共查询到20条相似文献,搜索用时 78 毫秒
1.
Whitman SA Wacker MJ Richmond SR Godard MP 《Pflügers Archiv : European journal of physiology》2005,450(6):437-446
The primary mechanism that contributes to decreasing skeletal muscle strength and size with healthy aging is not presently known. This study examined the contribution of the ubiquitin–proteasome pathway and apoptosis to skeletal muscle wasting in older adults (n = 21; mean age = 72.76 ± 8.31 years) and young controls (n = 21; mean age = 21.48 ± 2.93 years). Subjects underwent a percutaneous muscle biopsy of the vastus lateralis to determine: (1) ubiquitin ligase gene expression (MAFbx and MuRF1); (2) frequency of apoptosis; and (3) individual fiber type and cross-sectional area. In addition, a whole muscle strength test was also performed. A one-way ANOVA revealed significant increases in the number of positive TUNEL cells in older adults (87%; p < 0.05), although no significant increase in caspase-3/7 activity was detected. Additionally, ubiquitin ligase gene expression, individual muscle fiber type and CSA were not different between old and young subjects. Muscle strength was also significantly lower in old compared to young subjects (p < 0.05). In conclusion, this study indicates a preferential role for apoptosis contributing to decreases in muscle function with age. 相似文献
2.
Brent A. Baker Melinda S. Hollander Michael L. Kashon Robert G. Cutlip 《European journal of applied physiology》2010,108(3):619-630
The involvement of glutathione in the response of skeletal muscle following repetitive, high-intensity mechanical loading
is not known. We examined the influence of a glutathione antagonist [l-Buthionine Sulfoximine (BSO)] had on the adaptability of skeletal muscle during chronic mechanical loading via stretch-shortening
contractions (SSCs) in young and old rats. Left dorsiflexor muscles of young (12 weeks, N = 16) and old (30 months, N = 16), vehicle- and BSO-treated rats were exposed three times per week for 4.5-weeks to a protocol of 80 maximal SSCs per
exposure in vivo. Skeletal muscle response to the SSC exposure was characterized by muscle performance, as well as muscle wet-weight and quantitative
morphological analyses following the exposure period. Results reveal that generally, muscle performance increased in the young
rats only following chronic SSC exposure. BSO treatment had no effect on muscle performance or morphology following the chronic
SSC exposure in old rats. Muscle wet-weight was increased following exposure compared with the contra-lateral control limb,
irrespective of age (p < 0.05). Muscle cross-sectional area increased approximately 20% with SSC loading in the young, vehicle rats, while increasing
approximately 10% with SSC loading in old, vehicle rats compared with control rat muscle. No degenerative myofibers were noted
in either age group, but edema were increased as a result of aging (p < 0.05). We conclude that our results indicate that glutathione depletion does not adversely affect muscle performance or
morphology in old rats. Nevertheless, we continue to show that aging negatively influences performance and morphology following
chronic SSC exposure. 相似文献
3.
