scholarly journals Age-related differences in performance and fatigability during an isometric quadriceps intermittent fatigue test

2021 ◽  
Author(s):  
Giorgio Varesco ◽  
Eric Luneau ◽  
Léonard Féasson ◽  
Thomas Lapole ◽  
Vianney Rozand
Keyword(s):  
Older Adults ◽  
Contractile Function ◽  
Age Groups ◽  
Femoral Nerve ◽  
Voluntary Activation ◽  
Knee Extensors ◽  
Men And Women ◽  
Very Old ◽  
Old Adults ◽  
Age Related

AbstractThe aim of the present study was to investigate age-related differences in fatigability induced by an isometric quadriceps intermittent fatiguing test in young (<35 years old), old (>60 years old) and very old (>80 years old) men and women. Maximal force loss, contractile function and voluntary activation of the knee extensors were evaluated throughout an isometric fatiguing test using femoral nerve magnetic stimulations. Older adults performed more contractions (index of relative performance) than young (P = 0.046) and very old adults (P = 0.007), without differences between young and very old adults. Total work (absolute performance) was greater for young and old adults compared to very old adults (P < 0.001), without differences between young and old adults. At exhaustion, force loss was greater for young (−28 ± 9%) compared to old adults (−19 ± 8%), but not very old adults (−23 ± 8%). The response to femoral nerve stimulation decreased similarly at exhaustion for the three age groups, indicating similar alteration in contractile function with age. No impairment in voluntary activation was observed. Impairments in neuromuscular parameters were similar for men and women. This study showed that older adults were less fatigable than young adults during an isometric intermittent fatiguing task of the knee extensors. This greater fatigue resistance was not maintained in very old adults independent of sex. Fatigability at exhaustion was likely due to impairments in contractile function for the three age groups.

scholarly journals Mechanisms for the age-related increase in fatigability of the knee extensors in old and very old adults

2018 ◽  
Vol 125 (1) ◽  
pp. 146-158 ◽  
Author(s):  
Christopher W. Sundberg ◽  
Andrew Kuplic ◽  
Hamidollah Hassanlouei ◽  
Sandra K. Hunter
Keyword(s):  
High Velocity ◽  
Power Loss ◽  
Age Groups ◽  
Contractile Properties ◽  
Knee Extensors ◽  
Men And Women ◽  
Very Old ◽  
Old Adults ◽  
Age Related ◽  
Related Increase

The mechanisms for the age-related increase in fatigability during high-velocity contractions in old and very old adults (≥80 yr) are unresolved. Moreover, whether the increased fatigability with advancing age and the underlying mechanisms differ between men and women is not known. The purpose of this study was to quantify the fatigability of knee extensor muscles and identify the mechanisms of fatigue in 30 young (22.6 ± 0.4 yr; 15 men), 62 old (70.5 ± 0.7 yr; 33 men), and 12 very old (86.0 ± 1.3 yr; 6 men) men and women elicited by high-velocity concentric contractions. Participants performed 80 maximal velocity contractions (1 contraction per 3 s) with a load equivalent to 20% of the maximum voluntary isometric contraction. Voluntary activation and contractile properties were quantified before and immediately following exercise (<10 s) using transcranial magnetic stimulation and electrical stimulation. Absolute mechanical power output was 97 and 217% higher in the young compared with old and very old adults, respectively. Fatigability (reductions in power) progressively increased across age groups, with a power loss of 17% in young, 31% in old, and 44% in very old adults. There were no sex differences in fatigability among any of the age groups. The age-related increase in power loss was strongly associated with changes in the involuntary twitch amplitude ( r = 0.75, P < 0.001). These data suggest that the age-related increased power loss during high-velocity fatiguing exercise is unaffected by biological sex and determined primarily by mechanisms that disrupt excitation contraction coupling and/or cross-bridge function. NEW & NOTEWORTHY We show that aging of the neuromuscular system results in an increase in fatigability of the knee extensors during high-velocity exercise that is more pronounced in very old adults (≥80 yr) and occurs similarly in men and women. Importantly, the age-related increase in power loss was strongly associated with the changes in the electrically evoked contractile properties suggesting that the increased fatigability with aging is determined primarily by mechanisms within the muscle for both sexes.

