Displaying publications 21 - 40 of 92 in total

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  1. Deng N, Soh KG, Abdullah B, Huang D, Xiao W, Liu H
    PLoS One, 2023;18(7):e0288340.
    PMID: 37459333 DOI: 10.1371/journal.pone.0288340
    BACKGROUND: The literature has proven that plyometric training (PT) improves various physical performance outcomes in sports. Even though PT is one of the most often employed strength training methods, a thorough analysis of PT and how it affects technical skill performance in sports needs to be improved.

    METHODS: This study aimed to compile and synthesize the existing studies on the effects of PT on healthy athletes' technical skill performance. A comprehensive search of SCOPUS, PubMed, Web of Science Core Collection, and SPORTDiscus databases was performed on 3rd May 2023. PICOS was employed to establish the inclusion criteria: 1) healthy athletes; 2) a PT program; 3) compared a plyometric intervention to an active control group; 4) tested at least one measure of athletes' technical skill performance; and 5) randomized control designs. The methodological quality of each individual study was evaluated using the PEDro scale. The random-effects model was used to compute the meta-analyses. Subgroup analyses were performed (participant age, gender, PT length, session duration, frequency, and number of sessions). Certainty or confidence in the body of evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE).

    RESULTS: Thirty-two moderate-high-quality studies involving 1078 athletes aged 10-40 years met the inclusion criteria. The PT intervention lasted for 4 to 16 weeks, with one to three exercise sessions per week. Small-to-moderate effect sizes were found for performance of throwing velocity (i.e., handball, baseball, water polo) (ES = 0.78; p < 0.001), kicking velocity and distance (i.e., soccer) (ES = 0.37-0.44; all p < 0.005), and speed dribbling (i.e., handball, basketball, soccer) (ES = 0.85; p = 0.014), while no significant effects on stride rate (i.e., running) were noted (ES = 0.32; p = 0.137). Sub-analyses of moderator factors included 16 data sets. Only training length significantly modulated PT effects on throwing velocity (> 7 weeks, ES = 1.05; ≤ 7 weeks, ES = 0.29; p = 0.011). The level of certainty of the evidence for the meta-analyzed outcomes ranged from low to moderate.

    CONCLUSION: Our findings have shown that PT can be effective in enhancing technical skills measures in youth and adult athletes. Sub-group analyses suggest that PT longer (> 7 weeks) lengths appear to be more effective for improving throwing velocity. However, to fully determine the effectiveness of PT in improving sport-specific technical skill outcomes and ultimately enhancing competition performance, further high-quality research covering a wider range of sports is required.

    Matched MeSH terms: Muscle Strength
  2. Sadeghi H, Jehu DA, Daneshjoo A, Shakoor E, Razeghi M, Amani A, et al.
    Sports Health, 2021;13(6):606-612.
    PMID: 33583253 DOI: 10.1177/1941738120986803
    BACKGROUND: Poor muscle strength, balance, and functional mobility have predicted falls in older adults. Fall prevention guidelines recommend highly challenging balance training modes to decrease falls; however, it is unclear whether certain modes are more effective. The purpose of this study was to determine whether traditional balance training (BT), virtual reality balance training (VR), or combined exercise (MIX) relative to a waitlist control group (CON) would provoke greater improvements in strength, balance, and functional mobility as falls risk factor proxies for falls in older men.

    HYPOTHESIS: We hypothesized that 8 weeks of MIX will provoke the greatest improvements in falls risk factors, followed by similar improvements after BT and VR, relative to the CON.

    STUDY DESIGN: Single-blinded randomized controlled trial NCT02778841 (ClinicalTrials.gov identifier).

    LEVEL OF EVIDENCE: Level 2.

    METHODS: In total, 64 community-dwelling older men (age 71.8 ± 6.09 years) were randomly assigned into BT, VR, MIX, and CON groups and tested at baseline and at the 8-week follow-up. The training groups exercised for 40 minutes, 3 times per week, for 8 weeks. Isokinetic quadriceps and hamstrings strength on the dominant and nondominant legs were primary outcomes measured by the Biodex Isokinetic Dynamometer. Secondary outcomes included 1-legged stance on firm and foam surfaces, tandem stance, the timed-up-and-go, and gait speed. Separate one-way analyses of covariance between groups were conducted for each outcome using baseline scores as covariates.

