillo ◽  
Eduardo Guzman-Muñoz ◽  
Valeska Gatica-Rojas ◽  
Alexis Dabanch-Santis ◽  
...  
Keyword(s):  
Ground Reaction Force ◽  
Lower Limb ◽  
Vertical Jump ◽  
Reaction Force ◽  
Countermovement Jump ◽  
Short Term ◽  
Male Athletes ◽  
Squat Jump ◽  
Kinesio Taping ◽  
Recruitment Order

Context: Kinesio taping is commonly used in sports and rehabilitation settings with the aim of prevention and treatment of musculoskeletal injuries. However, limited evidence exists regarding the effects of 24 and 72 hours of kinesio taping on trunk and lower limb neuromuscular and kinetic performance during a vertical jump. Objective: The purpose of this study was to analyze the short-term effects of kinesio taping on height and ground reaction force during a vertical jump, in addition to trunk and lower limb muscle latency and recruitment order. Design: Single-group pretest–posttest. Setting: University laboratory. Participants: Twelve male athletes from different sports (track and field, basketball, and soccer). Interventions: They completed a single squat and countermovement jump at basal time (no kinesio taping), 24, and 72 hours of kinesio taping application on the gluteus maximus, biceps femoris, rectus femoris, gastrocnemius medialis, and longissimus. Main Outcome Measures: Muscle onset latencies were assessed by electromyography during a squat and countermovement jump, in addition to measurements of the jump height and normalized ground reaction force. Results: The kinesio taping had no effect after 24 hours on either the countermovement or squat jump. However, at 72 hours, the kinesio taping increased the jump height (P = .02; d = 0.36) and normalized ground reaction force (P = .001; d = 0.45) during the countermovement jump. In addition, 72-hour kinesio taping reduced longissimus onset latency (P = .03; d = 1.34) and improved muscle recruitment order during a countermovement jump. Conclusions: These findings suggest that kinesio taping may improve neuromuscular and kinetic performance during a countermovement jump only after 72 hours of application on healthy and uninjured male athletes. However, no changes were observed on a squat jump. Future studies should incorporate a control group to verify kinesio taping’s effects and its influence on injured athletes.

How Fast Is a Horizontal Squat Jump?

2018 ◽  
Vol 13 (7) ◽  
pp. 910-916 ◽  
Author(s):  
Pierre Samozino ◽  
Jean Romain Rivière ◽  
Jérémy Rossi ◽  
Jean-Benoit Morin ◽  
Pedro Jimenez-Reyes
Keyword(s):  
Lower Limb ◽  
Rubber Band ◽  
Neuromuscular System ◽  
Healthy Male ◽  
Movement Velocity ◽  
Male Athletes ◽  
Vertical Movements ◽  
Squat Jump ◽  
Squat Jumps ◽  
Very High

Velocity strength training requires exercise modalities that allow athletes to reach very high movement velocity, which is limited during vertical movements involving body weight. Purpose: To quantify the mechanical outputs developed during horizontal squat jumps (HSJs), notably the movement velocity, in comparison with vertical squat jumps (SJs) with and without loads. Methods: Thirteen healthy male athletes performed SJs without additional loads (SJ0) and with a load of ∼60% of body mass (SJ60), and during HSJs performed lying on a roller device with (assisted HSJ [AHSJ]) and without (HSJ) rubber-band assistance. Instantaneous lower-limb extension velocity, force, and power output were measured and averaged over the push-off phase. Results: The force was significantly higher during SJ60 than during SJ0, which was higher than during HSJ and AHSJ. Extension velocity was significantly different across all conditions, with 0.86 (0.07), 1.29 (0.10), 1.59 (0.19), and 1.83 (0.19) m·s−1 for SJ60, SJ0, HSJ, and AHSJ conditions, respectively. Differences in force and velocity values between SJ0 and the other conditions were large to extremely large. Differences were observed in power values only between SJ60 and SJ0, SJ60 and AHSJ, and SJ0 and HSJ. Conclusions: HSJ modalities allow athletes to reach very to extremely largely greater lower-limb extension velocities (HSJ +24.0% [16%], AHSJ +42.8% [17.4%]) compared to those achieved during SJ0. HSJ and AHSJ modalities are inexpensive and practical modalities to train limb-extension velocity capabilities, that is, the ability of the neuromuscular system to produce force at high contraction velocities.

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 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.

IQ Constancy in Disadvantaged Negro Children

1971 ◽  
Vol 29 (1) ◽  
pp. 319-326 ◽  
Author(s):  
Norman A. Milgram
Keyword(s):  
Sex Differences ◽  
Multiple Regression ◽  
Test Performance ◽  
Test Taking ◽  
Comparison Test ◽  
Initial Comparison ◽  
Age Trends ◽  
Iq Scores ◽  
Formal Test

A longitudinal followup of 59 disadvantaged Negro children from age 3 to 8 indicated that: (1) their mean Binet IQ was relatively stable, while their Peabody IQ rose appreciably; (2) the magnitude of the correlation between earlier and later IQ scores was a function of the interval between test-retest and the age of the child on the initial comparison test; (3) ratings on test-taking behavior yielded significant sex differences and age trends; (4) ratings specific to formal test performance were significantly correlated with IQ scores of tests taken concurrent to the ratings and of tests taken one or more years later; (5) these ratings did not, however, enhance in multiple regression the correlation which obtained for predictor and criterion IQ scores alone. Findings were discussed in relation to other studies.

Maximal Inspiratory Pressure in Respiratory Failure

CHEST Journal ◽  
1990 ◽  
Vol 97 (3) ◽  
pp. 97S ◽  
Author(s):  
T.K. Aldrich ◽  
D.J. Prezant ◽  
J.P. Karpel ◽  
A.S. Multz ◽  
J.M. Hendlen
Keyword(s):  
Respiratory Failure ◽  
Inspiratory Pressure ◽  
Maximal Inspiratory Pressure

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.

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