Effects of Exercise Dose and Detraining Duration on Mobility at Late Midlife: A Randomized Clinical Trial

Effect of exercise detraining in cognitive functions of older adults: A systematic review

OBJECTIVE

Provide a synthesis of the current literature about the effects of detraining on cognitive functions in older adults.

METHODS

The PICOS acronym strategy was performed in PubMed/MEDLINE, Web of Science, Cochrane Library and PsycINFO database. The Preferred Reporting Items for Systematic Review and Meta-Analyses statement had been followed in the present study, in which the search was conducted on October 2023. The study selection consisted in original articles including older adults, detraining after training exercise period, use of tests or scales to measure cognitive function. The Downs and Black checklist had been used to assess the studies quality. Sample characteristics, type of previous training, detraining period, cognitive functions measurements and main results were extracted by 2 investigators.

RESULTS

From 1927 studies, 12 studies were included, being 11 studies identified via systematic research, and 1 study by citation search. Older adults, ranged from 60 to 87 years old, were assessed after detraining. The cognitive functions most evaluated were global cognition and executive functions. One study evaluated both cognitive outcome and cerebral blood flow. Most of the studies demonstrated a decline in the cognitive function after detraining.

CONCLUSION

Exercise detraining period, ranging from 10 days to 16 weeks, can effect negatively the cognitive function in older adults.

Cognitive Performance following Single- or Multi-Session Exercise Intervention in Middle Age: A Systematic Review

BACKGROUND

Research in modifiable behaviors, like exercise, on risk for dementia is increasing. Although many studies focus on older adults, brain pathology for Alzheimer's Disease can begin in middle age, suggesting an ideal target for intervention.

METHODS

We conducted a systematic review from exercise intervention studies on cognitive function among healthy, middle-aged participants (45-65). We searched multiple databases (PubMed, PsycINFO, MEDLINE, Cochrane Central Register of Controlled Trials, Google Scholar) for studies using standard, validated, neuropsychological measures following either single- or multi-session interventions in cognitively-unimpaired, middle-aged adults.

RESULTS

We identified 13 eligible studies. There was notable heterogeneity across studies, with varying design, measures, interventions, and results. Results from single-session studies showed improvement in response inhibition, while results for cognitive flexibility were mixed. No significant changes were found on measures of attention, working memory, or processing speed. Results from multi-session studies were more varied. Verbal memory was found to improve while performance on tests of attention and working memory, processing speed, and executive function were mixed.

CONCLUSION

Importantly, for both single-session and multi-session studies, there was no standard set of neuropsychological tests administered, making it more difficult to synthesize the findings into a single narrative. We end with a discussion on future directions and implementation.

A health behaviour pandemic: The COVID-19 pandemic has impacted the physical activity, sleep, and sedentary behaviour of already-struggling Canadians

Objectives

The Canadian 24-Hour Movement Guidelines (24HMG) provide evidence-based recommendations for health behaviours, including light physical activity, moderate-to-vigorous physical activity (MVPA), sedentary behaviour (SB), sleep, and muscle strengthening activities. These behaviours likely changed as a result of public health measures implemented throughout the COVID-19 pandemic. We aimed to understand how Canadians' health behaviours changed during the pandemic.

Methods

We conducted a nationwide survey asking Canadians aged 18-64 to report their health behaviours according to the 24HMG at three timepoints: 1) immediately prior to the pandemic, 2) the most restricted timepoint of the pandemic, and 3) more recently, in March 2022.

Results

We received 494 eligible responses from across Canada. Prior to the pandemic, only 7.7% of respondents were able to meet all 24HMG, which reduced to 3.8% during the most restricted phase of the pandemic (p < 0.01). During this timepoint, self-reported MVPA decreased by -21.9 ± 55.6 weekly minutes, muscle strengthening decreased by -0.34 ± 0.94 weekly sessions, and SB increased by 0.88 ± 2.04 daily hours (p < 0.00001 for all), with nonsignificant increases in nightly sleep. At the more recent March 2022 timepoint, mild recoveries were observed in all health behaviours, however remained significantly lower than baseline levels, with the exception of sleep, which decreased significantly (-0.18 ± 1.42 nightly hours, p = 0.005).

Conclusions

Unfavourable health behaviour changes among Canadians were observed throughout the COVID-19 pandemic, which increases the risk for acute and long-term health conditions. Improved education, infrastructure, and support from public and private sectors can reverse the negative risk factors that arise from these health behaviour changes, and can improve the culture of proactive health behaviours in Canada.

