Log-linear Adjusted Lower Limb Muscle Power of Boys and Girls

LANGUAGE NOTE | Document text in English; abstract also in Chinese.The study investigated the log-linear muscle power of the lower limbs in a group of 13 to 14 year old boys and girls. Participants were 48 boys (stature: 1.69±0.05m; body mass: 57.9±11.8kg; lower limb muscle mass: 16.4±2.5kg) and 38 girls (stature: 1.59±0.06m; body mass: 57.7±7.6kg; lower limb muscle mass: 12.5±1.2kg). Lower limb muscle mass (LLMM) was determined using a dual energy X-ray absorptiometric (DEXA) procedure. Participants completed a 30s Wingate Anaerobic Test (WAnT) where peak power (PP) and mean power (MP) were expressed in relation to LLMM using log-linear adjustment procedures. Boys and girls had similar log-linear adjusted PP (495W vs. 488W, p>0.05) and MP (423W vs. 422W, p>0.05) when they were expressed in relation to LLMM. However, common b exponents that defined the allometric relationship between PP and MP, and LLMM in both boys and girls were 1.26 (SE 0.15), and 1.21 (SE 0.15), respectively. These were markedly different from the b exponent of 1.0 used in the ratio standard, or the 0.67 value predicted from geometric similarity theory. Despite a similar interpretation of data (i.e. no sex difference in lower limb muscle power in boys and girls) using either allometric modeling, allometric modeling of sample-specific exercise data is recommended to produce an appropriate size-independent variable, to allow appropriate comparisons in performance between boys and girls.本文以對數一線性修正法對13 — 14歲少年下肢力量進行了研究。測試對象為48名男孩(身高為1.69 ± 0.05米，體重為57.9 ± 11.8公斤，下肢去脂體重為16.4 ±2.5公斤）和38名女孩(身高為1.59 ± 0.06米，體重為57.7 ± 7.6公斤，下肢去脂體重為12.5 ± 1.2公斤）。以雙光能X光吸收儀(DEXA)測定受試者下肢的去脂體重。受試對象在自行車功率儀上完成30秒溫蓋特無氧功率測試 (Wingate Anaerobic Test, WAnT)，以對數-線性修正法表示最高功率和平均功率與下肢去脂體重的關係。其結果顯不，男孩與女孩的最高功率分別為495瓦與488瓦(p>0.05)，平均功率分別為423瓦與422瓦(p>0.05)。根據對數-線性修正法所得的最高功率和平均功率與下肢去脂體重關係的b指數分別1.26 (SE為0.15)與1.21 (SE為0.15)，男女相同。此結果與常用標準比b指數為1，或應用幾何相似理論推測值0.67等方法所得的結果明顯不同。應用異速生長模型(對數-線性修正法)可測得與其實驗對象和運動形式相適應的形態機體指標，因而可較正確地比較少年男女之間的運動能力。

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Repeated Sprint Performances among Girls and Women

Asian Journal of Physical Education & Recreation ◽

10.24112/ajper.71254 ◽

2001 ◽

Vol 7 (1) ◽

pp. 55-60

Author(s):

Michael CHIA

Keyword(s):

Muscle Mass ◽

Lower Limb ◽

Lower Limb Muscle ◽

Limb Muscle ◽

Active Recovery ◽

Wingate Anaerobic Test ◽

Warm Up ◽

Recovery Interval ◽

The Third ◽

Anaerobic Test

LANGUAGE NOTE | Document text in English; abstract also in Chinese.The aim of the study was to compare between girls and women, the recovery of Wingate Anaerobic Test (WAnT) power after two prior sprints of 15-seconds' duration with a short active recovery interval in-between the sprints. Participants with written informed consent were 19 girls (age: 13.6±1.0yrs; body mass: 51.2±7.6kg & stature: 1.59±0.06m) and 21 women (age: 25.1±2.7yrs; body mass: 57.9±7.7kg & stature: 1.61±0.05m). Lower limb muscle mass was determined using a Dual-energy X-ray Absorptiometric (DXA) procedure. Following a standardized warm-up, each participant completed a series of three 15-second WAnTs, with each test separated by a 45-second active recovery interval. WAnT power variables were computed over 1-second time periods and were corrected for the inertia of the cycle ergometer (Monark 834E). Whole blood lactate concentrations (BL) were obtained immediately post warm-up and at three minutes after the completion of the third WAnT. Peak power (PP), expressed in watts per lower limb muscle mass (W. kg -1LLMM) were significantly greater in women than in girls in the first 15s WAnT (46.1±10.9 vs 37.4±2.3W.kg -1LLMM, p0.05). Girls were better able to replicate their power achieved in the first WAnT, in the third WAnT than women (mean of the differences ± standard deviation of the differences for PP: 84±47W vs 174±84W; MP: 81±45W vs 161+65W, p0.05), and at three minutes post exercise (9.2±1.2 vs. 8.4±1.3 mM.L-1, p >0.05) were not significantly different in girls and women.本文以溫蓋特無氧功率試驗(Wingate Anaerobic Test, WAnT)為研究方法，重複測定了少女和婦女15秒的無氧功率，旨在比較少女與婦女之間的無氧能力極其恢復。受試對象為19名少女(年齡：13.6±1.0歲；體重：51.2±7.6公斤；身高：1.59±0.06米）和21名婦女（年齡:25.1±2.7歲；體重：57.9±7.7公斤；身高：1.61±0.05米）。以雙光能X光吸收儀(DXA)測定受試者下肢的瘦體重。在標準化的準備活動之後，受試者在自行車測功儀(Monark 834E)上完成3次15秒最快速度的踏車運動，各次運動之間以45秒的活動性休息為間隔。在準備活動後即刻和第三次運動試驗后3分鐘采血測定血乳酸濃度。在首次15秒WAnT測試中，婦女組的最高功率(46.1±10.9瓦．公斤下肢瘦體重-1)明顯高于少女組(37.4±2.3瓦．公升-1肢瘦體重-1，p0.05)。第三次15秒運動試驗中，少女組的無氧功率明顯地較婦女組接近第一次WAnT測試中所達到的功率(p0.05)，分別為2.5±0.5毫克分子．升-1與1.9±0.5毫克分子．升-1及9.2±1.2毫克分子．升-1與8.4±1.3毫克分子．升-1。