Doa El-Ansary Charlotte J. Marshall Joshua Farragher Raquel Annoni Ariane Schwank James McFarlane Adam Bryant Jia Han Marilyn Webster Guy Zito Selina Parry Adrian Pranata 《Journal of anatomy》2021,239(4):847-855
Quadriceps atrophy and morphological change is a known phenomenon that can impact significantly on strength and functional performance in patients with acute or chronic presentations conditions. Real-time ultrasound (RTUS) imaging is a noninvasive valid and reliable method of quantifying quadriceps muscle anatomy and architecture. To date, there is a paucity of normative data on the architectural properties of superficial and deep components of the quadriceps muscle group to inform assessment and evaluation of intervention programs. The aims of this study were to (1) quantify the anatomical architectural properties of the quadriceps muscle group (rectus femoris, vastus intermedius, and vastus lateralis) using RTUS in healthy older adults and (2) to determine the relationship between RTUS muscle parameters and measures of quadriceps muscle strength. Thirty middle aged to older males and females (age range 55–79 years; mean age =59.9 ± 7.08 years) were recruited. Quadriceps muscle thickness, cross-sectional area, pennation angle, and echogenicity were measured using RTUS. Quadriceps strength was measured using hand-held dynamometry. For the RTUS-derived quadriceps morphological data, rectus femoris mean results; circumference 9.3 cm; CSA 4.6 cm2; thickness 1.5 cm; echogenicity 100.2 pixels. Vastus intermedius mean results; thickness 1.8 cm; echogenicity 99.1 pixels. Vastus lateralis thickness 1.9 cm; pennation angle 17.3 ° ; fascicle length 7.0 cm. Quadriceps force was significantly correlated only with rectus femoris circumference (r = 0.48, p = 0.007), RF echogenicity (r = 0.38, p = 0.037), VI echogenicity (r = 0.43, p = 0.018), and VL fascicle length (r = 0.43, p = 0.019). Quadriceps force was best predicted by a three-variable model (adjusted R2 = 0.46, p < 0.001) which included rectus femoris echogenicity (B = 0.43, p = 0.005), vastus lateralis fascicle length (B = 0.33, p = 0.025) and rectus femoris circumference (B = 0.31, p = 0.041). Thus respectively, rectus femoris echogenicity explains 43%, vastus lateralis fascicle length explains 33% and rectus femoris circumference explains 31% of the variance of quadriceps force. The study findings suggest that RTUS measures were reliable and further research is warranted to establish whether these could be used as surrogate measures for quadriceps strength in adults to inform exercise and rehabilitation programs. 相似文献
4.
D. J. Tomlinson R. M. Erskine K. Winwood C. I. Morse G. L. Onambélé 《Journal of anatomy》2014,225(6):675-684
It is unknown whether loading of the lower limbs through additional storage of fat mass as evident in obesity would promote muscular adaptations similar to those seen with resistance exercise. It is also unclear whether ageing modulates any such adjustments. This study aimed to examine the relationships between adiposity, ageing and skeletal muscle size and architecture. A total of 100 untrained healthy women were categorised by age into young (Y) (mean ± SD: 26.7 ± 9.4 years) vs. old (O) (65.1 ± 7.2 years) and body mass index (BMI) classification (underweight, normal weight, overweight and obese). Participants were assessed for body fat using dual energy x‐ray absorptiometry, and for gastrocnemius medialis (GM) muscle architecture (skeletal muscle fascicle pennation angle and length) and size [GM muscle volume and physiological cross‐sectional area (PCSA)] using B‐mode ultrasonography. GM fascicle pennation angle (FPA) in the obese Y females was 25% greater than underweight (P = 0.001) and 25% greater than normal weight (P = 0.001) individuals, while O females had 32 and 22% greater FPA than their underweight (P = 0.008) and normal weight (P = 0.003) counterparts. Furthermore, FPA correlated with body mass in both Y and O females (Y r = 0.303; P < 0.001; O r = 0.223; P = 0.001), yet no age‐related differences in the slope or r‐values were observed (P > 0.05). Both GM muscle volume (P = 0.003) and PCSA (P = 0.004) exhibited significant age × BMI interactions. In addition, muscle volume and PCSA correlated with BMI, body mass and fat mass. Interestingly, ageing reduced both the degree of association in these correlations (P < 0.05) and the slope of the regressions (P < 0.05). Our findings partly support our hypotheses in that obesity‐associated changes in GM PCSA and volume differed between the young and old. The younger GM muscle adapted to the loading induced by high levels of body mass, adiposity and BMI by increasing its volume and increasing its pennation angle, ultimately enabling it to produce higher maximum torque. Such an adaptation to increased loading did not occur in the older GM muscle. Nonetheless, the older GM muscle FPA increased to a similar extent to that seen in young GM muscle, an effect which partly explains the relatively enhanced absolute maximum torque observed in obese older females. 相似文献
5.