    RESULTS: (1) MIX elicited greater improvements in strength, balance, and functional mobility relative to BT, VR, and CON; (2) VR exhibited better balance and functional mobility relative to BT and CON; and (3) BT demonstrated better balance and functional mobility relative to CON.

    CONCLUSION: The moderate to large effect sizes in strength and large effect sizes for balance and functional mobility underline that MIX is an effective method to improve falls risk among older adults.

    CLINICAL RELEVANCE: This study forms the basis for a larger trial powered for falls.

    Matched MeSH terms: Muscle Strength
  3. Ng AK, Hairi NN, Dahlui M, Su TT, Jalaludin MY, Abdul Majid H
    Br J Nutr, 2020 12 14;124(11):1207-1218.
    PMID: 32624008 DOI: 10.1017/S0007114520002202
    The longitudinal relationship between muscle strength, dietary intake and physical activity among adolescents is not well understood. We investigated the trend and longitudinal effects of dietary intakes and physical activity scores on muscle strength in adolescents. This prospective cohort study consisted of 436 adolescents (134 males; 302 females) aged 13 years at baseline (2012) who were followed up at the ages of 15 (2014) and 17 (2016) years, respectively. We measured muscle strength using a calibrated hand dynamometer, estimated dietary intake with a 7-d dietary history and physical activity scores with a validated physical activity questionnaire for older children. A generalised estimating equation was used to examine the effect of dietary intakes and physical activity on muscle strength changes. The analysis was performed separately by sex. The muscle strength for males and females had increased within the 5-year period. The dietary intakes (energy and macronutrients) also increased initially but plateaued after the age of 15 years for both sexes. Females recorded a significant declining trend in physical activity scores compared with males as they grew older. A significant positive longitudinal relationship was found between protein (β = 0·035; P = 0·016), carbohydrate intake (β = 0·002; P = 0·013) and muscle strength among males. However, no longitudinal relationship was found between dietary intake, physical activity and muscle strength among females. Higher protein and carbohydrate intake among males was associated with higher muscle strength but was not observed in females. Nutrition and physical activity focusing on strength building are required in early adolescence and need to be tailored to males and females accordingly.
    Matched MeSH terms: Muscle Strength/physiology*; Muscle Strength Dynamometer
  4. Saeedi P, Black KE, Haszard JJ, Skeaff S, Stoner L, Davidson B, et al.
    Nutrients, 2018 Jul 10;10(7).
    PMID: 29996543 DOI: 10.3390/nu10070887
    Research shows that cardiorespiratory (CRF) and muscular fitness in childhood are associated with a healthier cardiovascular profile in adulthood. Identifying factors associated with measures of fitness in childhood could allow for strategies to optimize cardiovascular health throughout the lifecourse. The aim of this study was to examine the association between dietary patterns and both CRF and muscular fitness in 9⁻11-year-olds. In this study of 398 children, CRF and muscular fitness were assessed using a 20-m shuttle run test and digital hand dynamometer, respectively. Dietary patterns were derived using principal component analysis. Mixed effects linear regression models were used to assess associations between dietary patterns and CRF and muscular fitness. Most children had healthy CRF (99%, FITNESSGRAM) and mean ± SD muscular fitness was 15.2 ± 3.3 kg. Two dietary patterns were identified; “Snacks” and “Fruit and Vegetables”. There were no significant associations between either of the dietary patterns and CRF. Statistically significant but not clinically meaningful associations were seen between dietary patterns and muscular fitness. In an almost exclusively fit cohort, food choice is not meaningfully related to measures of fitness. Further research to investigate diet-fitness relationships in children with lower fitness levels can identify key populations for potential investments in health-promoting behaviors.
    Matched MeSH terms: Muscle Strength*; Muscle Strength Dynamometer
  5. Atikah C, Nihayah M, Omar B, Leonard J, Noor Ibrahim M, Zurkarnain M, et al.
    Sains Malaysiana, 2015;44:1461-1466.
    Fire fighting is one of the most strenuous activities in the hazardous fire service industry. Firefighters have to be physically fit in order to provide an effective and safe fire prevention to the afflicted community and as well as to themselves. The aimed of this cross-sectional study was to evaluate the physical fitness among Malaysian firefighters. The hand grip test to evaluate hand and muscular strength was measured using hand dynamometer and one-minute sit ups and one-minute push ups were conducted to measure abdominal muscle endurance. The sit and reach test was carried out to measure lower back and hamstring flexibility. VO2 max was assessed by a 20 meter shuttle run test to measure cardiorespiratory fitness. A total of 385 subjects were participated and the results showed that 77.1% (n=297) and 84.8% (n=325) of them had very poor scores for hand grip strength and VO2 max, respectively. For one-minute sit ups, 40.8% (n=157) of subjects scored excellent. Meanwhile, 32.7% (n=126) subjects scored average for one-minute push ups. For flexibility test, 53.2% (n=205) subjects had poor flexibilty. The results showed there were significantly difference between one-minute sit ups (p<0.001), one-minute push ups (p<0.05), flexibility (p<0.05) and VO2 max (p<0.001) according to age. As a conclusion, this study provides representative data on physical fitness among Malaysian firefighters. These findings suggested the needs to explore the issues behind low physical fitness among Malaysian firefighters and to find ways to improve them.
    Matched MeSH terms: Muscle Strength
  6. Tan TW, Tan HL, Hsu MF, Huang HL, Chung YC
    BMC Womens Health, 2023 Nov 14;23(1):606.
    PMID: 37964288 DOI: 10.1186/s12905-023-02749-7
    BACKGROUND: Sarcopenia is a chronic disease marked by gradual muscle system and functional decline. Prior research indicates its prevalence in those under 60 varies from 8 to 36%. There is limited evidence on the effectiveness of non-pharmacological interventions for sarcopenia prevention in menopausal women aged 40-60. This study examines the influence of such interventions for sarcopenia prevention on these women.

