Low-intensity Exercise Research Articles

Low-Intensity Resistance Exercise in Cardiac Rehabilitation: A Narrative Review of Mechanistic Evidence and Clinical Implications

Cardiac rehabilitation, a multi-component intervention designed to mitigate the impact of cardiovascular disease, often underutilises low-intensity resistance exercise despite its potential benefits. This narrative review critically examines the mechanistic and clinical evidence supporting the incorporation of low-intensity resistance exercise into cardiac rehabilitation programmes. Research indicates that low-intensity resistance exercise induces hypertrophic adaptations by maximising muscle fibre activation through the size principle, effectively recruiting larger motor units as it approaches maximal effort. This activation promotes adaptation in both type I and II muscle fibres, resulting in comparable increases in myofibrillar protein synthesis and phosphorylation of key signalling proteins when compared to high-intensity resistance exercise. Low-intensity resistance exercise provides equivalent improvements in muscular strength and hypertrophy compared to high-intensity protocols while addressing barriers to participation, such as concerns about safety and logistical challenges. By facilitating engagement through a more accessible exercise modality, low-intensity resistance exercise might improve adherence rates and patient outcomes in cardiac rehabilitation. Additionally, the ability of low-intensity resistance exercise to address sarcopenia and frailty syndrome, significant determinants of cardiovascular disease progression, can enhance the recovery and overall quality of life for patients. This review establishes evidence-based recommendations for the inclusion of low-intensity resistance exercise in cardiac rehabilitation, offering a promising pathway to enhance the effectiveness of these programmes.

Systemic hypoxia has a larger effect on reducing the external load at lower exercise intensity during heart rate clamped cycling.

The effects of acute hypoxic exposure on mechanical output and internal responses during cycling with heart rate (HR) clamped at lactate thresholds 1 and 2 (LT1 and LT2, respectively) were investigated. On separate days, 12 trained males cycled for 15min at a clamped HR corresponding to LT1 and LT2 under normoxic or hypoxic conditions (simulated altitude of ∼3500m and inspired oxygen fraction of 13.6%). Power output (PO), arterial oxygen saturation, ventilatory and perceptual responses were measured every 3min, with metabolic response assessed pre- and post-exercise. At LT1, PO was consistently lower in hypoxia compared to normoxia (p<0.01). At LT2, PO was not different between normoxia and hypoxia at 3 and 6min (both p>0.42) but was significantly lower in hypoxia at 9, 12 and 15min (all p<0.04). Overall, hypoxia induced a greater decrease in PO at LT1 (-33.3%±11.3%) than at LT2 (-18.0±14.7%) compared to normoxia. Ventilatory, perceptual and metabolic responses were influenced by exercise intensity (all p<0.01) but not environmental conditions (all p>0.17). A simulated altitude of ∼3500m is more effective in reducing cycling PO at LT1 than LT2 during HR clamped cycling while maintaining other internal loads. Therefore, normobaric hypoxia provides a greater benefit via a larger decrease in the mechanical constraints of exercise at lower exercise intensities.

Investigating the Influence of Limb Blood Flow on Contraction-Induced Muscle Growth and the Impact of that Growth on Changes in Maximal Strength.

Changes in skeletal muscle size may be affected by resting blood flow (e.g., nutrient delivery) and this change in size is a hypothesized mechanism for changes in strength. To determine: 1) whether the relationship between isometric training and muscle growth depends on baseline blood flow or is mediated by a change in blood flow and 2) whether muscle growth mediates changes in maximal isometric strength. 179 participants were randomized into: low-intensity isometric handgrip exercise (LI), low-intensity isometric handgrip exercise with blood flow restriction (LI-BFR), maximal handgrip exercise (MAX), and a non-exercise control (CONTROL). Muscle thickness, strength, and resting limb blood flow were measured before and after the six-week intervention. Baseline blood flow did not moderate training effects on muscle thickness changes (MTHchg) (p = 0.666), and moderated mediation tests were non-significant. Although the LI-BFR group showed a significant effect on MTHchg (p = 0.018), MTHchg was not significantly related to handgrip strength change (HGchg) (p = 0.281), suggesting no mediation of the training-to-strength effect by MTHchg. Both the LI-BFR (p = 0.004) and MAX (p < 0.001) groups exhibited positive direct effects on HGchg compared to CONTROL. Furthermore, there were no differences between training groups and CONTROL on blood flow change (BFchg), BFchg and MTHchg were not significantly related, and neither BFchg nor MTHchg predicted HGchg, providing no evidence for mediated pathways. Muscle growth may not have occurred to an extent that would require vascular adaptation. Training maximally induced the greatest strength adaptations but was seemingly not driven by muscle growth.

