Human skeletal muscle responses vary with age and gender during fatigue due to incremental isometric exercise

2002 ◽  
Vol 93 (5) ◽  
pp. 1813-1823 ◽  
Author(s):  
J. A. Kent-Braun ◽  
A. V. Ng ◽  
J. W. Doyle ◽  
T. F. Towse
Keyword(s):  
Muscle Activation ◽  
Contractile Function ◽  
Compound Muscle Action Potential ◽  
Isometric Exercise ◽  
Age And Gender ◽  
Muscle Action Potential ◽  
Activation Ratio ◽  
Older Subjects ◽  
And Gender ◽  
Ankle Dorsiflexor

The purpose of this study was to compare the magnitude and mechanisms of ankle dorsiflexor muscle fatigue in 20 young (33 ± 6 yr, mean ± SD) and 21 older (75 ± 6 yr) healthy men and women of similar physical activity status. Noninvasive measures of central and peripheral (neuromuscular junction, sarcolemma) muscle activation, muscle contractile function, and intramuscular energy metabolism were made before, during, and after incremental isometric exercise. Older subjects fatigued less than young ( P < 0.01); there was no effect of gender on fatigue ( P = 0.24). For all subjects combined, fatigue was modestly related to preexercise strength ( r = 0.49, P < 0.01). Neither central (central activation ratio) nor peripheral (compound muscle action potential) activation played a significant role in fatigue in any group. During exercise, intracellular concentrations of Piand H2PO[Formula: see text] increased more and pH fell more in young compared with older subjects ( P < 0.01) and in men compared with women ( P < 0.01). These varied metabolic responses to exercise suggest a greater reliance on nonoxidative sources of ATP in young compared with older subjects and in men compared with women. These results suggest that the mechanisms of fatigue vary with age and gender, regardless of whether differences in the magnitude of fatigue are observed.

scholarly journals Influence of age and gender on the profile of exhaled volatile organic compounds analyzed by an electronic nose

2016 ◽  
Vol 42 (2) ◽  
pp. 143-145 ◽  
Author(s):  
Silvano Dragonieri ◽  
Vitaliano Nicola Quaranta ◽  
Pierluigi Carratu ◽  
Teresa Ranieri ◽  
Onofrio Resta
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Electronic Nose ◽  
Principal Component ◽  
Exhaled Breath ◽  
Age And Gender ◽  
Volatile Organic ◽  
Older Subjects ◽  
Never Smokers ◽  
And Gender

We aimed to investigate the effects of age and gender on the profile of exhaled volatile organic compounds. We evaluated 68 healthy adult never-smokers, comparing them by age and by gender. Exhaled breath samples were analyzed by an electronic nose (e-nose), resulting in "breathprints". Principal component analysis and canonical discriminant analysis showed that older subjects (≥ 50 years of age) could not be distinguished from younger subjects on the basis of their breathprints, as well as that the breathprints of males could not distinguished from those of females (cross-validated accuracy, 60.3% and 57.4%, respectively).Therefore, age and gender do not seem to affect the overall profile of exhaled volatile organic compounds measured by an e-nose.

Strength, Size, and Muscle Quality in the Upper Arm following Unilateral Training in Younger and Older Males and Females

2009 ◽  
Vol 2 ◽  
pp. CMAMD.S1180 ◽  
Author(s):  
Leah C. Tanton ◽  
Thomas A. Cappaert ◽  
Paul M. Gordon ◽  
Robert F. Zoeller ◽  
Theodore J. Angelopoulos ◽  
...  
Keyword(s):  
Muscle Quality ◽  
Resonance Imaging ◽  
Age And Gender ◽  
Males And Females ◽  
Older Subjects ◽  
Magnetic Resonance Imaging Mri ◽  
And Gender ◽  
Unilateral Training ◽  
Older Males