Joaquin U. Gonzales John R. Thistlethwaite Benjamin C. Thompson Barry W. Scheuermann 《European journal of applied physiology》2009,106(5):779-784
Shear stress is the frictional force of blood against the endothelium, a stimulus for endothelial activation and the release
of von Willebrand factor (vWF). This study tested the hypothesis that the increase in shear stress associated with exercise
correlates with plasma vWF. Young (n = 14, 25.7 ± 5.4 years) and older (n = 13, 65.6 ± 10.7 years) individuals participated in 30 min of dynamic handgrip exercise at a moderate intensity. Brachial
artery diameter and blood flow were measured using ultrasound Doppler and blood samples were collected before, immediately
after, and following 30 min of recovery from exercise with plasma levels of vWF. Plasma levels of vWF increased (P < 0.05) by 6 ± 2% in young individuals and 4 ± 1% in older individuals immediately after exercise. The change in plasma vWF
was linearly correlated with the increase in shear stress during exercise in older individuals (post-exercise: r = 0.78, 30 min recovery: r = 0.77, P < 0.01), but no association was found in the young individuals. These changes in plasma levels of vWF in humans suggest that
aging influences endothelial activation and hemostasis. 相似文献
6.
We compared two methods to determine IL-6 at rest and following exercise. On two occasions, plasma IL-6 was determined in
10 men and 13 women before and immediately following 90 min of cycling at 65% using a cytometric bead array (CBA) and an ELISA. The CBA detected IL-6 in 63% of pre-exercise samples and 84% of post-exercise
samples; the ELISA detected IL-6 in all samples. In samples with detectable IL-6, resting values were comparable between the
CBA and ELISA (2.3 ± 1.0 and 2.4 ± 1.2 pg/mL, respectively; p = 0.99); the IL-6 response to exercise was underestimated (p = 0.0003) by the CBA by ~45%, compared with the ELISA. CBA- and ELISA-determined IL-6 values were moderately correlated (r = 0.66, p < 0.0001), but exhibited poor agreement (mean bias ± 1SD = −1.4 ± 2.1 pg/mL). The CBA provided concordant IL-6 concentrations
at rest, when detected, but underestimated exercise-induced increases in IL-6 versus the ELISA method. 相似文献
7.
Tracey McCauley Sarabjit S. Mastana Jonathan P. Folland 《European journal of applied physiology》2010,109(2):269-277
The progressive decline in strength and power with ageing leads to compromised mobility and an increased risk of falls. Angiotensin
converting enzyme (ACE) I/D and alpha actinin 3 (ACTN3) R/X polymorphisms have been suggested to influence variations in skeletal
muscle function and body composition. This study investigated the associations between these polymorphisms and knee extensor
muscle function and muscularity in older Caucasian men. Strength was measured isometrically and isokinetically (at 30 and
240° s−1), and the time course of the evoked twitch response recorded. A dual-energy X-ray absorptiometry scan measured thigh and
whole body non-skeletal lean mass. ACE I/D and ACTN3 R/X polymorphisms were determined by polymerase chain reaction, and serum
ACE activity using spectrophotometry. Whole body and thigh non-skeletal lean mass were independent of ACE and ACTN3 genotypes.
Absolute and relative high velocity strength, and the time course of an evoked twitch were not associated with ACE or ACTN3
genotype. Serum ACE activity was negatively correlated with relative high velocity torque (R = −0.23, P = 0.03), and exhibited a positive trend with knee extensor isometric strength (R = 0.19, P = 0.07). ACE I/D and ACTN3 R/X polymorphisms were not associated with muscle function or muscularity phenotypes in older
Caucasian men, although serum ACE activity appeared to have a small effect on muscle function. 相似文献
8.
