Physiology of physical inactivity, sedentary behaviours and non-exercise activity: insights from the space bedrest model

Associations between Physical Activity Frequency in Leisure Time and Subjective Cognitive Limitations in Middle-Aged Spanish Adults: A Cross-Sectional Study

There is a global ageing of the world's population. Ageing is associated with multiple pathologies, reductions in physical activity, and losses in cognitive function. This study aimed to analyse the associations between the frequency of leisure-time physical activity (PAF) in middle-aged Spaniards and subjective cognitive limitations (SCLs): self-reported problems for remembering or concentrating (data extracted from the 2017 National Health Survey and the 2020 European Health Survey in Spain). Furthermore, the study aimed to evaluate risk factors that could be related to a higher probability of developing SCLs. This was a cross-sectional study with 15,866 middle-aged Spaniards. The associations between FAP and SCLs were analysed using chi-square. Also, the risk factors for SCLs were evaluated using binary multiple logistic regression. The median age of participants was 55 years, with 49% men and 51% women. Associations were found between PAF and SCLs (p < 0.001). The highest prevalence of SCLs was found in physically inactive people and the lowest in very active people (13.7% vs. 5.8%, p < 0.05), and people with SCLs had a higher prevalence of inactivity than those without SCLs (47.2% vs. 33.8%, p < 0.05). Physical inactivity, low educational level, low social class, and being female were the main risk factors for SCLs. Among the actions to prevent cognitive limitations, as well as interventions in people with cognitive limitations, it would be advisable to include physical activity programmes, both as a preventive measure to delay cognitive limitations and to reduce the risk of other pathologies in people who already have them.

Effects of different lower limb strengthening protocols on muscle activity, strength and power in sedentary and physically inactive subjects: a systematic review

Introduction

The purpose of this systematic review was: a) to determine the quality of evidence from studies assessing the effects of different lower limb strengthening protocols on muscle activity, strength, and power in sedentary and/or physically inactive subjects; and b) to determine the effectiveness of lower extremity strengthening protocols on muscle activity, strength, and power in sedentary and/or physically inactive subjects. Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) statements were followed using keywords associated with strength training, lower limb, sedentary, and physical inactivity. Four databases were used: Medline via PubMed, Web of Science, Scopus and SPORTDiscus. Methodological quality was assessed using the PEDro scale. A total of 164 articles were retrieved, six included in this review. Four studies were classified as fair methodological quality, and two were considered of good methodological quality. Due to the heterogeneity in methodological aspects and the limited number of articles including the variables under study, it was not possible to establish a measure of effectiveness of lower limb strengthening protocols on muscle activity, strength, or power. In conclusion, strength training in the lower limb seems to improve the levels of strength, power, and muscular activity in sedentary subjects. However, due to the limited number of articles, methodological variability, and training methods used, it is necessary to conduct new studies that control these variables.

Attitude and influencing factors on exercise in patients with moderately to severely active inflammatory bowel disease: a qualitative study

OBJECTIVES

To explore the attitudes towards exercise, factors influencing exercise and exercise-related needs of patients with moderately to severely active inflammatory bowel disease.

DESIGN

A qualitative phenomenological research.

SETTING

The study was conducted at a comprehensive tertiary hospital in Suzhou, China, which is a secondary care facility.

PARTICIPANTS

The study included 17 participants who met specific inclusion criteria: aged between 16 and 70 years, diagnosed with inflammatory bowel disease and in a state of moderate to severe disease activity. Participants were required to be capable of clear self-expression and provide voluntary consent. Exclusion criteria included the presence of cancer or severe physical illness, cognitive impairment or mental illness.

INTERVENTIONS

Semistructured interviews were used to collect data.

RESULTS

The exercise experiences of participants with moderate to severe inflammatory bowel disease yielded three themes: attitudes towards exercise, factors influencing exercise and exercise-related needs.