    METHODS: PubMed, EMBASE, Medline, Cochrane Library, CINAHL, PEDro, and Airiti Library were searched from inception until May 5, 2023. Randomized controlled trials that examined exercise, vitamin D and protein supplementation effects on muscle mass, strength, and physical function. Quality assessment used the Cochrane risk of bias tool, and analysis employed Comprehensive Meta-Analysis version 2.0.

    RESULTS: A total of 27 randomized controlled trials, involving 1,989 participants were identified. Meta-analysis results showed exercise improved lean body mass (SMD = 0.232, 95% CI: 0.097, 0.366), handgrip strength (SMD = 0.901, 95% CI: 0.362, 1.441), knee extension strength (SMD = 0.698, 95% CI: 0.384, 1.013). Resistance training had a small effect on lean body mass, longer exercise duration (> 12 weeks) and higher frequency (60-90 min, 3 sessions/week) showed small to moderate effects on lean body mass. Vitamin D supplementation improved handgrip strength (SMD = 0.303, 95% CI: 0.130, 0.476), but not knee extension strength. There was insufficient data to assess the impact of protein supplementation on muscle strength.

    CONCLUSIONS: Exercise effectively improves muscle mass, and strength in menopausal women. Resistance training with 3 sessions per week, lasting 20-90 min for at least 6 weeks, is most effective. Vitamin D supplementation enhances small muscle group strength. Further trials are needed to assess the effects of vitamin D and protein supplementation on sarcopenia prevention.

    REGISTRATION NUMBER: This review was registered on PROSPERO CRD42022329273.

    Matched MeSH terms: Muscle Strength
  7. Sokran SN, Mohan V, Kamaruddin K, Sulaiman MD, Awang Y, Othman IR, et al.
    Iran J Med Sci, 2015 Jul;40(4):335-40.
    PMID: 26170520
    Hand grip strength (HGS) is a reliable indicator of peripheral muscle strength. Although, numerous studies have investigated the strength of hand grip; little attention has been given to coronary artery disease (CAD) patients, exploring the relationship between HGS and myocardial oxygen consumption (MVO2) index. The current study aimed to evaluate the interaction between HGS and MVO2 index findings before and after cardiac surgery.
    Matched MeSH terms: Muscle Strength
  8. Khuna L, Mato L, Amatachaya P, Thaweewannakij T, Amatachaya S
    Malays J Med Sci, 2019 Jan;26(1):99-106.
    PMID: 30914897 DOI: 10.21315/mjms2019.26.1.9
    Background: Decreased rehabilitation time may increase the need for walking devices at the time of discharge to promote levels of independence among ambulatory individuals with spinal cord injury (SCI). However, using walking devices could create adverse effects on patients. This study explores the proportion of walking devices used, potential for walking progression, and associated factors among ambulatory individuals with SCI.