Murakami H Iemitsu M Sanada K Gando Y Ohmori Y Kawakami R Sasaki S Tabata I Miyachi M 《European journal of applied physiology》2011,111(12):2997-3005
Elevated fasting plasma homocysteine (Hcy) level is a vascular disease risk factor. Plasma Hcy is affected by 5,10-methylenetetrahydofolate
reductase (MTHFR) genotype and dietary folate intake. This cross-sectional study in 434 Japanese adults examined the associations
among objectively measured physical activity (PA), plasma Hcy adjusting for dietary folate intake, and MTHFR C677T genotype.
Daily PA was measured by triaxial accelerometry and all subjects completed a questionnaire about their dietary habits. Plasma
Hcy and MTHFR C677T genotype were determined. Plasma Hcy in subjects with the TT genotype was significantly higher than in
those with CC or CT genotype (p < 0.001). Plasma Hcy was significantly different between ≥200 (7.6 ± 0.2 nmol/mL) and <200 μg/day (8.3 ± 0.3 nmol/mL) folate
intake groups (p = 0.003). There were no differences in plasma Hcy adjusting for age, sex, and folate intake between groups according to PA
category in all subjects. However, there were significant interactions between time spent in light PA (p = 0.003), vigorous PA (p = 0.001), or inactivity (p = 0.004), and MTHFR genotype. In only the TT genotype, shorter time spent in light PA was associated with higher plasma Hcy
than a longer time spent in light PA (11.5 ± 3.3 nmol/mL vs. 8.5 ± 3.3 nmol/mL, p < 0.001), and longer time spent in vigorous PA and inactivity were associated with higher plasma Hcy (11.8 ± 3.3 nmol/mL
vs. 8.4 ± 3.2 nmol/mL, 11.6 ± 3.3 nmol/mL vs. 8.4 ± 3.3 nmol/mL, respectively, p < 0.001). In conclusion, light and vigorous PA were associated with plasma Hcy only in the TT genotype, but there were no
such associations in all genotypes. 相似文献
9.
The effect of strength training and short-term detraining on maximum force and the rate of force development of older men 总被引:1,自引:0,他引:1
This study examined the effect of strength training (ST) and short-term detraining on maximum force and rate of force development
(RFD) in previously sedentary, healthy older men. Twenty-four older men (70–80 years) were randomly assigned to a ST group
(n = 12) and C group (control, n = 12). Training consisted of three sets of six to ten repetitions on an incline squat at 70–90% of one repetition maximum
three times per week for 16 weeks followed by 4 weeks of detraining. Regional muscle mass was assessed before and after training
by dual-energy X-ray absorptiometry. Training increased RFD, maximum bilateral isometric force, and force in 500 ms, upper
leg muscle mass and strength above pre-training values (14, 25, 22, 7, 90%, respectively; P < 0.05). After 4 weeks detraining all neuromuscular variables were significantly (P < 0.05) lower than after 16 weeks training but remained significantly (P < 0.05) higher than pre-training levels except for RFD which had returned to pre-training levels. These findings demonstrate
that high-intensity ST can improve maximum force and RFD of older men. However, older individuals may lose some neuromuscular
performance after a period of short-term detraining and that resistance exercise should be performed on a regular basis to
maintain training adaptations. 相似文献
10.
Hunter GR Bickel CS Del Corral P Byrne NM Hills AP Larson-Meyer DE Bamman MM Newcomer BR 《European journal of applied physiology》2011,111(4):715-723
Aging is associated with loss of endurance; however, aging is also associated with decreased fatigue during maximal isometric
contractions. The aims of this study were to examine the relationship between age and walking endurance (WE) and maximal isometric
fatigue (MIF) and to determine which metabolic/fitness components explain the expected age effects on WE and MIF. Subjects
were 96 pre-menopausal women. Oxygen uptake (walking economy) was assessed during a 3-mph walk; aerobic capacity and WE by
progressive treadmill test; knee extension strength by isometric contractions, MIF during a 90-s isometric plantar flexion
(muscle metabolism measured by 31P MRS). Age was related to increased walking economy (low VO2, r = −0.19, P < 0.03) and muscle metabolic economy (force/ATP, 0.34, P = 0.01), and reduced MIF (−0.26, P < 0.03). However, age was associated with reduced WE (−0.28, P < 0.01). Multiple regression showed that muscle metabolic economy explained the age-related decrease in MIF (partial r for MIF and age −0.13, P = 0.35) whereas walking economy did not explain the age-related decrease in WE (partial r for WE and age −0.25, P < 0.02). Inclusion of VO2max and knee endurance strength accounted for the age-related decreased WE (partial r for WE and age = 0.03, P > 0.80). In premenopausal women, age is related to WE and MIF. In addition, these results support the hypothesis that age-related
increases in metabolic economy may decrease MIF. However, decreased muscle strength and oxidative capacity are related to
WE. 相似文献
11.