CONCLUSION

The majority of participants had negative attitudes towards exercise during periods of moderate to severe activity, largely influenced by disease activity, symptom management, inadequate knowledge of exercise and uncertainty about the value of exercise. Of particular note, professional guidance was generally recognised as stimulating a willingness to exercise positively, and participants demonstrated a strong need for professional guidance. Therefore, it is recommended that clear exercise guidelines for inflammatory bowel disease be constructed to ensure that patients receive safe and effective guidance to develop a healthy lifestyle in order to maximise the benefits of exercise.

The impact of 60 days of -6° head down tilt bed rest on mitochondrial content, respiration and regulators of mitochondrial dynamics

It is unclear how skeletal muscle metabolism and mitochondrial function adapt to long duration bed rest and whether changes can be prevented by nutritional intervention. The present study aimed (1) to assess the effect of prolonged bed rest on skeletal muscle mitochondrial function and dynamics and (2) to determine whether micronutrient supplementation would mitigate the adverse metabolic effect of bed rest. Participants were maintained in energy balance throughout 60 days of bed rest with micronutrient supplementation (INT) (body mass index: 23.747 ± 1.877 kg m-2 ; 34.80 ± 7.451 years; n = 10) or without (control) (body mass index: 24.087 ± 2.088 kg m-2 ; 33.50 ± 8.541 years; n = 10). Indirect calorimetry and dual-energy x-ray absorptiometry were used for measures of energy expenditure, exercise capacity and body composition. Mitochondrial respiration was determined by high-resolution respirometry in permeabilized muscle fibre bundles from vastus lateralis biopsies. Protein and mRNA analysis further examined the metabolic changes relating to regulators of mitochondrial dynamics induced by bed rest. INT was not sufficient in preserving whole body metabolic changes conducive of a decrease in body mass, fat-free mass and exercise capacity within both groups. Mitochondrial respiration, OPA1 and Drp1 protein expression decreased with bed rest, with an increase pDrp1s616 . This reduction in mitochondrial respiration was explained through an observed decrease in mitochondrial content (mtDNA:nDNA). Changes in regulators of mitochondrial dynamics indicate an increase in mitochondrial fission driven by a decrease in inner mitochondrial membrane fusion (OPA1) and increased pDrp1s616 . KEY POINTS: Sixty days of -6° head down tilt bed rest leads to significant changes in body composition, exercise capacity and whole-body substrate metabolism. Micronutrient supplementation throughout bed rest did not preserve whole body metabolic changes. Bed rest results in a decrease in skeletal muscle mitochondrial respiratory capacity, mainly as a result of an observed decrease in mitochondrial content. Prolonged bed rest ensues changes in key regulators of mitochondrial dynamics. OPA1 and Drp1 are significantly reduced, with an increase in pDrp1s616 following bed rest indicative of an increase in mitochondrial fission. Given the reduction in mitochondrial content following 60 days of bed rest, the maintenance of regulators of mitophagy in line with the increase in regulators of mitochondrial fission may act to maintain mitochondrial respiration to meet energy demands.

Indicators of LPO and Antioxidant Protection in Rats During Long-Term Restriction of Motor Activity

This article presents a comprehensive study of the parameters of LPO (concentrations of malondialdehyde, diene conjugates, and intensity of chemiluminescence) and antioxidant defense (concentrations of α-tocopherol, ceruloplasmin, total antioxidant activity, antiradical activity, and activities of antioxidant enzymes - superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase) in blood plasma and erythrocytes of white male rats during restriction of motor activity up to 28 days. The patterns of changes in oxidative balance in hypokinesia in the form of intensification of LPO processes against the background of depletion of resources of antioxidant defense with maximum manifestation on days 14-21 of the experiment were revealed.