    Methods: Fifty-seven participants were assessed for their demographics and functional ability relating to the requirement for walking devices, including the Timed Up and Go Test (TUGT) and lower limb loading during sit-to-stand (LLL-STS).

    Results: Thirty-five participants (61%) used a walking device, particularly a standard walker, for daily walking. More than half of them (n = 23, 66%) had potential of walking progression (i.e., safely walk with a less-support device than the usual one). The ability of walking progression was significantly associated with a mild severity of injury, increased lower-limb muscle strength, decreased time to complete the TUGT, and, in particular, increased LLL-STS.

    Conclusion: A large proportion of ambulatory individuals with SCI have the potential for walking progression, which may increase their level of independence and minimise the appearance of disability. Strategies to promote LLL-STS are important for this progression.

    Matched MeSH terms: Muscle Strength
  9. Ibitoye MO, Estigoni EH, Hamzaid NA, Wahab AK, Davis GM
    Sensors (Basel), 2014;14(7):12598-622.
    PMID: 25025551 DOI: 10.3390/s140712598
    The evoked electromyographic signal (eEMG) potential is the standard index used to monitor both electrical changes within the motor unit during muscular activity and the electrical patterns during evoked contraction. However, technical and physiological limitations often preclude the acquisition and analysis of the signal especially during functional electrical stimulation (FES)-evoked contractions. Hence, an accurate quantification of the relationship between the eEMG potential and FES-evoked muscle response remains elusive and continues to attract the attention of researchers due to its potential application in the fields of biomechanics, muscle physiology, and rehabilitation science. We conducted a systematic review to examine the effectiveness of eEMG potentials to assess muscle force and fatigue, particularly as a biofeedback descriptor of FES-evoked contractions in individuals with spinal cord injury. At the outset, 2867 citations were identified and, finally, fifty-nine trials met the inclusion criteria. Four hypotheses were proposed and evaluated to inform this review. The results showed that eEMG is effective at quantifying muscle force and fatigue during isometric contraction, but may not be effective during dynamic contractions including cycling and stepping. Positive correlation of up to r = 0.90 (p < 0.05) between the decline in the peak-to-peak amplitude of the eEMG and the decline in the force output during fatiguing isometric contractions has been reported. In the available prediction models, the performance index of the eEMG signal to estimate the generated muscle force ranged from 3.8% to 34% for 18 s to 70 s ahead of the actual muscle force generation. The strength and inherent limitations of the eEMG signal to assess muscle force and fatigue were evident from our findings with implications in clinical management of spinal cord injury (SCI) population.
    Matched MeSH terms: Muscle Strength*
  10. Benford K, Swami V
    Body Image, 2014 Sep;11(4):454-7.
    PMID: 25113287 DOI: 10.1016/j.bodyim.2014.07.004
    The present study examined associations between the Big Five personality domains and measures of men's body image. A total of 509 men from the community in London, UK, completed measures of drive for muscularity, body appreciation, the Big Five domains, and subjective social status, and provided their demographic details. The results of a hierarchical regression showed that, once the effects of participant body mass index (BMI) and subjective social status had been accounted for, men's drive for muscularity was significantly predicted by Neuroticism (β=.29). In addition, taking into account the effects of BMI and subjective social status, men's body appreciation was significantly predicted by Neuroticism (β=-.35) and Extraversion (β=.12). These findings highlight potential avenues for the development of intervention approaches based on the relationship between the Big Five personality traits and body image.
    Matched MeSH terms: Muscle Strength*
  11. Islam MA, Sundaraj K, Ahmad RB, Sundaraj S, Ahamed NU, Ali MA
    PLoS One, 2014;9(5):e96628.
    PMID: 24802858 DOI: 10.1371/journal.pone.0096628
    This study aimed: i) to examine the relationship between the magnitude of cross-talk in mechanomyographic (MMG) signals generated by the extensor digitorum (ED), extensor carpi ulnaris (ECU), and flexor carpi ulnaris (FCU) muscles with the sub-maximal to maximal isometric grip force, and with the anthropometric parameters of the forearm, and ii) to quantify the distribution of the cross-talk in the MMG signal to determine if it appears due to the signal component of intramuscular pressure waves produced by the muscle fibers geometrical changes or due to the limb tremor.