Purpose To assess strength, size, and muscle quality differences between younger and older males and females in response to training. Methods The bicep and tricep of the non-dominant arm were trained for twelve weeks in younger and older males and females (n = 41). The bicep of both arms were assessed pre and post for muscle strength using one-repetition maximum (1 RM) testing, and size using magnetic resonance imaging (MRI). Results Strength (p < 0.05), mCSA (p < 0.05), and 1 RM MQ (p < 0.00) increased in response to training in all subjects regardless of age or gender. Younger and older subjects had similar increases in strength (45.49 ± 15.30% vs. 42.67 ± 26.67% respectively), mCSA (16.22 ± 7.98% vs. 19.17 ± 6.19% respectively), and 1RM MQ (25.73 ± 15.76 vs. 19.67 ± 20.66 respectively). Women increased their strength (55.59 ± 19.45% vs. 32.87 ± 15.66% p < 0.00 respectively), size (20.36 ± 6.29% vs. 14.72 ± 7.28% p < 0.02 respectively), and 1 RM MQ (29.74 ± 18.33% vs. 16.30 ± 15.59% p <.02) more than men. In comparing age and gender, younger females increased their strength more than older males (56.42 ± 12.92% vs. 29.17 ± 21.8% p <.02 respectively). Older females also increased their strength more than older males (54.68 ± 25.73 vs. 29.17 ± 21.80% respectively). Younger females increased their 1 RM MQ more than older males (.18 ± .08 kg/cm vs. .06 ± .08 kg/cm p <.02 respectively). Conclusion Strength and mCSA increases similarly in older and younger subjects. However, the overall strength and quality of the muscle seems to improve more in women than in men.

Cardiovascular reactions to cold exposures differ with age and gender

1985 ◽  
Vol 58 (1) ◽  
pp. 187-192 ◽  
Author(s):  
J. A. Wagner ◽  
S. M. Horvath
Keyword(s):  
Cardiac Output ◽  
Cold Exposure ◽  
Total Peripheral Resistance ◽  
Peripheral Resistance ◽  
Similar Response ◽  
Age And Gender ◽  
Ambient Temperatures ◽  
Blood Flows ◽  
Older Subjects ◽  
And Gender

This study was conducted since virtually no information was available concerning age- and gender-related differences in cardiovascular adjustments to cold exposure. Men and women between the ages of 20 and 30 and 51 and 72 yr, wearing swim suits, rested for 2 h in 28, 20, 15, and 10 degrees C ambient temperatures (Ta), with 40% relative humidity. Cardiac output (Qc) and stroke volumes (Qs) were higher in younger than older subjects regardless of Ta. Cardiac output was not influenced by gender, but all cold exposures resulted in increased Qs and decreased heart rate in men but not women. Regardless of age or gender, Qc increased about 10% only during exposure to 10 degrees C. Cold exposure resulted in minimal increases in the mean systolic and diastolic pressures (Pa) of the younger subjects. The Pa of older subjects were higher than in the young during 28 degrees C exposures and increased during all cold exposures. Total peripheral resistance and forearm blood flows were higher in older than young subjects exposed to cold. Total peripheral resistance, systolic and diastolic Pa, and finger and forearm blood flows were not affected by gender, but hand plus forearm blood flows were higher in men than women exposed to 28 degrees C. Although Qc appeared adequate to meet increased oxygen demands of shivering in the older subjects, rising Pa may become limiting in extended exposures. A similar response in hypertensive or angina-prone individuals may result in some untoward responses.