Effects of recreational small-sided games from different team sports on the improvement of aerobic fitness in youth sedentary populations: A systematic review

Aerobic fitness is a critical aspect of overall health and well-being, essential for maintaining a high quality of life. Unfortunately, sedentary behavior has been on the rise among young adults, and this has had a negative impact on their aerobic fitness levels. Therefore, it is crucial to identify enjoyable physical exercise training programs that can play a pivotal role in improving aerobic fitness. The objective of this study was to systematically review the experimental studies concerning the impact of small-sided games (SSGs) training programs, implemented across various team sports, on the enhancement of aerobic fitness in a youth sedentary population. A literature search was conducted in PubMed, Scopus, and the Web of Science on August 01, 2023. Our eligibility criteria focused on studies involving sedentary youth populations (aged <18 years) as the target population. These studies needed to incorporate interventions based on SSGs as the intervention of interest, comparing them to passive or control groups as the comparator. The primary outcomes of interest were related to maximal oxygen uptake (VO2max), assessed either directly or indirectly, or the results of field-based cardiorespiratory tests. We specifically considered two- or multi-arm randomized controlled studies as the study design of interest. Out of the initial pool of 1980 studies, we reviewed 38 full-text articles, ultimately selecting and analyzing 13 studies for inclusion in our review. Among the studies included, a total of 1281 participants were enrolled in SSG-based interventions, while 744 participants acted as part of the control groups. Regarding the impact on VO2max, the six studies that investigated this outcome showed varying improvements, ranging from 2.2 % to 31.3 % when participants were exposed to SSGs. In terms of the outcome related to endurance performance in field-based tests, the eight studies that examined this aspect found that participants exposed to SSGs showed improvements ranging from 0.1 % to 79.8 %. In conclusion, this systematic review suggests that SSG-based interventions conducted among sedentary youth populations can play a positive role in improving their aerobic fitness. This improvement in aerobic fitness can have potential positive impacts on their overall health and quality of life.

Sex Difference in the Association Between Sedentary Behavior and Sleep Quality: A Longitudinal Study Among Older Adults in Rural China

OBJECTIVES

Sleep quality plays a vital role in maintaining health in older adults. Sedentary behavior may be a risk factor for poor sleep quality in older adults. This study aimed to explore the relationship between sedentary behavior and sleep quality among older adults in rural China and determine whether there is a sex difference in this association.

DESIGN

A longitudinal design. The data used in this study were obtained from the Shandong Rural Elderly Health Cohort (wave 1: 2019, wave 2: 2020).

SETTING AND PARTICIPANTS

Data were from 2731 individuals aged ≥60 years from rural areas in China.

METHODS

Sleep quality was assessed using the Pittsburgh Sleep Quality Index. Sedentary behavior and control variables were measured using self-reported questions. Multivariable logistic regression and generalized estimating equations were used to assess the associations.

RESULTS

After full adjustment, the association between sedentary behavior and poor sleep quality was statistically significant [odds ratio (OR) 1.49, 95% CI 1.20-1.85]. Specifically, a longer sedentary time was associated with worse subjective sleep quality, less sleep latency, and lower habitual sleep efficiency (OR 1.39-1.58). A significant association was observed in women but not men.

CONCLUSIONS AND IMPLICATIONS

Older adults who spend more time engaging in sedentary activities have poorer sleep quality and more sleep problems. Prolonged sedentary time is more detrimentally associated with poor sleep quality in women than men. There is a need for tailored exercise prescriptions and guidelines to stimulate older adults of different sexes to change their sedentary behavior, which may improve sleep quality in older adults.

Physiology of sedentary behavior

Sedentary behaviors (SB) are characterized by low energy expenditure while in a sitting or reclining posture. Evidence relevant to understanding the physiology of SB can be derived from studies employing several experimental models: bed rest, immobilization, reduced step count, and reducing/interrupting prolonged SB. We examine the relevant physiological evidence relating to body weight and energy balance, intermediary metabolism, cardiovascular and respiratory systems, the musculoskeletal system, the central nervous system, and immunity and inflammatory responses. Excessive and prolonged SB can lead to insulin resistance, vascular dysfunction, shift in substrate use toward carbohydrate oxidation, shift in muscle fiber from oxidative to glycolytic type, reduced cardiorespiratory fitness, loss of muscle mass and strength and bone mass, and increased total body fat mass and visceral fat depot, blood lipid concentrations, and inflammation. Despite marked differences across individual studies, longer term interventions aimed at reducing/interrupting SB have resulted in small, albeit marginally clinically meaningful, benefits on body weight, waist circumference, percent body fat, fasting glucose, insulin, HbA1c and HDL concentrations, systolic blood pressure, and vascular function in adults and older adults. There is more limited evidence for other health-related outcomes and physiological systems and for children and adolescents. Future research should focus on the investigation of molecular and cellular mechanisms underpinning adaptations to increasing and reducing/interrupting SB and the necessary changes in SB and physical activity to impact physiological systems and overall health in diverse population groups.