L-Arginine Supplementation Did Not Impact the Rapid Recovery of Cardiovascular and Autonomic Function Following Exercise in Physically Active Healthy Males: A Triple-Blind Randomised Placebo-Controlled Crossover Trial

Background and Aims: Post-exercise recovery strategies include massage, low-intensity active exercise, thermal contrast, hydration, and nutritional and herbal approaches. These strategies aim to accelerate recovery, enhance performance, and optimise the physical training process. L-arginine (L-ARG) is the physiological precursor of nitric oxide (NO), a crucial mediator of vasodilation and the inhibition of platelet aggregation. A previous study reported that L-ARG supplementation could significantly reduce the systolic blood pressure (SBP) and diastolic blood pressure (DBP). This study aimed to investigate the effects of L-ARG on autonomic and cardiovascular recovery immediately following submaximal exercise. Methods and Results: Thirty-two healthy individuals were subjected to two experimental protocols. The first protocol included 60 min of rest, a treadmill warm-up, and load increments until reaching 80% of their maximum HR. Before this protocol, the subjects consumed 3 g of starch (placebo protocol). The second protocol was identical, but the subjects consumed 3 g of L-ARG. Heart rate recovery (HRR), heart rate variability (HRV), and blood pressure (BP) responses were assessed. No significant differences in HRR were found (p = 0.944) regarding the root mean square of successive differences in the RR interval (RMSSD30) of HRV (p = 0.562) or in the BP responses (mean arterial pressure (MAP), p = 0.687; pulse pressure (PP), p = 0.929) between the protocols. Conclusions: L-ARG supplementation did not significantly alter immediate post-exercise autonomic recovery in healthy males.

Sleep Deprivation in Healthy Males Increases Muscle Afferents, Impairing Motor Preparation and Reducing Endurance.

Sleep deprivation (SD) reduces time to task failure during endurance exercises. The aim of our work was to study the effect of acute SD on the endurance of a skeletal hand muscle and to investigate cortical motor drive to muscle and perception of effort. Origin of the early exhaustion after SD might be insufficient cortical motor drive to muscle or motor inhibition because of excessive perception of effort. The supplementary motor area, the medial part of the premotor cortex, links the motor and sensory cortexes, prepares for voluntary movements, and may play a central role in the pathophysiology of impaired muscle endurance after SD. Supplementary motor area can be noninvasively assessed by electromyogram measuring amplitude of premotor potentials before hand movements. We investigated the effect of SD on muscle endurance in healthy volunteers performing moderate hand exercise by monitoring supplementary motor area activation and muscle afferents. Two sessions were performed, in random order, one after a normal sleep night and the other after a sleepless night. Twenty healthy young men were included in this study. Sleep deprivation reduced time to task failure by 11%. Supplementary motor area activation was altered throughout the task and effort perception was increased. Our results suggest that SD reduces skeletal muscle endurance by increasing the effects of muscle afferents on the supplementary motor area. Sleep alterations frequently reported in chronic diseases might reduce patients' capacity to achieve the low-intensity motor exercises required in everyday life. Our results should lead to the search for sleep disorders in patients with chronic pathology.

Characterization of coping with Primary Dysmenorrhea in Women according to their level of Physical Activity: a cross-sectional observational study.