    Matched MeSH terms: Muscle Strength/physiology*
  12. Chin KY, Soelaiman IN, Naina Mohamed I, Shahar S, Teng NI, Suhana Mohd Ramli E, et al.
    Aging Male, 2012 Dec;15(4):240-5.
    PMID: 23098182 DOI: 10.3109/13685538.2012.724740
    OBJECTIVE: Variations in testosterone levels are associated with several outcomes of aging. The present study aimed to examine the relationship between age-related decline of testosterone levels and changes in bone health status, handgrip strength, body fat percentage and fat-free mass.
    MATERIALS AND METHODS: A total of 335 Malaysian Chinese and Malay men aged 40 years and above were recruited for this study. Their body compositions, calcaneal speed of sound and handgrip strength were measured and their blood was collected. Linear regression analysis was done to examine the relationship among age, testosterone levels and outcomes of aging.
    RESULTS: The results indicated significant changes in all testosterone measurements, sex hormone binding globulin level, calcaneal speed of sound, handgrip strength, body fat percentage and fat-free mass with age (p < 0.05). Age-dependent decline in bioavailable and free testosterone levels were significantly associated with reduction in calcaneal speed of sound, fat-free mass and handgrip strength (p < 0.05). Age-dependent decline in the total testosterone level was significantly associated with an increase in body fat percentage among the elderly men (p < 0.05).
    CONCLUSION: Testosterone levels are associated with changes in outcome of aging such as bone health status, muscle strength and body composition, and the relationships are age-dependent.
    Matched MeSH terms: Muscle Strength/physiology*
  13. Ajit Singh DK, Bailey M, Lee R
    Muscle Nerve, 2011 Jul;44(1):74-9.
    PMID: 21488056 DOI: 10.1002/mus.21998
    Loss of lumbar extensor muscle strength and fatigue resistance may contribute to functional disability.
    Matched MeSH terms: Muscle Strength/physiology*
  14. Khoo S, Al-Shamli AK
    Asia Pac J Public Health, 2012 Jan;24(1):128-35.
    PMID: 20460285 DOI: 10.1177/1010539510366178
    This study investigated the relationship between leisure-time physical activity and physical fitness (cardiovascular fitness, body fat percentage, flexibility, muscle strength, and endurance) of 10th-grade male students in Oman. Data were collected from 330 students. All participants completed a descriptive questionnaire, a 1 mile walk/run test; a skinfold analysis of the chest, abdomen, and thigh; a sit and reach test; a hand grip test; and a 1-minute sit-up test. Students spent an average of 19.20 ± 6.77 hours on sedentary activities, 3.46 ± 2.11 hours on sports activities, and 11.22 ± 9.24 hours working per week. The students had an average body fat percentage of 6.38% ± 4.67%, muscle strength 38.04 ± 7.55 kg, flexibility 38.01 ± 7.41 cm, abdominal muscle endurance 38.85 ± 8.15 times/min, and cardiovascular endurance 8.10 ± 1.65 minutes.
    Matched MeSH terms: Muscle Strength/physiology
  15. Ooi CH, Tan A, Ahmad A, Kwong KW, Sompong R, Ghazali KA, et al.
    J Sports Sci, 2009 Dec;27(14):1591-9.
    PMID: 19967588 DOI: 10.1080/02640410903352907
    The aims of this study were to establish the physical and physiological attributes of elite and sub-elite Malaysian male badminton players and to determine whether these attributes discriminate elite players from sub-elite players. Measurements and tests of basic anthropometry, explosive power, anaerobic recovery capacity, badminton-specific movement agility, maximum strength, and aerobic capacity were conducted on two occasions, separated by at least one day. The elite (n = 12) and sub-elite (n = 12) players' characteristics were, respectively: mean age 24.6 years (s = 3.7) and 20.5 years (s = 0.7); mass 73.2 kg (s = 7.6) and 62.7 kg (s = 4.2); stature 1.76 m (s = 0.07) and 1.71 m (s = 0.05); body fat 12.5% (s = 4.8) and 9.5% (s = 3.4); estimated VO(2max) 56.9 ml . kg(-1) . min(-1) (s = 3.7) and 59.5 ml . kg(-1) . min(-1) (s = 5.2). The elite players had greater maximum absolute strength in one-repetition maximum bench press (P = 0.015) compared with the sub-elite players. There were significant differences in instantaneous lower body power estimated from vertical jump height between the elite and sub-elite groups (P < 0.01). However, there was no significant difference between groups in shuttle run tests and on-court badminton-specific movement agility tests. Our results show that elite Malaysian male badminton players are taller, heavier, and stronger than their sub-elite counterparts. The test battery, however, did not allow us to discriminate between the elite and sub-elite players, suggesting that at the elite level tactical knowledge, technical skills, and psychological readiness could be of greater importance.
    Matched MeSH terms: Muscle Strength/physiology*
  16. Kamarul T, Ahmad TS, Loh WY