Effects of fatigue duration and muscle type on voluntary and evoked contractile properties

1997 ◽  
Vol 82 (5) ◽  
pp. 1654-1661 ◽  
Author(s):  
D. G. Behm ◽  
D. M. M. St-Pierre
Keyword(s):  
Muscle Activation ◽  
Compound Muscle Action Potential ◽  
Maximum Voluntary Contraction ◽  
Voluntary Contraction ◽  
Contractile Properties ◽  
Plantar Flexors ◽  
Muscle Type ◽  
M Wave ◽  
Time To Peak ◽  
Muscle Action Potential

Behm, D. G., and D. M. M. St-Pierre. Effects of fatigue duration and muscle type on voluntary and evoked contractile properties. J. Appl. Physiol. 82(5): 1654–1661, 1997.—The effects of fatigue duration and muscle type on voluntary and evoked contractile properties were investigated with an isometric, intermittent, submaximal fatigue protocol. Four groups performed contractions of the plantar flexors and quadriceps at various intensities to produce long (LDF; 19 min 30 s)- and short-duration fatigue (SDF; 4 min 17 s). The LDF group had a significantly greater decrease in muscle activation than did the SDF group (12 vs. 5.8%) during recovery, although there was no difference in the impairment of maximum voluntary contraction force beyond 30 s of recovery. The significant decrease in the compound muscle action potential of the LDF group (M-wave amplitude; 14.7%) contrasted with the M-wave potentiation of the SDF group (15.7%), suggesting changes in membrane excitation may affect LDF. The quadriceps group performing contractions at 50% MVC experienced a smaller decrease in agonist electromyograph activity than did other groups, indicating both muscle and fatigue duration specificity. Impairments in excitation-contraction coupling were indicated by changes in quadriceps peak twitch and time to peak twitch while decreases in PF M-wave amplitudes suggested a disruption of membrane potentials. Results suggest that fatigue mechanisms may be duration (activation, half relaxation time) or muscle specific (electromyograph, twitch torque) or a combination of both (M wave, time to peak twitch torque).

Prior muscle activation affects the compound muscle action potential

2019 ◽  
Author(s):  
Gordon W. Peterson ◽  
Bryan E. Tsao ◽  
Laura D. Nist ◽  
Dennys Estevez ◽  
Murray E. Brandstater
Keyword(s):  
Action Potential ◽  
Muscle Activation ◽  
Compound Muscle Action Potential ◽  
Muscle Action ◽  
Muscle Action Potential

Sex differences in human skeletal muscle fatigue are eliminated under ischemic conditions

2003 ◽  
Vol 94 (6) ◽  
pp. 2414-2422 ◽  
Author(s):  
David W. Russ ◽  
Jane A. Kent-Braun
Keyword(s):  
Sex Differences ◽  
Muscle Fatigue ◽  
Compound Muscle Action Potential ◽  
Muscle Metabolism ◽  
Tetanic Force ◽  
Central Activation ◽  
Primary Mechanism ◽  
Muscle Action Potential ◽  
Activation Ratio ◽  
The Difference

Several studies have suggested that women may be more resistant to muscle fatigue than men (Fulco CS, Rock PB, Muza SA, Lammi E, Cymerman A, Butterfield G, Moore, LG, Braun B, and Lewis SF. Acta Physiol Scand 167: 233–239, 1999) possibly because of differences in muscle oxidative metabolism. We evaluated muscle fatigue produced by intermittent, maximal volitional isometric contractions of the dorsiflexor muscles of healthy young (21–34 yr) men ( n = 8) and women ( n = 8) under two conditions: free-flow (FF) circulation and ischemia. Measures of voluntary and stimulated (10- and 50-Hz) force, central activation ratio (CAR), and compound muscle action potential (CMAP) were collected in each session. The ischemic protocol induced greater fatigue than the FF protocol, in both sexes, and was associated with greater reductions in CAR, CMAP, stimulated force, and the ratio of 10- to 50-Hz force compared with the FF condition. Women fatigued less than men in FF but not during ischemia, and this difference was roughly paralleled by a difference in CAR. No sex effects on the CMAP, tetanic force, and measures of excitation-contraction coupling function were found in the FF condition, suggesting that the primary mechanism behind the difference in fatigue was a relatively greater impairment of central activation in men. The observation that ischemia eliminated the sex differences in fatigue is consistent with a number of studies (Kent-Braun JA, Ng AV, Doyle JW, and Towse TF. J Appl Physiol93: 1813–1823, 2002) relating fatigue to muscle metabolism and might be the result of sex-based differences in metabolic pathway utilization during muscle contraction.