Examining Positivity Effect and Working Memory in Young-Old and Very Old Adults Using EEG-Derived Cognitive State Metrics

2019 ◽  
Vol 41 (10) ◽  
pp. 1014-1035
Author(s):  
Joelle C. Ruthig ◽  
Dmitri P. Poltavski ◽  
Thomas Petros
Keyword(s):  
Older Adults ◽  
Working Memory ◽  
Memory Task ◽  
Cognitive State ◽  
Emotional Stimuli ◽  
Very Old ◽  
Positivity Effect ◽  
Old Adults ◽  
Age Related ◽  
Young Old

The positivity effect among older adults is a tendency to process more positive and/or less negative emotional stimuli compared to younger adults, with unknown upper age boundaries. Cognitive and emotional working memory were assessed in young-old adults (60–75) and very old adults (VOAs; 80+) to determine whether emotional working memory declines similar to the age-related decline of cognitive working memory. The moderating role of valence on the link between age and emotional working memory was examined to identify change in positivity effect with advanced age. Electroencephalography (EEG) markers of cognitive workload and engagement were obtained to test the theory of cognitive resource allocation in older adults’ emotional stimuli processing. EEG recordings were collected during cognitive memory task and emotional working memory tasks that required rating emotional intensity of images pairs. Results indicate a positivity effect among VOAs that does not require additional cognitive effort and is not likely to diminish with age.

scholarly journals Neuromuscular changes of the aged human hamstrings

2018 ◽  
Vol 120 (2) ◽  
pp. 480-488 ◽  
Author(s):  
Eric A. Kirk ◽  
Kevin J. Gilmore ◽  
Charles L. Rice
Keyword(s):  
Motor Unit ◽  
Contractile Function ◽  
Age Groups ◽  
Biceps Femoris ◽  
Surface Emg ◽  
Muscle Group ◽  
Voluntary Activation ◽  
Discharge Rates ◽  
Age Related ◽  
Motor Unit Discharge

Despite the life-long importance for posture and locomotion, neuromuscular properties of the hamstrings muscle have not been explored with adult aging. The purpose of this study was to assess and compare age-related effects on contractile function, spinal motor neuron output expressed as motor unit (MU) discharge rates in the hamstrings of 11 young (26 ± 4 yr) and 10 old (80 ± 5 yr) men. Maximal voluntary isometric contractions (MVC), stimulated contractile properties, and surface and intramuscular electromyography (EMG) from submaximal to MVC were recorded in the biceps femoris (BF) and semimembranosus-semitendinosus (SS) muscles. MVC torque was ~50% less in the old with both age groups attaining ≥93% mean voluntary activation. Evoked twitches in the old were ~50% lower in amplitude and >150% longer in duration compared with those in the young. At successive voluntary contractions of 25, 50, and 100% MVC, MU discharge rates were up to 45% lower in old, with no differences in relative submaximal surface EMG between age groups. Furthermore, the old had significantly lower MU discharge rates in the SS at all contraction intensities compared with the BF muscle. Men in their 8th to 10th decades of life demonstrate substantially lower strength and MU discharge rates in this functionally important large lower limb muscle group, with greater age-related effect on discharge rates in the medial hamstrings. These findings, compared with those in other muscles studied, highlight that the neuromuscular properties of limb muscles, and indeed within functionally similar portions of a muscle group, are not all affected equally by the aging process. NEW & NOTEWORTHY In the hamstrings, we found that both contractile function and motor unit discharge rates across the range of voluntary intensities were lower in the old. The differences in discharge rates due to age were greater in the medial hamstrings muscle group compared with the lateral hamstrings. Compared with previous studies, these results highlight that not all muscles are affected equally by aging and there may be compartmental differences within functionally similar muscles.