Sood S Hanson ED Delmonico MJ Kostek MC Hand BD Roth SM Hurley BF 《European journal of applied physiology》2012,112(2):743-753
The CA-repeat polymorphism in the insulin-like growth factor 1 (IGF1) gene promoter region has been associated with strength and circulating IGF-I protein levels. The purpose of the study was
to determine if the IGF1 CA-repeat polymorphism influences muscle power at baseline and in response to ST in older adults. Knee extensor peak power
(PP) was measured at 50, 60, and 70% of 1-RM strength before and after 10 weeks of unilateral knee extensor ST in older adults,
aged 50–85 years, to determine the changes in absolute and relative PP with ST. Subjects (N = 114) were genotyped for the IGF1 CA-repeat polymorphism and grouped as homozygous for the 192 allele, heterozygous, or non-carriers of the 192 allele. The
192 homozygotes had significantly lower baseline PP at 50, 60, and 70% of 1-RM strength than the non-carriers when age, sex,
and baseline fat-free mass were covaried (all P < 0.05). This same relationship was observed when the highest PP within these ranges was compared (e.g., 317.6 ± 13.5 for
192 homozygotes and 380.2 ± 16.3 for non-carriers of the 192 allele, P < 0.05). Both absolute and relative PP increased significantly with ST in all genotype groups as expected, but there were
no significant relationships among IGF1 genotypes and any of the PP changes. Despite a significant relationship between IGF1 genotype and knee extensor peak power at baseline, IGF1 genotype does not appear to influence changes in knee extensor peak power with ST. 相似文献
12.
Ana Carolina de Miranda Marzullo Osmar Pinto Neto Kirrie J. Ballard Donald A. Robin Lauren Chaitow Evangelos A. Christou 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》2010,206(3):319-327
Aging impairs the control of many skilled movements including speech. The purpose of this paper was to investigate whether
young and older adults adapt to lower lip perturbations during speech differently. Twenty men (10 young, 26 ± 3 years of age;
10 older, 60 ± 9 years of age) were requested to repeat the word (“papa”) 300 times. In 15% of the trials, the subjects experienced
a mechanical perturbation on the lower lip. Displacement and neural activation (EMG) of the upper and lower lips were evaluated.
Perturbations to the lower lip caused a greater increase in the maximum displacement of the lower lip for older adults compared
with young adults (34.7 ± 19% vs. 13.4 ± 17%; P = 0.017). Furthermore, young adults exhibited significantly greater 30–100 Hz normalized EMG power for the lower lip compared
to the upper lip (P < 0.005). In young adults, changes from normal to perturbed trials in the 30–50 Hz frequency band of the EMG were negatively
correlated to the changes from normal to perturbed trials in the lower lip maximum displacement (R
2 = 0.48; P = 0.025). It is concluded that young adults adapt better to lower lip perturbations compared with older adults and that the
associated neural activation strategy of the involved muscle is different for the two age groups. 相似文献
13.