Sedentary Time Is Independently Related to Adipose Tissue Insulin Resistance in Adults With or at Risk of Type 2 Diabetes

INTRODUCTION

This cross-sectional study examined associations of device-measured sedentary time and moderate-to-vigorous physical activity (MVPA) with adipose tissue insulin resistance in people with or at high risk of type 2 diabetes (T2DM).

METHOD

Data were combined from six previous experimental studies (within our group) involving patients with T2DM or primary risk factors (median (interquartile range) age, 66.2 (66.0-70.8) yr; body mass index (BMI), 31.1 (28.0-34.4) kg·m -2 ; 62% male; n = 179). Adipose tissue insulin resistance was calculated as the product of fasted circulating insulin and nonesterified fatty acids (ADIPO-IR), whereas sedentary time and MVPA were determined from wrist-worn accelerometery. Generalized linear models examined associations of sedentary time and MVPA with ADIPO-IR with interaction terms added to explore the moderating influence of ethnicity (White European vs South Asian), BMI, age, and sex.

RESULTS

In finally adjusted models, sedentary time was positively associated with ADIPO-IR, with every 30 min of sedentary time associated with a 1.80-unit (95% confidence interval, 0.51-3.06; P = 0.006) higher ADIPO-IR. This relationship strengthened as BMI increased ( β = 3.48 (95% confidence interval, 1.50-5.46), P = 0.005 in the upper BMI tertile (≥33.2 kg·m -2 )). MVPA was unrelated to ADIPO-IR. These results were consistent in sensitivity analyses that excluded participants taking statins and/or metformin ( n = 126) and when separated into the participants with T2DM ( n = 32) and those at high risk ( n = 147).

CONCLUSIONS

Sedentary time is positively related to adipose tissue insulin sensitivity in people with or at high risk of T2DM. This relationship strengthens as BMI increases and may help explain established relationships between greater sedentary time, ectopic lipid, and hyperglycemia.

New frontiers in the measurement of energy metabolism

This perspective highlights three key areas of current and future energy metabolism research: intergenerational health, climate change, and interplanetary exploration. We describe the recent advances in determining estimated energy requirements for a large subset of the general population using the gold standard method for free-living total daily energy expenditure estimates, the doubly labeled water method. The global rise in overweight and obesity demands particular attention to energy requirements in pregnancy and early life, as accumulating evidence contributes to our understanding of intergenerational health transmission and the potential for epigenetic programming in utero. We also acknowledge some gaps in necessary guidelines and understandings of energy requirements for underrepresented populations (i.e., individuals from low and middle-income countries) or those who undergo major physiological changes in new environment (e.g., astronauts). The rising prevalence of excess weight gain, together with climate change, cumulate into a global syndemic exposing vulnerable populations to both malnutrition and the effects of unpredictable and severe weather events, emphasizing the need for varied energetic data accounting for rapid physiological and socioeconomic changes. Finally, we relate how specific estimated energy requirements are needed to account for the energetic challenges specific to extended space travel and ensure the success of interplanetary exploration.

Habitual physical activity and sedentary behavior as predictors of dynapenia in older adults: a cross-sectional study

BACKGROUND

Dynapenia is a risk factor of mortality. Therefore, the development of low-cost and easy-to-apply tools is essential to optimize the health surveillance actions of older people.