Primary dysmenorrhoea (PD) is one of the most common gynaecological pathologies in women. The aim is to determine the existence of differences in coping with PD in women who practice high-intensity sport, compared to women who are less physically active. This was a cross-sectional observational study Participants/Materials, Setting, Methods: A total of 476 women were recruited and administered a Google Form multiple-choice questionnaire divided into six sections. The following scales were used: Numerical Pain Rating Scale (NPRS), Pain Catastrophizing Scale (PCS), Menstruation-related Quality of Life Questionnaire (MQOL-22), Tampa Scale for Kinesiophobia (TSK) and Borg scale. Results The 389 participants meeting the inclusion criteria were divided into three groups according to their score in Borg test: high-intensity Physical Activity Group (n=178), moderate-intensity Physical Activity Group (n=101) and low-intensity Physical Activity Group (n=110) for those scoring under 4. ANOVA analysis showed statistical significance only for PCS (p= 0.024). Tukey group per group comparison determined differences between High-intensity Physical Activity Group and Low-intensity Physical Activity Group regarding to PCS (p=0.018). Spearman correlation analysis showed a high relation between PCS and NPRS (r= 0.664) and between MQOL-22 and NPRS (r= -0.562). Limitations The study does not offer a common exercise protocol for all participants, thus physical activity levels in each participant varies in terms of time, intensity, and frequency, which could be crucial when analyzing the results Conclusions According our data, the intensity of the exercise training does not influence in PD-related pain perception nor kinesiophobia. High intensity exercise reduces catastrophizing when compared with sedentary or low intensity exercise. Level of catastrophizing is highly related with perceived pain and quality of life in menstruation in these PD patients. Based on the above, high intensity Physical Exercise could be recommended to reduce the level of catastrophizing in women with Primary Dysmenorrhea.

Adaptation, Validation, and Feasibility Evaluation of Mindful Standing Yoga Combined with Baduanjin for Older Patients with Primary Osteoporosis.

This study aimed to adapt, validate, and evaluate the feasibility of a mindful exercise program (Mindful Standing Yoga combined with Baduanjin) for older patients with primary osteoporosis. The study was conducted in 3 stages. Stage 1 involved a qualitative focus group discussion with 6 experts to gather perspectives on modifying the exercise program. Stage 2 used a Delphi approach with another 6 experts to validate the program. In Stage 3, a feasibility study was conducted with 20 eligible patients (out of 23 initially enrolled) at a traditional Chinese medicine hospital, using a single-group pre- and posttest design. The strenuousness of the adapted exercise was assessed through heart rate (HR) and rating of perceived exertion (RPE). Its effects were measured using the Global Pain Scale (GPS), the Five Facets Mindfulness Questionnaire-Short Form (FFMQ-SF), the Tampa Kinesiophobia-11 Scale, and the Timed Up and Go test. Patient satisfaction and feedback were also collected. The modified program, consisting of 9 movements and taking 30 min to complete, was validated by experts as suitable, safe, and effective for practice. HR and RPE measurements confirmed it as a low-intensity exercise and not strenuous for the study population. The program significantly improved back pain and mindfulness in the feasibility study, with most participants expressing satisfaction with the protocol. Experts and participants affirmed that the program was appropriate and satisfactory for older patients with primary osteoporosis, particularly those with back pain. Further high-quality randomized controlled trials are needed to validate its effectiveness.

Abstract 4137181: High-Intensity Walking Exercise Minutes and Improved Walking Performance in Peripheral Artery Disease: LITE Randomized Clinical Trial