Age-related changes in gait biomechanics and their impact on the metabolic cost of walking: Report from a National Institute on Aging workshop

Changes in old age that contribute to the complex issue of an increased metabolic cost of walking (mass-specific energy cost per unit distance traveled) in older adults appear to center at least in part on changes in gait biomechanics. However, age-related changes in energy metabolism, neuromuscular function and connective tissue properties also likely contribute to this problem, of which the consequences are poor mobility and increased risk of inactivity-related disease and disability. The U.S. National Institute on Aging convened a workshop in September 2021 with an interdisciplinary group of scientists to address the gaps in research related to the mechanisms and consequences of changes in mobility in old age. The goal of the workshop was to identify promising ways to move the field forward toward improving gait performance, decreasing energy cost, and enhancing mobility for older adults. This report summarizes the workshop and brings multidisciplinary insight into the known and potential causes and consequences of age-related changes in gait biomechanics. We highlight how gait mechanics and energy cost change with aging, the potential neuromuscular mechanisms and role of connective tissue in these changes, and cutting-edge interventions and technologies that may be used to measure and improve gait and mobility in older adults. Key gaps in the literature that warrant targeted research in the future are identified and discussed.

Issues on Trainability

Trainability is an adaptive response to given exercise loads and must be localized to the targeted physiological function since exercise-induced acute and chronic adaptations are systemic. Lack of adaptation or moderate level of adaptation in one organ or one physiological function would not mean that other organs or functions would not benefit from exercise training. The most beneficial training load could easily be different for skeletal muscle, brain, the gastro-intestinal track, or the immune systems. Hence, the term of non-responders should be used with caution and just referred to a given organ, cell type, molecular signaling, or function. The present paper aims to highlight some, certainly not all, issues on trainability especially related to muscle and cardiovascular system. The specificity of trainability and the systemic nature of exercise-induced adaptation are discussed, and the paper aims to provide suggestions on how to improve performance when faced with non-responders.

Multicomponent Exercise Program for Improvement of Functional Capacity and Lipidic Profile of Older Women with High Cholesterol and High Triglycerides

Background: Physical inactivity is a primary cause of most chronic diseases. In addition, the negative effects of aging, physical inactivity and dyslipidemia are risk factors for cardiovascular diseases of older women. Exercise is considered fundamental for the treatment and prevention due to the benefits in the health of this population, but detraining periods after exercise can reverse them. Multicomponent exercise (ME) is a combined method of aerobic and resistance training that can improve the lipidic profile of older women with high cholesterol and triglycerides. Methods: Seventeen older women (EG: 65.3 ± 4.7 years, 1.52 ± 4.12 m) followed a supervised ME program of nine months and three months of detraining (DT), and fifteen older women (CG: 66.4 ± 5.2 years, 1.54 ± 5.58 cm) continued their daily routine, without exercise. Total cholesterol (TC), triglycerides (TG), blood glucose (GL) and functional capacity (FC) were evaluated at the beginning and at the end of the program and after three months of DT. Results: ME program improved (p < 0.05) lipidic profile: GL (−15.6%), TC (−15.3%), TG (−19.3%) and FC: agility (−13.3%), lower body strength (27.78%), upper body strength (26.3%), cardiorespiratory capacity (11.2%), lower body flexibility (66.67%) and upper body flexibility (85.72%). DT declined the lipidic profile and FC (p < 0.05). Conclusion: Lipidic profile and functional capacity can be improved with nine months of ME. Besides the negative effects of DT, three months were not enough to reverse the benefits of exercise in older women with high values of TG and TC.

Can Exercise Help Regulate Blood Pressure and Improve Functional Capacity of Older Women with Hypertension against the Deleterious Effects of Physical Inactivity?

BACKGROUND

Sedentarism and inactivity are risk factors for the development of hypertension. Thus, the prevention of the natural process of biological and physiological aging of older women through physical exercise results in higher benefits in preventing cardiovascular diseases and can be a key factor for its treatment. Multicomponent exercise (METP) is a training method that may help older women with hypertension by improving their quality of life and their response to treatment.

METHODS

Twenty-eight older Caucasian women with hypertension (66.7 ± 5.3 years, 1.59 ± 0.11 m) performed a supervised METP program of nine months followed by three months of detraining (DT), and seventeen older women (68.2 ± 4.7 years, 1.57 ± 0.16 cm) with hypertension maintained their daily routine, without exercise. Blood pressure (BP), resting heart rate, and functional capacity (FC) were evaluated at the beginning and at the end of the program, and after three months of DT.

RESULTS

The ME program improved (p < 0.05) systolic BP (-5.37%), diastolic BP (-5.67%), resting heart rate (-7.8%), agility (9.8%), lower body strength (27.8%), upper body strength (10.0%), and cardiorespiratory capacity (8.6%). BP and FC deteriorated after the DT period (p < 0.05).

CONCLUSION

Nine months of multicomponent exercise were sufficient to improve functional capacity and promote benefits in blood pressure, although was not sufficient to allow BP to reach the normal values of older women. The three month DT period without exercise caused the reversal of BP improvements but maintained the functional capacity of older women.