OBJECTIVES

To compare the time spent on habitual physical activity (HPA) and sedentary behavior (SB) among dynapenic and non-dynapenic older adults and ascertain the predictive ability of these behaviors on outcome.

DESIGN AND SETTING

A cross-sectional population epidemiological survey was conducted involving 208 older adults.

METHODS

HPA and SB were quantified using the International Physical Activity Questionnaire, and dynapenia was identified by handgrip strength (women: 18.37 kgf; men: 26.75 kgf).

RESULTS

The prevalence was 24.50%. In both sexes, dynapenic individuals reported a HPA median time of 70.00 minutes/week (min/wk), while non-dynapenic women and men reported HPA median times of 240.00 and 280.00 min/wk, respectively (P < 0.05). For SB among dynapenic individuals, a median of 388.75 min/day was observed in women and 428.57 min/d in men. In contrast, non-dynapenic women and men had 291.42 and 274.28 min/day in SB (P < 0.05), respectively. The best cutoff HPA to discriminate the outcome was 150.00 min/wk in women (sensitivity: 73.30%; specificity: 60.67%) and 140.00 min/wk in men (sensitivity, 71.43%; specificity, 61.54%). The best cutoff SB was 381.43 min/day in women (sensitivity, 53.30%; specificity, 84.80%) and 351.43 min/day in men (sensitivity, 71.43%; specificity, 73.85%).

CONCLUSION

Older individuals with dynapenia spent less time on HPA and more time in SB. Furthermore, HPA was found to be a better discriminator of dynapenic individuals, and SB better discriminated non-dynapenic individuals.

Sociodemographic, Behavioural, and Health Factors Associated with Sedentary Behaviour in Community-Dwelling Older Adults: A Nationwide Cross-Sectional Study

Few studies have focused on factors associated with sedentary behaviour among older Asian adults. This study aimed to identify factors independently associated with prolonged sedentary times in Korean older adults. We included 8273 community-dwelling older adults aged ≥65 years who participated in the Korean National Health and Nutrition Examination Survey. Self-reported sedentary times were assessed via the Global Physical Activity Questionnaire, and sedentary times of ≥420 min/day were considered 'long'. Complex-sample multivariable-adjusted logistic regression analyses were conducted to investigate the factors associated with long sedentary times. Among the participants, 4610 (55.72%) had long sedentary times that were associated with advanced age (odds ratio [OR], 2.49; 95% confidence interval [CI], 2.05-3.01), female sex (OR, 1.32; 95% CI, 1.11-1.57), unemployment (OR, 1.23; 95% CI, 1.09-1.38), living alone (OR, 1.24; 95% CI, 1.08-1.43), urban residence (OR, 1.35; 95% CI, 1.14-1.61), and insufficient aerobic exercise (OR, 1.80; 95% CI, 1.60-2.02). Among health factors, obesity (OR, 1.27; 95% CI, 1.12-1.45), diabetes (OR, 1.17; 95% CI, 1.04-1.32), cardiovascular diseases (OR, 1.30; 95% CI, 1.11-1.52), and arthritis (OR, 1.26; 95% CI, 1.11-1.43) had positive associations with long sedentary times. A tailored approach that considered various sociodemographic, behavioural, and health factors is needed to reduce sedentary behaviour in this population.

Recreational Soccer Training Effects on Pediatric Populations Physical Fitness and Health: A Systematic Review