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Short-Term Effects of Rolling Massage on Energy Cost of Running and Power of the Lower Limbs

International Journal of Sports Physiology and Performance ◽

10.1123/ijspp.2018-0142 ◽

2018 ◽

Vol 13 (10) ◽

pp. 1337-1343 ◽

Cited By ~ 4

Author(s):

Nicola Giovanelli ◽

Filippo Vaccari ◽

Mirco Floreani ◽

Enrico Rejc ◽

Jasmine Copetti ◽

...

Keyword(s):

Lower Limb ◽

Muscle Power ◽

Statistical Significance ◽

Lower Limbs ◽

Lower Limb Muscle ◽

Limb Muscle ◽

Maximal Power ◽

Endurance Running ◽

Running Performance ◽

And Control

Purpose: Self-myofascial release (SMFR) is a type of self-massage that is becoming popular among athletes. However, SMFR’s effects on running performance have not yet been investigated. The aim of this study was to evaluate the effects of SMFR on the cost of running (Cr). In addition, the authors evaluated the effects of SMFR on lower-limb muscle power. Methods: Cr and lower-limb muscle power during squat jump (SJ) and countermovement jump (CMJ) were measured before (PRE), immediately after (POST), and 3 h after (POST 3h) an SMFR protocol (experimental condition). In the control-condition testing session, the same measurements were performed without undergoing the SMFR protocol. Experimental and control conditions were tested in a randomized order. Results: Cr at POST trended to increase compared with PRE (+6.2% [8.3%], P = .052), whereas at POST 3h, Cr was restored to PRE values (+0.28% [9.5%], P = .950). In the experimental condition, no significant effect of time was observed for maximal power exerted during SJ. By contrast, maximal power exerted during CMJ at POST and at POST 3h was significantly higher than that observed at PRE (+7.9% [6.3%], P = .002 and +10.0% [8.7%], P = .004, respectively). The rate of force development measured during CMJ also increased after SMFR, reaching statistical significance at 200 ms from force onset at POST 3h (+38.9%, P = .024). Conclusions: An acute use of foam rollers for SMFR performed immediately prior to running may negatively affect endurance running performance, but its use should be added before explosive motor performances that include stretch-shortening cycles.

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Effects of Dominant and Nondominant Limb Immobilization on Muscle Activation and Physical Demand during Ambulation with Axillary Crutches

Journal of Functional Morphology and Kinesiology ◽

10.3390/jfmk6010016 ◽

2021 ◽

Vol 6 (1) ◽

pp. 16

Author(s):

Kara B. Bellenfant ◽

Gracie L. Robbins ◽

Rebecca R. Rogers ◽

Thomas J. Kopec ◽

Christopher G. Ballmann

Keyword(s):