Garry A. Tew Markos Klonizakis John M. Saxton 《European journal of applied physiology》2010,109(2):173-181
The impact of cardiopulmonary fitness ([(V)\dot] \dot{V} O2max) on the age-related decline in skin-microvessel vasodilator function has not been fully established and the inter-relationships
among different measures of microvascular vasodilator function are unknown. We used laser Doppler flowmetry to assess relative
changes in forearm skin blood flow to various stimuli in three groups of adults: young (n = 15; 27 ± 2 years), older sedentary (n = 14; 65 ± 6 years) and older fit (n = 15; 61 ± 5 years). Local-heating induced and post-occlusive hyperaemia responses were higher in the young and older fit
groups compared to the older sedentary group (P < 0.05) and were moderately correlated with [(V)\dot] \dot{V} O2max in the pooled cohort of older adults (r = 0.49–0.58; P < 0.05). Peak hyperaemia responses to acetylcholine and sodium nitroprusside were higher in young compared to older sedentary
adults (P < 0.05) and were not associated with [(V)\dot] \dot{V} O2max in older adults (P > 0.05). Associations among different measures of microvascular vasodilator function were generally moderate at best. In
summary, the local heating and reactive hyperaemia data indicate that the age-related decline in skin-microvessel vasodilator
function can be ameliorated through regular aerobic exercise training. As this is not supported by the iontophoresis data,
we recommend that, when assessing microvascular function, the use of a single physiological or pharmacological stimulation
coupled to laser Doppler flowmetry should be avoided. Finally, the moderate correlations between outcomes probably reflect
the distinct mediators that are responsible for the vasodilator response to each test. 相似文献
14.
The aim of this study was to investigate the connection between local inflammation of the peritoneal membrane and diuresis,
as well as the residual renal function (RRF) in patients treated with continuous ambulatory peritoneal dialysis (CAPD). Twenty
patients treated with CAPD participated in this cross-sectional study. To determine the influence of local inflammation of
the peritoneal membrane, effluent interleukin-6 (IL-6) and soluble interleukin-6 receptor (sIL-6R) levels were measured. The
level of IL-6, in the group as a whole, was significantly higher in effluent (7.87 pg/mL) than in serum (1.29 pg/mL). There
was a significant correlation between effluent and serum IL-6 (r = 0.608; P = 0.002). There was also a significant relationship between effluent and serum IL-6 and duration of CAPD treatment, respectively
(r = 0.577; P = 0.004; r = 0.528; P = 0.008). Further, there was a significant negative correlation between effluent IL-6 and daily diuresis (r = −0.533; P = 0.008), but there was no significant correlation between effluent IL-6 and RRF (r = −0.339, P = 0.072). On the other hand, the concentrations of effluent IL-6 were significantly higher in patients with RRF <2 mL/min
than in those with RRF ≥2 mL/min (P = 0.039). In conclusion, local inflammation has a significant impact on the amount of diuresis and probably on RRF in patients
on CAPD. 相似文献
15.
Kouda K Furusawa K Sugiyama H Sumiya T Ito T Tajima F Shimizu K 《European journal of applied physiology》2012,112(2):597-604
Interleukin-6 (IL-6) is produced by contracting skeletal muscles and then released into the circulation and considered to
mediate the health benefits of exercise against chronic diseases. Individuals with spinal cord injury (SCI) are reported to
be at higher risk of developing metabolic diseases. We investigated the IL-6 responses to 20-min arm crank ergometer exercise
at 60% of maximum oxygen consumption in eight trained individuals with cervical SCI (CSCI) between C6 and C7, and eight able-bodied
trained healthy subjects. The plasma concentrations of IL-6, adrenaline, prostaglandin E2 and cortisol were measured before, immediately after the exercise, 1 and 2 h after exercise. At rest, the plasma adrenaline
concentration was significantly lower in individuals with CSCI than in able-bodied subjects (P < 0.01). On the other hand, the concentration of IL-6 was significantly higher at rest in individuals with CSCI (2.18 ± 0.44 pg/ml,
mean ± SEM) than the control (1.02 ± 0.22 pg/ml, P < 0.05). In able-bodied subjects, the plasma adrenaline concentration increased significantly immediately after the exercise
(P < 0.01) and returned to the baseline level at 1 h after exercise, and the plasma IL-6 level increased significantly at 1 h
after exercise (1.91 ± 0.28 pg/ml, P < 0.05) and returned to the baseline level at 2 h after exercise. In contrast, adrenaline and IL-6 levels were steady throughout
the study in individuals with CSCI. The lack of exercise-related IL-6 response in individuals with CSCI could be due to muscle
atrophy and sympathetic nervous system dysfunction. 相似文献
16.