This systematic review analyzed the effects of recreational soccer programs on physical fitness and health-related outcomes in youth populations. Studies were sought in the following databases: (i) PubMed, (ii) Scopus, (iii) SPORTDiscus, and (iv) Web of Science. The eligibility criteria included (1) population: youth (<18 years old) populations with no restrictions on sex or health condition; (2) intervention: exposure to a recreational soccer training program of at least four weeks duration; (3) comparator: a passive or active control group not exposed to a recreational soccer training program; (4) outcomes: physical fitness (e.g., aerobic, strength, speed, and change-of-direction) or health-related measures (e.g., body composition, blood pressure, heart rate variability, and biomarkers); (5) study design: a randomized parallel group design. The search was conducted on 6 September 2022 with no restrictions as to date or language. The risk of bias was assessed using the PEDro scale for randomized controlled studies. From a pool of 37,235 potentially relevant articles, 17 were eligible for inclusion in this review. Most of the experimental studies revealed the beneficial effects of recreational soccer for improving aerobic fitness and its benefits in terms of blood pressure and heart-rate markers. However, body composition was not significantly improved by recreational soccer. The main results revealed that recreational soccer training programs that are implemented twice a week could improve the generality of physical fitness parameters and beneficially impact cardiovascular health and biomarkers. Thus, recreational soccer meets the conditions for being included in the physical education curriculum as a good strategy for the benefit of the general health of children and young people.

OPA1 regulation of mitochondrial dynamics in skeletal and cardiac muscle

The mitochondria are double-membrane organelles integral for energy metabolism. Mitochondrial dynamics is regulated by inner and outer mitochondrial membrane (IMM and OMM) proteins, which promote fission and fusion. Optic atrophy 1 (OPA1) regulates IMM fusion, prevents apoptosis, and is a key regulator of morphological change in skeletal and cardiac muscle physiology and pathophysiology. OPA1 fuses the inner membranes of adjacent mitochondria, allowing for an increase in oxidative phosphorylation (OXPHOS). Considering the importance of energy metabolism in whole-body physiology, OPA1 and its regulators have been proposed as novel targets for the treatment of skeletal muscle atrophy and heart failure. Here, we review the role and regulation of OPA1 in skeletal muscle and cardiac pathophysiology, epitomizing its critical role in the cell.

Effects of long-term simulated microgravity on liver metabolism in rhesus macaques

The liver is an essential multifunctional organ and constantly communicates with nearly all the tissues in the body. Spaceflight or simulated microgravity has a significant impact on the livers of rodent models, including lipid accumulation and inflammatory cell infiltration. Whether similar liver lipotoxicity could occur in humans is not known, even though altered circulating cholesterol profile has been reported in astronauts. Using a 42-day head-down bed rest (HDBR) model in rhesus macaques, the present study investigated whether simulated microgravity alters the liver of non-human primates at the transcriptome and metabolome levels. Its association with stress and intestinal changes was also explored. Compared to the controls, the HDBR monkeys showed mild liver injury, elevated ANGPTL3 level in the plasma, and accumulation of fat vacuoles and inflammatory cells in the liver. Altered transcriptome signatures with up-regulation of genes in lipid metabolisms and down-regulation of genes in innate immune defense were also found in HDBR group-derived liver samples. The metabolic profiling of the liver revealed mildly disturbed fatty acid metabolism in the liver of HDBR monkeys. The intestinal dysbiosis, its associated endotoxemia and changes in the composition of bile acids, and elevated stress hormone in HDBR monkeys may contribute to the altered lipid metabolisms in the liver. These data indicate that liver metabolic functions and gut-liver axis should be closely monitored in prolonged spaceflight to facilitate strategy design to improve and maintain metabolic homeostasis.

As diferentes tipologias do comportamento sedentário estão associadas ao histórico de problemas no sono em idosos comunitários?