scholarly journals Possible interaction of gender and age on human swallowing behavior

2011 ◽  
Vol 48 (3) ◽  
pp. 195-198 ◽  
Author(s):  
Roberto Oliveira Dantas ◽  
Leda Maria Tavares Alves ◽  
Carla Manfredi dos Santos ◽  
Rachel de Aguiar Cassiani
Keyword(s):  
Older Women ◽  
Healthy Subjects ◽  
Middle Aged ◽  
Age And Gender ◽  
Gender Influence ◽  
Gender And Age ◽  
Older Subjects ◽  
Aged Subjects ◽  
And Gender ◽  
Effect Of Age

CONTEXT: The swallowing behavior is affected by age and possibly by gender. However, the interaction of the effects of age and gender on swallowing is not completely known. OBJECTIVES: To evaluate the possibility of interaction of gender and age on human swallowing behavior. METHOD: Swallowing was evaluated in 89 healthy subjects by the water swallowing test, 43 men and 46 women aged 20-40 years (younger, n = 38), 41-60 years (middle-aged, n = 31) and 61-80 years (older, n = 20). Each subject ingested in triplicate 50 mL of water while precisely timed and the number of swallows needed to ingest all the volume was counted. RESULTS: The interval between swallows was shorter and the volume in each swallow was smaller in women compared to men. In older subjects the time to ingest the 50 mL of water was longer, the interval between swallows was longer, and swallowing flow and volume in each swallow were smaller than in younger and middle-aged subjects. The swallowing flow was lower in women compared to men in younger subjects. The volume of each swallow was smaller in women than in men in younger and middle-aged subjects. There was no difference in swallowing flow and volume between older men and older women. CONCLUSION: Age and gender influence swallowing behavior, with the effect of gender being more evident in younger subjects and the effect of age being more evident in men.

scholarly journals Effects of Age and Gender on Hand Motion Tasks

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Wing Lok Au ◽  
Irene Soo Hoon Seah ◽  
Wei Li ◽  
Louis Chew Seng Tan
Keyword(s):  
Multivariate Analyses ◽  
Motion Sensor ◽  
Kinematic Parameters ◽  
Age And Gender ◽  
Hand Motion ◽  
Factors Influencing ◽  
Age And Gender Differences ◽  
Hand Grasp ◽  
Older Subjects ◽  
And Gender

Objective. Wearable and wireless motion sensor devices have facilitated the automated computation of speed, amplitude, and rhythm of hand motion tasks. The aim of this study is to determine if there are any biological influences on these kinematic parameters.Methods. 80 healthy subjects performed hand motion tasks twice for each hand, with movements measured using a wireless motion sensor device (Kinesia, Cleveland Medical Devices Inc., Cleveland, OH). Multivariate analyses were performed with age, gender, and height added into the model.Results. Older subjects performed poorer in finger tapping (FT) speed (r=0.593,p<0.001), hand-grasp (HG) speed (r=0.517,p<0.001), and pronation-supination (PS) speed (r=0.485,p<0.001). Men performed better in FT rhythmp<0.02, HG speedp<0.02, HG amplitudep<0.02, and HG rhythmp<0.05. Taller subjects performed better in the speed and amplitude components of FTp<0.02and HG tasksp<0.02. After multivariate analyses, only age and gender emerged as significant independent factors influencing the speed but not the amplitude and rhythm components of hand motion tasks. Gender exerted an independent influence only on HG speed, with better performance in menp<0.05.Conclusions. Age, gender, and height are not independent factors influencing the amplitude and rhythm components of hand motion tasks. The speed component is affected by age and gender differences.

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