Stéphanie Vieillevoye Jacques R. Poortmans Jacques Duchateau Alain Carpentier 《European journal of applied physiology》2010,110(3):479-488
Increase in myofibrillar protein accretion can occur in the very early post-exercise period and can be potentiated by ingestion
of essential amino acid (EAA). Furthermore, strength exercise induces important disturbances in protein turnover, especially
in novice athletes. The purpose of this investigation was to evaluate the effects of an EAA supplementation on muscle mass,
architecture and strength in the early stages of a heavy-load training programme. 29 young males trained during 12 weeks.
They were divided into a placebo (PLA) (n = 14) group and an EAA group (n = 15). At baseline, daily food intake and nitrogenous balance were assessed with a food questionnaire over 7 days and two
24-h urine collections. The effect of training on muscle mass was assessed by anthropometric techniques. Muscle thickness
and pennation angle were recorded by ultrasonography of the gastrocnemius medialis (GM). Maximal strength during squat and
bench press exercises were tested on an isokinetic ergometer. Training resulted in significant increase in muscle mass and
strength in both PLA and EAA groups. Positive linear regressions were found between nitrogen balance and increase in muscle
mass in the PLA group (P < 0.01, r2 = 0.63) and between the initial strength and the increase in muscle strength in the EAA group (P < 0.05, r2 = 0.29). EAA ingestion resulted in greater changes in GM muscle architecture. These data indicate that EAA supplementation
has a positive effect on muscle hypertrophy and architecture and that such a nutritional intervention seems to be more effective
in subject having lower nitrogen balance and/or lower initial strength. 相似文献
17.
Johanna Schwarz John Axelsson Andreas Gerhardsson Sandra Tamm Hkan Fischer Gran Kecklund Torbjrn kerstedt 《Journal of sleep research》2019,28(4)
Sleep deprivation commonly impairs affective regulation and causes worse mood. However, the majority of previous research concerns young adults. Because susceptibility to sleep deprivation and emotion regulation change distinctively across adult age, we tested here the hypothesis that the effect of sleep deprivation on mood is stronger in young than in older adults. In an experimental design, young (18–30 years) and older adults (60–72 years) participated in either a sleep control (young, n = 63; older, n = 47) or a total sleep deprivation condition (young, n = 61; older, n = 47). Sleepiness, mood and common symptoms of sleep deprivation were measured using established questionnaires and ratings. Sleep‐deprived participants felt more sleepy, stressed and cold, and reported lower vigour and positive affect, regardless of age. All the other outcome measures (negative affect, depression, confusion, tension, anger, fatigue, total mood disturbance, hunger, cognitive attenuation, irritability) showed a weaker response to sleep deprivation in the older group, as indicated by age*sleep deprivation interactions (ps < 0.05). The results show that older adults are emotionally less affected by sleep deprivation than young adults. This tolerance was mainly related to an attenuated increase in negative mood. This could possibly be related to the well‐known positivity effect, which suggests that older adults prioritize regulating their emotions to optimize well‐being. The results also highlight that caution is warranted when generalizing results from sleep deprivation studies across the adult lifespan. 相似文献
18.