Alterações no sono são comuns em idosos e alguns fatores de risco podem agravar essa condição. Entender a associação do comportamento sedentário com o histórico de problemas de sono poderá auxiliar na elaboração de programas de intervenção. Verificar a associação entre tipologias do comportamento sedentário e histórico de problemas no sono em idosos comunitários brasileiros. Estudo transversal, com dados de 43.554 idosos participantes da Pesquisa Nacional de Saúde (PNS), de 2019. As tipologias do comportamento sedentário foram avaliadas por: (1) tempo assistindo televisão; (2) atividades de lazer; e (3) tempo despendido total (televisão + lazer). O comportamento sedentário foi categorizado em < 3; 3-6 e > 6 horas/dia. O desfecho foi histórico de problemas de sono (dificuldade para adormecer, acordar frequentemente à noite ou dormir mais do que de costume) avaliados por meio do autorrelato nos últimos 15 dias. As associações foram verificadas pela regressão logística multivariável. Idosos que permaneceram tempo > 6 horas/dia em comportamento sedentário assistindo televisão tiveram 13% (OR = 1,13; IC95%: 1,02; 1,26) maiores probabilidades de relatarem problemas de sono. Referente ao comportamento sedentário total, idosos que permaneceram entre 3-6 horas e mais do que 6 horas/dia apresentaram 13% (OR = 1,13; IC95%: 1,04; 1,22) e 11% (OR = 1,11; IC95%: 1,01; 1,23) maiores probabilidades de problemas de sono, respectivamente. Os idosos amostrados que relataram permanecer por períodos superiores a 6 horas por dia em comportamento sedentário assistindo à televisão e > 3 horas em comportamento sedentário total tiveram maiores chances de terem problemas no sono. Estes achados podem contribuir nas orientações sobre a necessidade de redução no comportamento sedentário em idosos.

The Effect of Obesity Class on the Energetics and Mechanics of Walking

Higher mass-normalized net energy cost of walking (NetC_w/kg) and mechanical pendular recovery are observed in obese compared to lean adults. This study aimed to investigate the effect of different classes of obesity on the energetics and mechanics of walking and to explore the relationships between body mass, NetC_w/kg and gait mechanics by using principal component analysis (PCA). NetC_w/kg and gait mechanics were computed in severely obese (SOG; n = 18, BMI = 40.1 ± 4.4 kg·m⁻²), moderately obese (MOG; n = 17, BMI = 32.2 ± 1.5 kg·m⁻²) and normal-weight (NWG; n = 13, BMI = 22.0 ± 1.5 kg·m⁻²) adults during five walking trials (0.56, 0.83, 1.11, 1.39, 1.67 m·s⁻¹) on an instrumented treadmill. NetC_w/kg was significantly higher in SOG compared to NWG (p = 0.019), with no significant difference between SOG and MOG (p = 0.14), nor between MOG and NWG (p = 0.27). Recovery was significantly higher in SOG than in NWG (p = 0.028), with no significant difference between SOG and MOG (p = 0.13), nor between MOG and NWG (p = 0.35). PCA models explained between 17.0% and 44.2% of the data variance. This study showed that: (1) obesity class influences the gait energetics and mechanics; (2) PCA was able to identify two components, showing that the obesity class is associated with lower walking efficiency and better pendulum-like characteristics.

The Effects of Reduced Physical Activity on the Lipid Profile in Patients with High Cardiovascular Risk during COVID-19 Lockdown

Background: The COVID-19 pandemic is a serious global health problem. In Italy, to limit the infections, the government ordered lockdown from March 2020. This measure, designed to contain the virus, led to serious limitations on the daily life of the individuals it affected, and in particular in the limitation of physical exercise. The aim of this study was to evaluate the effects of reduced physical activity on the lipid profile in patients with high cardiovascular risk. Methods: We enrolled 38 dyslipidemic patients, 56% male, with an age range of 44-62 years, considered to be at high cardiovascular risk. All patients were prescribed statin drug therapy (atorvastatin 40 mg) and a vigorous physical activity program four times a week, 1 h per session. In addition, a personalized Mediterranean diet was prescribed to all the patients. Total cholesterol, LDL, HDL and triglycerides were measured in patients at T0 before lockdown and at T1 during lockdown. Results: Data showed a significant increase (p < 0.01) in total cholesterol (+6,8%) and LDL (+15,8%). Furthermore, the analysis of the data revealed a reduction in HDL (-3%) and an increase in triglycerides (+3,2%), although both were not significant (p > 0.05). Conclusions: Our study showed that the reduction in physical activity during lockdown led to an increase in LDL levels, and therefore, in the risk of ischemic heart disease in dyslipidemic patients with high cardiovascular risk.