Background: The LITE randomized clinical trial evaluated the effect of high-intensity vs low-intensity walking exercise on walking ability for peripheral artery disease (PAD). In post-hoc analyses, this study evaluated whether people with PAD who walked more exercise minutes per week had greater six-minute walk (6MW) improvement, compared to those who walked fewer exercise minutes per week. Within each quartile of exercise minutes, change in 6MW was compared between high and low-intensity exercise groups. Methods: People with PAD were randomized to walking exercise that induced ischemic leg symptoms (high-intensity), walking exercise at a comfortable pace without ischemic leg symptoms (low-intensity), or a control group that did not exercise for 12 months. Participants randomized to exercise were asked to walk 5 days/week up to 50 minutes/day. High-intensity exercise was defined and objectively measured using an ActiGraph. Participants wore an ActiGraph during exercise to measure exercise minutes/week. The primary outcome was 12-month change in 6MW. Results: Of 305 PAD participants randomized (47% women, 59% Black), 208 were assigned to exercise and had data available for analyses. The high-intensity exercise group walked fewer exercise minutes/week than the low-intensity exercise group (51.95 vs 136.82, P&lt; 0.0001). In each exercise group, greater exercise minutes/week at target intensity were associated with greater 6MW improvement (Table). Within each quartile of exercise minutes/week, high-intensity exercise improved 6MW significantly more than low-intensity (Table). Conclusion: In the LITE randomized trial, among people randomized to high-intensity and low-intensity exercise, respectively, more minutes of exercise per week were associated with greater 6MW improvement. However, within each quartile of exercise minutes/week, high-intensity exercise improved 6MW significantly more than low-intensity exercise.

Neuromuscular Regeneration of Volumetric Muscle Loss Injury in Response to Agrin-Functionalized Tissue Engineered Muscle Grafts and Rehabilitative Exercise.

Neuromuscular deficits compound the loss of contractile tissue in volumetric muscle loss (VML). Two avenues for promoting recovery are neuromuscular junction (NMJ)-promoting substrates (e.g., agrin) and endurance exercise. Although mechanical stimulation enhances agrin-induced NMJ formation, the two modalities have yet to be evaluated combinatorially. It is hypothesized that the implantation of human myogenic progenitor-seeded tissue-engineered muscle grafts (hTEMGs) in combination with agrin treatment and/or exercise will enhance neuromuscular recovery after VML. The hTEMGs alone transplant into VML defects promote significant regeneration with minimal scarring. A sex-appropriate, low-intensity continuous running exercise paradigm increases acetylcholine receptor (AChR) cluster density in male mice twofold relative to hTEMG alone after 7weeks of treadmill training (p<0.05). To further promote neuromuscular recovery, agrin is incorporated into the scaffolds via covalent tethering. In vitro, agrin increases the proliferation of hMPs, and trends toward greater myogenic maturity and AChR clustering. Upon transplantation, both hTEMGs+agrin and hTEMGs+exercise induce near 100% recovery of muscle mass and increase twitch and tetanic force output (p>0.05). However, agrin treatment in combination with exercise produces no additional benefit. These data highlight the unprecedented regenerative potential of using hTEMGs together with either agrin or exercise supplementation to treat VML injuries.

Prenatal exercise and its effects on postpartum mental health: systematic review and meta-analysis.

The perinatal period, spanning from pregnancy through the first year after childbirth, is characterized by significant physiological, psychological, and socio-contextual changes. Women face complex stressors including psychosocial pressures, financial constraints, interpersonal dynamics, anticipatory stress related to parenthood, hormonal fluctuations, and societal expectations. These factors collectively influence the perinatal experience, increasing vulnerabilities and stress levels. A systematic review was conducted in October 2023 using PubMed, SPORTDiscus, PsycInfo, and Scopus databases. Only English-language publications were included. For the meta-analysis, only randomized controlled trials (RCTs) using the Edinburgh Postnatal Depression Scale (EPDS) were considered. Data extraction was performed independently by two reviewers using Covidence, focusing on study characteristics, population demographics, interventions, and outcomes. The initial search identified 2,373 articles, with 1,196 duplicates removed, leaving 1,177 articles. After screening titles and abstracts, 1,247 were excluded for not meeting the inclusion criteria, resulting in 30 full-text articles reviewed for eligibility by two researchers. Nineteen studies were included in the systematic review, with four in the meta-analysis. Results indicated that higher levels of physical activity during pregnancy were consistently associated with improved postpartum mental health outcomes, including reduced depressive symptoms, lower anxiety, and enhanced overall well-being. Low-intensity exercises, such as yoga, were particularly effective in reducing postpartum depressive symptoms. The impact of moderate-intensity exercise varied, with some studies showing no significant effects. The meta-analysis of four RCTs using the EPDS demonstrated a significant reduction in depression and anxiety symptoms among postpartum women who participated in physical activity interventions, with a substantial overall effect size. Developing physical activity and exercise regimens encompassing a range of intensities can address the unique physiological and psychological demands of the perinatal period, maximizing the therapeutic benefits of physical activity interventions.