Candow DG Chilibeck PD Facci M Abeysekara S Zello GA 《European journal of applied physiology》2006,97(5):548-556
We determined the effects of protein supplementation immediately before (PRO-B) and after (PRO-A) resistance training (RT; 12 weeks) in older men (59–76 years), and whether this reduces deficits in muscle mass and strength compared to younger men (18–40 years). Older men were randomized to PRO-B (0.3 g/kg protein before RT + placebo after RT, n=9), PRO-A (placebo before + protein after RT, n=10), or PLA (placebo before and after RT, n=10). Lean tissue mass, muscle thickness of the elbow, knee, and ankle flexors and extensors, and leg and bench press strength were measured before and after RT and compared to databases of younger subjects (n=22–60). Myofibrillar protein degradation (3-methylhistidine) and bone resorption (cross-linked N-telopeptides) were also measured before and after RT. Lean tissue mass, muscle thickness (except ankle dorsi flexors), and strength increased with training (P<0.05), with little difference between groups. There were no changes in 3-methylhistidine or cross-linked N-telopeptides. Before RT, all measures were lower in the older compared to younger groups (P<0.05), except for elbow extensor muscle thickness. Following training, muscle thickness of the elbow flexors and ankle dorsi flexors and leg press strength were no longer different than the young, and elbow extensor muscle thickness was greater in the old men (P<0.05). Supplementation with protein before or after training has no effect on muscle mass and strength in older men. RT was sufficient to overcome deficits in muscle size of the elbow flexors and ankle dorsi flexors and leg press strength in older compared to younger men. 相似文献
19.
Skeletal muscle monocarboxylate transporter content is not different between black and white runners
Yolande X. R. Harley Tertius A. Kohn Alan St Clair Gibson Timothy D. Noakes Malcolm Collins 《European journal of applied physiology》2009,105(4):623-632
The superior performance of black African runners has been associated with lower plasma lactate concentrations at sub-maximal
intensities compared to white runners. The aim was to investigate the monocarboxylate transporters 1 (MCT1) and MCT4 content
in skeletal muscle of black and white runners. Although black runners exhibited lower plasma lactate concentrations after
maximum exercise (8.8 ± 2.0 vs. 12.3 ± 2.7 mmol l−1, P < 0.05) and a tendency to be lower at 16 km h−1 (2.4 ± 0.7 vs. 3.8 ± 2.4 mmol l−1, P = 0.07) than the white runners, there were no differences in MCT1 or MCT4 levels between the two groups. For black and white
runners together, MCT4 content correlated significantly with 10 km personal best time (r = −0.74, P < 0.01) and peak treadmill speed (r = 0.88, P < 0.001), but MCT1 content did not. Although whole homogenate MCT content was not different between the groups, more research
is required to explain the lower plasma lactate concentrations in black runners. 相似文献
20.
Wagner S Knechtle B Knechtle P Rüst CA Rosemann T 《European journal of applied physiology》2012,112(3):1095-1106
We investigated the prevalence of exercise-associated hyponatremia (EAH) in 25 male and 11 female open-water ultra-endurance
swimmers participating in the ‘Marathon-Swim’ in Lake Zurich, Switzerland, covering a distance of 26.4 km. Changes in body
mass, fat mass, skeletal muscle mass, total body water, urine specific gravity, plasma sodium concentration [Na+] and haematocrit were determined. Two males (8%) and four females (36%) developed EAH where one female was symptomatic with
plasma sodium [Na+] of 127 mmol/L. Body mass and plasma [Na+] decreased (p < 0.05). The changes in body mass correlated in both male and female swimmers to post-race plasma [Na+] (r = −0.67, p = 0.0002 and r = −0.80, p = 0.0034, respectively) and changes in plasma [Na+] (r = −0.68, p = 0.0002 and r = −0.79, p = 0.0039, respectively). Fluid intake was neither associated with changes in body mass, post-race plasma [Na+] or the change in plasma [Na+]. Sodium intake showed no association with either the changes in plasma [Na+] or post-race plasma [Na+]. We concluded that the prevalence of EAH was greater in female than in male open-water ultra-endurance swimmers. 相似文献