Muscle CSA, Force Production, and Activation of Leg Extensors during Isometric and Dynamic Actions in Middle-Aged and Elderly Men and Women

1998 ◽  
Vol 6 (3) ◽  
pp. 232-247 ◽  
Author(s):  
Keijo Häkkinen ◽  
Markku Alen ◽  
Mauri Kallinen ◽  
Mikel Izquierdo ◽  
Kirsi Jokelainen ◽  
...  
Keyword(s):  
Isometric Force ◽  
Age Groups ◽  
Voluntary Activation ◽  
Maximal Strength ◽  
Power Performance ◽  
Time Duration ◽  
Cross Sectional ◽  
Men And Women ◽  
Age Related ◽  
Leg Extensors

Forty-two healthy men and women in two age groups (40 and 70 years) were examined for muscle cross-sectional area (CSA), maximal voluntary bilateral isometric force, force-time characteristics, maximal concentric 1 RM. and power performance of the leg extensors in a sitting position, squat jump, and standing long-jump. The results suggested that the decline in maximal strength with increasing age is related to the decline in muscle CSA; however, particularly in older women, the force/CSA ratio may also be lowered. Explosive force seems to decrease with increasing age even more than maximal strength. suggesting that muscle atrophy with aging is greater in fast-twitch fibers. The voluntary activation of the agonist and antagonist muscles seems to vary depending on the type of muscle action and/or velocity and time duration of the action in both age groups but to a greater extent in older people. There appears to be an age-related increase in antagonist co activation. especially in dynamic explosive movements.

Echocardiographic Findings and Cardiovascular Profile of the Very Old Indian Population

2020 ◽  
Vol 16 (2) ◽  
Author(s):  
Pramod Kumara ◽  
Rishav Bansal ◽  
Rakesh Yadav ◽  
Sada Nand Dwivedi ◽  
Prashun Chatterjee ◽  
...  
Keyword(s):  
Risk Factors ◽  
Older Adults ◽  
Cardiovascular Risk ◽  
Cardiovascular Diseases ◽  
Very Old ◽  
Old Adults ◽  
Non Invasive ◽  
Age Related ◽  
Echocardiographic Assessment ◽  
Age Related Changes

Background : Age-related changes in the cardiovascular system are significant, increasing the risk of cardiovascular diseases (CVDs) in older adults. CVDs are currently the leading cause of mortality among older Indian adults, yet very few studies are presently available evaluating the older adults for CVDs and risk factors. We aim to assess the very old adults for the prevalence of CVDs and risk factors using non-invasive assessment tools. Methodology : This hospital-based cross-sectional study included 200 adults aged 75 years and above, visiting a tertiary care hospital in India. They underwent routine clinical evaluation, a comprehensive geriatric assessment and detailed cardiovascular evaluation using non-invasive tools like echocardiography and blood investigations. Results : The overall prevalence of CVDs in this population was 76%. Among the cardiovascular risk factors, hyperhomocysteinemia was present in 83.5%, hypertension in 59.5%, dyslipidemia in 41.5%, sedentary lifestyle in 35%, and obesity in 30.5%, and Diabetes Mellitus in 24.5%. In echocardiographic assessment, valvular dysfunction was present in 33% of the population, though moderate to severe valvular disease was seen in 6.5%. Left ventricular diastolic dysfunction was seen in 81%, systolic dysfunction in 10% and pulmonary hypertension in 5% of the subjects. Conclusion : The very old adults had significant age-related changes in echocardiographic assessment, along with the high prevalence of cardiovascular diseases and risk factors. These findings should encourage physicians to screen the very old adults for cardiovascular risk factors and diseases, for their early identification and effective management.

Age-Related Differences Between Young and Old Adults: Effects of Advance Information on Task Switching

2020 ◽  
Vol 127 (6) ◽  
pp. 985-1014
Author(s):  
Wen-Pin Chang ◽  
I-Hsuan Shen ◽  
Chien-Pei Wen ◽  
Chia-Ling Chen
Keyword(s):  
Older Adults ◽  
Task Switching ◽  
Switch Cost ◽  
Age Groups ◽  
Reactive Control ◽  
Old Adults ◽  
Task Goal ◽  
Age Related ◽  
Significant Difference ◽  
Advance Information