    Med J Malaysia, 2006 Dec;61 Suppl B:37-44.
    PMID: 17600991
    Hand grip strength measurement is a recognized part of hand function assessment. The standard measurement using the Jamar dynamometer and comparing these results to the recommended normal values suggested by the manufacturers of the Jamar was questioned as these values were based on Western population. A study comparing a novel method of predicting grip strength using our software was conducted on 25 normal subjects using the LIDO kinetic workset (Group A and B ). These results were then compared against our predictive software (Group A) and the expected values supplied together with the Jamar Dynamometer (Group B). In another group, 22 normal subjects were tested using the Jamar (Group C and D) and then matched against the predicted values using their recommended chart (Group C). The last group (Group D) was tested using the Jamar but the values attained were compared to the results from our software. In group A, the predictability of our predictive method was 100% (both R & L) as compared to (R = 64%, L = 68%) in group B, (R = 27.3%, L = 59.1%) in group C and (R = 81.8%, L = 86.4%) in group D. The differences between the predictability of both methods were statistically significant. The data collected using both the Jamar and the LIDO kinetic workset correlated well to the data from our software but not to the values suggested by the manufacturers of Jamar. We conclude that our method of predicting hand grip values are superior to that suggested by the manufacturers of dynamometers. The standard reference for hand grip strength provided by the manufacturers is less accurate in predicting the grip strength of our local population.
    Matched MeSH terms: Muscle Strength Dynamometer*
  17. Vijayakumar P, Nagarajan M, Ramli A
    J Back Musculoskelet Rehabil, 2012;25(4):225-30.
    PMID: 23220803 DOI: 10.3233/BMR-2012-0337
    Osteitis pubis among soccer athletes is a disabling painful condition and it is difficult to manage without integrating a multimodal treatment approach. There is limited scientific evidence on the effectiveness of exercise in treating Osteitis pubis especially when it progress to a chronic painful condition. The purpose of this case report is to discuss the successful multimodal physiotherapeutic management for a 15-year old soccer athlete diagnosed with stage-IV Osteitis pubis. Land and water based active core muscle strengthening exercises, Proprioceptive neuromuscular facilitation techniques (PNF) and Manual Therapy are some of the essential components incorporated in multimodal intervention approach with emphasis to water based strength and endurance training exercises. The athlete was able to make progress to a successful recovery from his chronic painful condition and accomplished the clearly established clinical outcomes during each phase of rehabilitation.
    Matched MeSH terms: Muscle Strength/physiology
  18. Khong TK, Selvanayagam V, Yusof A
    Eur J Sport Sci, 2021 Feb;21(2):224-230.
    PMID: 32056510 DOI: 10.1080/17461391.2020.1730980
    Carbohydrate (CHO) mouth rinse has been shown to improve endurance performance and maintain the central drive of contracting muscles. Salt (NaCl) mouth rinse solution, often used in dentistry to desensitise the oral cavity to pain, could also activate cortical areas of the brain. Hence, the objective of this preliminary study was to investigate whether CHO (glucose) and NaCl mouth rinses could attenuate the reduction in maximum voluntary contraction (MVC) and sustained MVC (sMVC) following an endurance exercise (30-minute cycling at 70% VO2max). Ten subjects (male, age: 22 ± 1 years, weight: 65.3 ± 12.4 kg, height: 164.5 ± 7.5 cm, VO2max: 48.3 ± 6.1 mL kg-1 min-1) completed three trials of 30-minute cycling exercise. In a randomised cross-over study, in each trial, the participants rinsed using either water, 6% glucose, or 6% NaCl solution for 5 s immediately prior to and every 10 min during the cycling exercise. The MVC and sMVC were measured pre and post cycling. Analysis of variance showed significant interaction and time effects for MVC, while for sMVC there was a significant interaction with time and group effects. Both MVC and sMVC were higher post cycling in the glucose and NaCl groups compared to the water group, which suggests that activation of glucose and NaCl oral receptors could better preserve post-exercise force production. This is the first study to show that NaCl mouth rinse can produce a comparable effect on glucose. Hence, mouth rinses may be able to activate other distinct pathways that could attenuate fatigue.
    Matched MeSH terms: Muscle Strength/drug effects
  19. Shariat A, Lam ETC, Shaw BS, Shaw I, Kargarfard M, Sangelaji B
    J Back Musculoskelet Rehabil, 2017;30(3):641-647.
    PMID: 28372315 DOI: 10.3233/BMR-160526
    STUDY DESIGN: True experimental design.