High- versus low-intensity resistance exercise in the treatment of pain in patients with knee osteoarthritis

High- versus low-intensity resistance exercise in the treatment of pain in patients with knee osteoarthritis

Differences in landing biomechanics in the presence of delayed onset muscle soreness following or not active recovery

ObjectiveDelayed onset muscle soreness (DOMS) can reduce joint range of motion and strength, cause edema, and increase joint stiffness. Here we set out to determine whether quadriceps DOMS followed by an active recovery low-intensity exercise alters jump landing biomechanics. Methods3D landing kinematics, kinetics, and DOMS were evaluated in 26 healthy adults (15 women) performing drop and vertical jump landings before and after a squat protocol to induce quadriceps DOMS. In the presence of DOMS, half of the participants (n = 13) performed a low-intensity exercise for active recovery (10-minute treadmill walking), while the other half (n = 13) did not. Descriptive statistics and generalized estimative equations were applied to determine the effects of DOMS and active recovery on landing kinematics and kinetics. ResultsDOMS decreased knee and ankle flexion angles and increased knee and ankle frontal plane angles during vertical jumps. DOMS elicited a longer time to reach peak ground reaction force during drop jumps. Low-intensity exercise for active recovery reduced DOMS perception but did not alter the biomechanics of landing. ConclusionDOMS changes landing strategy. However, including a low-intensity exercise for active recovery before landing practice did not change the kinematics and kinetics of landing.

Home-Based, Low-Intensity, Gamification-Based, Interactive Physical-Cognitive Training for Older Adults Using the ADDIE Model: Design, Development, and Evaluation of User Experience.

Declines in physical and cognitive function are natural biological processes, leading to an increased risk of falls. Promising evidence suggests that combined physical-cognitive exercise has beneficial effects in improving both physical and cognitive health. Although moderate-to-high exercise intensity is commonly recommended, it might be impractical for older adults facing physical limitations or contraindications. Thus, low-intensity exercise is a viable option. The main barriers to engaging in exercise in older adults include transportation, time, motivation, and enjoyment. To overcome these challenges, a home-based, gamification-based training system may provide an effective approach to enhance exercise adherence. This study aimed to develop and evaluate the usability of a low-intensity, gamification-based, interactive physical-cognitive exercise for older adults in a home-based setting. The prototype of a game-based physical-cognitive exercise was created following the ADDIE model (analysis, design, development, implementation, and evaluation) and assessed for user experience in older adults. A total of 15 older adults engaged in the game-based physical-cognitive exercise at home for 60 minutes per day, 3 days per week, for 4 weeks. The usability of the game-based training system was evaluated using the system usability scale (SUS) after completion of a 4-week training program. As for satisfaction, the 8-item Physical Activity Enjoyment Scale (PACES) questionnaire was used to assess participants' enjoyment level after 1 week and 4 weeks of training. Descriptive statistics were used to illustrate the SUS score. A Wilcoxon signed-rank test was used to compare the PACES scores between the first week and the end of the 4-week period, with significance set at P<.05. As for experts' consensus, the game-based training consisted of 3 games: Ocean Diver, Road Runner, and Moving and Memorizing. The games had 3 levels of difficulty: beginner, intermediate, and advanced. A computer vision-based system was selected as the delivery platform for a home setting. The total SUS score for all participants was mean 87.22 (SD 5.76), indicating the user's perception of the usability of a system ranging from good to excellent. At the end of the 4-week training, the total PACES score was significantly greater than the first week, suggesting an improvement in enjoyment (first week: mean 44.93, SD 3.99 vs fourth week: mean 50.53, SD 4.70; P=.001). The prototype of low-intensity, gamification-based, interactive physical-cognitive training was designed and developed using the ADDIE model, which included both experts and end users in the process. The findings showed that the exergame prototype was a usable and practical approach for a home-based setting, enhancing older adults' enjoyment and motivation. Further research is warranted to determine the effectiveness of such gamification-based training in promoting physical and cognitive functions.