In this study we investigated the effects of advance information on task switching in young and old adults, using two forms of advance information (memory-based and cue-based) and a no advance information task. We compared 19 healthy young and 19 healthy older adults in terms of their behavioral performance and neural correlates under these three task-switching paradigms. We observed a significant difference in mixing cost between the two age groups. There was no switch cost group difference on the memory-based and cue-based tasks, but older adults showed a larger switch cost than younger adults on the no advance information task. On evoked potential measures, there was no group effect in P3 cue-locked positivity; but there was, a frontal shift of the target-locked P3, indexed as reactive control, among older adults. We observed an increased target-locked P3 in the no-information paradigm compared with the cue-based and memory-based paradigms in both groups. Task cue facilitated advance preparation and proactive control under the cue-based paradigm in both groups. Age-related decline and difficulty in control processes required for task goal maintenance were apparent among the older adults.

scholarly journals Age Differences in the Required Coefficient of Friction During Level Walking Do Not Exist When Experimentally-Controlling Speed and Step Length

2014 ◽  
Vol 30 (4) ◽  
pp. 542-546 ◽  
Author(s):  
Dennis E. Anderson ◽  
Christopher T. Franck ◽  
Michael L. Madigan
Keyword(s):  
Older Adults ◽  
Age Differences ◽  
Coefficient Of Friction ◽  
Age Groups ◽  
Step Length ◽  
Age Difference ◽  
Age Related ◽  
Negative Effect ◽  
Independent Effects ◽  
Positive Effect

The effects of gait speed and step length on the required coefficient of friction (COF) confound the investigation of age-related differences in required COF. The goals of this study were to investigate whether age differences in required COF during self-selected gait persist when experimentally-controlling speed and step length, and to determine the independent effects of speed and step length on required COF. Ten young and 10 older healthy adults performed gait trials under five gait conditions: self-selected, slow and fast speeds without controlling step length, and slow and fast speeds while controlling step length. During self-selected gait, older adults walked with shorter step lengths and exhibited a lower required COF. Older adults also exhibited a lower required COF when walking at a controlled speed without controlling step length. When both age groups walked with the same speed and step length, no age difference in required COF was found. Thus, speed and step length can have a large influence on studies investigating age-related differences in required COF. It was also found that speed and step length have independent and opposite effects on required COF, with step length having a strong positive effect on required COF, and speed having a weaker negative effect.

Slight power output manipulations around the maximal lactate steady state have an impact on fatigue in females and males.

2021 ◽  
Author(s):  
Rafael de Almeida Azevedo ◽  
Jonas Forot ◽  
Danilo Iannetta ◽  
Martin J. MacInnis ◽  
Guillaume Y. Millet ◽  
...  
Keyword(s):  
Steady State ◽  
Power Output ◽  
Contractile Function ◽  
Femoral Nerve ◽  
Peak Torque ◽  
Knee Extensors ◽  
Time To Exhaustion ◽  
Maximal Lactate Steady State ◽  
Subsequent Performance ◽  
Single Twitch

Neuromuscular fatigue (NMF) and exercise performance are affected by exercise intensity and sex differences. However, whether slight changes in power output (PO) below and above the maximal lactate steady-state (MLSS) impact NMF and subsequent performance (time to exhaustion, TTE) is unknown. Purpose: This study compared NMF and TTE in females and males in response to exercise performed at MLSS, 10 W below (MLSS-10) and above (MLSS+10). Methods: Twenty participants (9 females) performed three 30-min constant-PO exercise bouts followed (1 min delay) by a TTE at 80% of the peak-PO. NMF was characterized by isometric maximal voluntary contractions (IMVC) and femoral nerve electrical stimulation of knee extensors [e.g. peak torque of potentiated high-frequency (Db100) and single twitch (TwPt)] before and immediately after the constant-PO and TTE bouts. Results: IMVC declined less after MLSS-10 (-18±10%) compared to MLSS (-26±14%) and MLSS+10 (-31±11%) (all p<0.05), and the Db100 decline was greater after MLSS+10 (-24±14%) compared to the other intensities (MLSS-10: -15±9%; MLSS: -18±11%) (all p<0.05). Females showed smaller reductions in IMVC and TwPt compared to males after constant-PO bouts (all p<0.05), this difference being not dependant on intensity. TTE was negatively impacted by increasing the PO in the constant-PO (p<0.001), with no differences in end-exercise NMF (p>0.05). Conclusion: Slight changes in PO around MLSS elicited great changes in the reduction of maximal voluntary force and impairments in contractile function. Although NMF was lower in females compared to males, the changes in PO around the MLSS impacted both sexes similarly.