    BACKGROUND: The back squat is an integral aspect of any resistance training program to improve athletic performance. It is also used for injury prevention of the lower limbs.

    OBJECTIVE: The purpose of this study was to examine the effect of back squat training at different intensities on strength and flexibility of the hamstring muscle group (HMG).

    METHODS: Twenty-two male recreational bodybuilders with at least two years of experience in resistance training were recruited to participate in a nine-week training program. They were randomly assigned to a heavy back squat group (90-95% of one repetition maximum) or a moderate-intensity back squat group (60-65% of one repetition maximum).

    RESULTS: The heavy back squat group resulted in a significantly (p < 0.001) increased in one repetition maximum strength but a significant (p < 0.001) reduction in HMG flexibility when compared to their counterparts. The results of the study indicate that while a heavy back squat training program is effective in improving strength, it has an adverse effect on the flexibility of the HMG.

    CONCLUSION: The implication of this study is that there is a tradeoff between strength and flexibility and trainers should select the appropriate training protocols for their athletes to maximize athletic performance.

    Matched MeSH terms: Muscle Strength/physiology
  20. Rahman NN, Singh DK, Lee R
    Clin Interv Aging, 2017;12:523-529.
    PMID: 28352165 DOI: 10.2147/CIA.S110329
    Aging is associated with alterations in thoracolumbar curvatures and respiratory function. Research information regarding the correlation between thoracolumbar curvatures and a comprehensive examination of respiratory function parameters in older adults is limited. The aim of the present study was to examine the correlation between thoracolumbar curvatures and respiratory function in community-dwelling older adults. Thoracolumbar curvatures (thoracic and lumbar) were measured using a motion tracker. Respiratory function parameters such as lung function, respiratory rate, respiratory muscle strength and respiratory muscle thickness (diaphragm and intercostal) were measured using a spirometer, triaxial accelerometer, respiratory pressure meter and ultrasound imaging, respectively. Sixty-eight community-dwelling older males and females from Kuala Lumpur, Malaysia, with mean (standard deviation) age of 66.63 (5.16) years participated in this cross-sectional study. The results showed that mean (standard deviation) thoracic curvature angle and lumbar curvature angles were -46.30° (14.66°) and 14.10° (10.58°), respectively. There was a significant negative correlation between thoracic curvature angle and lung function (forced expiratory volume in 1 second: r=-0.23, P<0.05; forced vital capacity: r=-0.32, P<0.05), quiet expiration intercostal thickness (r=-0.22, P<0.05) and deep expiration diaphragm muscle thickness (r=-0.21, P<0.05). The lumbar curvature angle had a significant negative correlation with respiratory muscle strength (r=-0.29, P<0.05) and diaphragm muscle thickness at deep inspiration (r=-0.22, P<0.05). However, respiratory rate was correlated neither with thoracic nor with lumbar curvatures. The findings of this study suggest that increase in both thoracic and lumbar curvatures is correlated with decrease in respiratory muscle strength, respiratory muscle thickness and some parameters of lung function. Clinically, both thoracic and lumbar curvatures, respiratory muscles and lung function should be taken into consideration in the holistic management of respiratory function among older adults.
    Matched MeSH terms: Muscle Strength/physiology
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