Post-exercise hypotension after different volumes of combined calisthenic and walking exercises in older adults with hypertension: a randomized controlled trial.

This study aimed to analyze the acute effects of combined calisthenic and walking exercises using different volumes on blood pressure (BP) in aging adults with primary hypertension. A total of 48 participants with primary hypertension aged 50-80 years were randomly assigned into two groups that performed two experimental sessions each: a non-exercising CONTROL session and a LOW (group 1) or HIGH (group 2) volume exercise session. The order of these sessions was randomized. The exercise protocols lasted 30 min (LOW) or 60 min (HIGH) and consisted of calisthenic exercises combined with continuous walking or jogging. Exercise intensity was controlled using a rating of perceived exertion (RPE) scale. BP was measured at baseline and after each session for 60 min. Results showed that systolic BP was lower after the HIGH session at post 30' (p = 0.03), post 40' (p = 0.03), post 50' (p = 0.04), and post 60' (p < 0.02), and after the LOW session at post 30' (p = 0.02), post 40' (p < 0.01), post 50' (p < 0.01), and post 60' (p < 0.01) when compared to the corresponding CONTROL at the same time point. There were no significant differences in systolic and diastolic BP between the HIGH and LOW sessions. In conclusion, a pragmatic combined training session using different volumes acutely reduces BP in older adults with primary hypertension.

THE EFFECT OF EXERCISES OF DIFFERENT INTENSITY APPLIED AFTER TOTAL KNEE ARTHROPLASTY ON POST-OPERATIVE PAIN: RANDOMIZED CONTROLLED TRIAL

Purpose: This study aimed to investigate the changes in pain following exercise sessions with different intensities in patients who underwent total knee arthroplasty (TKA). Methods: This is a repeated measure and single-blinded randomized controlled study. Thirty-six patients who underwent TKA (age, 64.9 ± 7.42 years) were randomly assigned to either low-intensity exercises (LIEs) group or high-intensity exercises (HIEs) group. Exercise programs lasted for five days during the hospitalization period. Pain intensity was assessed by visual analog scale (VAS) and pressure pain thresholds (PPTs) were measured over quadriceps and biceps brachii and muscles immediately before and after exercise. Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) subscale (pain, stiffness, and physical function) scores were recorded at two points in baseline and discharge from the hospital. Results: The pain intensity decreased in patients in both groups after TKA. PPTs increased in both groups at all tested sites following the first, third, and fifth exercise bouts. HIE program had a greater positive effect on the pain intensity after the first exercise session than LIE program on the PPTs ([Formula: see text] &lt; 0.05). HIE program was more effective in order to reduce pain severity immediately after the exercise sessions in patients ([Formula: see text]: 0.5, [Formula: see text] &lt; 0.05). WOMAC scores significantly improved in both groups during the discharge from the hospital ([Formula: see text] = 0.001). Conclusion: Our results found that both LIE and HIE programs performed during hospitalization after TKA declined pain intensity. Particularly notable were the substantial improvements observed in managing post-operative pain, especially following the second exercise session. The HIE program proved more effective in improving stiffness, and enhancing physical function.