scholarly journals The Gut Microbiome, Aging, and Longevity: A Systematic Review

Nutrients ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3759
Author(s):  
Varsha D. Badal ◽  
Eleonora D. Vaccariello ◽  
Emily R. Murray ◽  
Kasey E. Yu ◽  
Rob Knight ◽  
...  
Keyword(s):  
Systematic Review ◽  
Older Adults ◽  
Gut Microbiota ◽  
Gut Microbiome ◽  
Oldest Old ◽  
Amino Acid Synthesis ◽  
Old Adults ◽  
Age Related ◽  
Functional Features ◽  
Functional Pathways

Aging is determined by complex interactions among genetic and environmental factors. Increasing evidence suggests that the gut microbiome lies at the core of many age-associated changes, including immune system dysregulation and susceptibility to diseases. The gut microbiota undergoes extensive changes across the lifespan, and age-related processes may influence the gut microbiota and its related metabolic alterations. The aim of this systematic review was to summarize the current literature on aging-associated alterations in diversity, composition, and functional features of the gut microbiota. We identified 27 empirical human studies of normal and successful aging suitable for inclusion. Alpha diversity of microbial taxa, functional pathways, and metabolites was higher in older adults, particularly among the oldest-old adults, compared to younger individuals. Beta diversity distances significantly differed across various developmental stages and were different even between oldest-old and younger-old adults. Differences in taxonomic composition and functional potential varied across studies, but Akkermansia was most consistently reported to be relatively more abundant with aging, whereas Faecalibacterium, Bacteroidaceae, and Lachnospiraceae were relatively reduced. Older adults have reduced pathways related to carbohydrate metabolism and amino acid synthesis; however, oldest-old adults exhibited functional differences that distinguished their microbiota from that of young-old adults, such as greater potential for short-chain fatty acid production and increased butyrate derivatives. Although a definitive interpretation is limited by the cross-sectional design of published reports, we integrated findings of microbial composition and downstream functional pathways and metabolites, offering possible explanations regarding age-related processes.

scholarly journals Advanced Aging Enhances the Positivity Effect in Memory: Due to Cognitive Control or Age-Related Decline in Emotional Processing?

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Michiko Sakaki ◽  
Jasmine A. L. Raw ◽  
Jamie Findlay ◽  
Mariel Thottam
Keyword(s):  
Older Adults ◽  
Cognitive Control ◽  
Emotional Processing ◽  
Aging Brain ◽  
Control Mechanisms ◽  
Younger Adults ◽  
Positivity Effect ◽  
Old Adults ◽  
Age Related ◽  
Conditioned Responses

Older adults typically remember more positive than negative information compared to their younger counterparts; a phenomenon referred to as the ‘positivity effect.’ According to the socioemotional selectivity theory (SST), the positivity effect derives from the age-related motivational shift towards attaining emotionally meaningful goals which become more important as the perception of future time becomes more limited. Cognitive control mechanisms are critical in achieving such goals and therefore SST predicts that the positivity effect is associated with preserved cognitive control mechanisms in older adults. In contrast, the aging-brain model suggests that the positivity effect is driven by an age-related decline in the amygdala which is responsible for emotional processing and emotional learning. The aim of the current research was to address whether the age-related positivity effect is associated with cognitive control or impaired emotional processing associated with aging. We included older old adults, younger old adults and younger adults and tested their memory for emotional stimuli, cognitive control and amygdala-dependent fear conditioned responses. Consistent with prior research, older adults, relative to younger adults, demonstrate better memory for positive over negative images. We further found that within a group of older adults, the positivity effect increases as a function of age, such that older old adults demonstrated a greater positivity effect compared to younger older adults. Furthermore, the positivity effect in older old adults was associated with preserved cognitive control, supporting the prediction of SST. Contrary to the prediction of the aging-brain model, participants across all groups demonstrated similar enhanced skin conductance responses to fear conditioned stimuli – responses known to rely on the amygdala. Our results support SST and suggest that the positivity effect in older adults is achieved by the preserved cognitive control mechanisms and is not a reflection of the impaired emotional function associated with age.

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