Lower Limb ◽

Muscle Activation ◽

Weight Bearing ◽

Lower Limbs ◽

Medial Gastrocnemius ◽

Bipedal Walking ◽

Lower Limb Muscle ◽

Limb Muscle ◽

Physical Demand ◽

Limb Dominance

The purpose of this study was to investigate the effects of how limb dominance and joint immobilization alter markers of physical demand and muscle activation during ambulation with axillary crutches. In a crossover, counterbalanced study design, physically active females completed ambulation trials with three conditions: (1) bipedal walking (BW), (2) axillary crutch ambulation with their dominant limb (DOM), and (3) axillary crutch ambulation with their nondominant limb (NDOM). During the axillary crutch ambulation conditions, the non-weight-bearing knee joint was immobilized at a 30-degree flexion angle with a postoperative knee stabilizer. For each trial/condition, participants ambulated at 0.6, 0.8, and 1.0 mph for five minutes at each speed. Heart rate (HR) and rate of perceived exertion (RPE) were monitored throughout. Surface electromyography (sEMG) was used to record muscle activation of the medial gastrocnemius (MG), soleus (SOL), and tibialis anterior (TA) unilaterally on the weight-bearing limb. Biceps brachii (BB) and triceps brachii (TB) sEMG were measured bilaterally. sEMG signals for each immobilization condition were normalized to corresponding values for BW.HR (p < 0.001) and RPE (p < 0.001) were significantly higher for both the DOM and NDOM conditions compared to BW but no differences existed between the DOM and NDOM conditions (p > 0.05). No differences in lower limb muscle activation were noted for any muscles between the DOM and NDOM conditions (p > 0.05). Regardless of condition, BB activation ipsilateral to the ambulating limb was significantly lower during 0.6 mph (p = 0.005) and 0.8 mph (p = 0.016) compared to the same speeds for BB on the contralateral side. Contralateral TB activation was significantly higher during 0.6 mph compared to 0.8 mph (p = 0.009) and 1.0 mph (p = 0.029) irrespective of condition. In conclusion, limb dominance appears to not alter lower limb muscle activation and walking intensity while using axillary crutches. However, upper limb muscle activation was asymmetrical during axillary crutch use and largely dependent on speed. These results suggest that functional asymmetry may exist in upper limbs but not lower limbs during assistive device supported ambulation.

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Association of lower limb muscle mass and energy expenditure with visceral fat mass in healthy men

Diabetology & Metabolic Syndrome ◽

10.1186/1758-5996-6-27 ◽

2014 ◽

Vol 6 (1) ◽

Cited By ~ 13

Author(s):

Shusuke Yagi ◽

Muneyuki Kadota ◽

Ken-ichi Aihara ◽

Koji Nishikawa ◽

Tomoya Hara ◽

...

Keyword(s):

Energy Expenditure ◽

Muscle Mass ◽

Fat Mass ◽

Visceral Fat ◽

Lower Limb ◽

Lower Limb Muscle ◽

Limb Muscle ◽

Healthy Men

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Modeling the blood lactate kinetics at maximal short-term exercise conditions in children, adolescents, and adults

Journal of Applied Physiology ◽

10.1152/japplphysiol.00062.2005 ◽

2005 ◽

Vol 99 (2) ◽

pp. 499-504 ◽

Cited By ~ 60

Author(s):

Ralph Beneke ◽

Matthias Hütler ◽

Marcus Jung ◽

Renate M. Leithäuser

Keyword(s):

Blood Lactate ◽

Muscle Mass ◽

Body Mass ◽

Short Term ◽

Wingate Anaerobic Test ◽

Blood Compartment ◽

Test Conditions ◽

Age Related ◽

Adolescents And Adults ◽

Anaerobic Test

Whether age-related differences in blood lactate concentrations (BLC) reflect specific BLC kinetics was analyzed in 15 prepubescent boys (age 12.0 ± 0.6 yr, height 1.54 ± 0.06 m, body mass 40.0 ± 5.2 kg), 12 adolescents (16.3 ± 0.7 yr, 1.83 ± 0.07 m, 68.2 ± 7.5 kg), and 12 adults (27.2 ± 4.5 yr, 1.83 ± 0.06 m, 81.6 ± 6.9 kg) by use of a biexponential four-parameter kinetics model under Wingate Anaerobic Test conditions. The model predicts the lactate generated in the extravasal compartment (A), invasion ( k1), and evasion ( k2) of lactate into and out of the blood compartment, the BLC maximum (BLCmax), and corresponding time (TBLCmax). BLCmax and TBLCmax were lower ( P < 0.05) in boys (BLCmax 10.2 ± 1.3 mmol/l, TBLCmax 4.1 ± 0.4 min) than in adolescents (12.7 ± 1.0 mmol/l, 5.5 ± 0.7 min) and adults (13.7 ± 1.4 mmol/l, 5.7 ± 1.1 min). No differences were found in A related to the muscle mass (AMM) and k1 between boys (AMM: 22.8 ± 2.7 mmol/l, k1: 0.865 ± 0.115 min−1), adolescents (22.7 ± 1.3 mmol/l, 0.692 ± 0.221 min−1), and adults (24.7 ± 2.8 mmol/l, 0.687 ± 0.287 min−1). The k2 was higher ( P < 0.01) in boys (2.87 10−2 ± 0.75 10−2 min−1) than in adolescents (2.03 × 10−2 ± 0.89 × 10−2 min−1) and adults (1.99 × 10−2 ± 0.93 × 10−2 min−1). Age-related differences in the BLC kinetics are unlikely to reflect differences in muscular lactate or lactate invasion but partly faster elimination out of the blood compartment.

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