The effect of table tennis combined with resistance training on the rehabilitation of patients with coronary heart disease

Abstract: PURPOSE: The purpose of the study was to explore the influence of table tennis combined with resistance training on coronary heart disease (CHD) rehabilitation and to evaluate its potential in improving cardiopulmonary function, arterial stiffness, blood lipids, and psychological indicators in participants with CHD. METHODS: Seventy patients with confirmed CHD were chosen and randomly separated into two groups, 35 cases each. The test group performed table tennis combined with resistance training, and the reference group (RG) received standard resistance training as the control group. By comparing the differences in cardiopulmonary function, arterial stiffness, sleep and diet, psychological indicators, and blood lipids between the two groups of patients, the role of table tennis combined with resistance training in CHD rehabilitation was evaluated. RESULTS: Relative to the control group, participants in the table tennis exercise combined with the resistance training group had significant improvement in cardiopulmonary function (P &lt; 0.05). In addition, table tennis combined with resistance training can reduce patients’ arterial stiffness, improve sleep and eating habits, and reduce blood lipid levels. Relative to the RG, the data possess the statistical significance (P &lt; 0.05). Finally, the psychological quality of the two groups of patients was compared. The anxiety, depression, and confrontation ability of the patients in the test group were 7.15 ± 0.39, 7.03 ± 0.29, and 6.86 ± 0.46, respectively, which were superior to the RG. The comparison among the participants of data possesses the statistical significance (P &lt; 0.005). CONCLUSION: The research results show that table tennis combined with resistance training possesses an essential influence on CHD rehabilitation. It can significantly enhance patients’ cardiopulmonary function, reduce arterial stiffness, improve sleeping and eating habits, reduce blood lipid levels, and improve psychological indicators. As a low-intensity aerobic exercise, table tennis possesses an essential influence on facilitating the recovery of patients with CHD and is worthy of further promotion and application in clinical practice.

Effect of Aerobic Exercise with Blood Flow Restriction on Postexercise Hypotension in Young Adults: The Role of Histamine Receptors.

We tested hypothesis that aerobic exercise with blood flow restriction (BFR) induced postexercise hypotension (PEH), and the reduction in blood pressure (BP) was due to peripheral vasodilation via the histamine receptors. Ten male subjects participated in this study. The subjects were randomly assigned to walk for 10 min at 6.4 km/h, 0% grade with or without BFR after taking histamine receptor blockade. Following exercise, BP was measured at 10 min interval for 60 min. Heart rate (HR), stroke volume (SV), cardiac output (CO), mean arterial pressure (MAP), and total peripheral resistance (TPR) were evaluated. Our results indicated that MAP was significantly lowered immediately after exercise at 20 min, 30 min, and 40 min before the blockade as opposed to after the blockade. A significant reduction in diastolic BP (DBP) occurred. There were no significant differences in HR, SV, CO, and TPR between before the blockade and after the blockade. MAP was substantially decreased at 20 min, 30 min, and 40 min before the blockade compared to resting (-3.2 ± 2.2, -3.3 ± 2.8, and -2.9 ± 2.5, respectively) while increasing MAP after the blockade. The current study demonstrated that low-intensity aerobic exercise with BFR lowered MAP via histamine receptor-induced peripheral vasodilation. In conclusion, BFR exercise training using short periods and low intensity would be greatly beneficial as a potential treatment to lower BP.

Evaluating a novel portable semiconductor liquid cooling garment for reducing heat stress of healthcare workers in a hot-humid environment

Limited research focused on exploring personal cooling garments (PCGs) that offer excellent portability, along with a substantial, long-lasting, and consistent cooling effect for healthcare workers exposed to extreme heat while combating the COVID-19 pandemic. To address this gap, a novel, energy-efficient, and portable semiconductor liquid cooling garment (SLCG) was introduced, which incorporates a semiconductor-powered cold source and a cooling vest crafted from a semi-transparent thermoplastic polyurethane (TPU) film that offers extensive body coverage. Its practical cooling efficacy was assessed through a human trial involving ten male participants engaging in two protocols under a hot-humid environment (i.e., 30 ± 0.5 °C, RH = 80 ± 5 %). These protocols included both low-intensity (Prot.1) and moderate-intensity (Prot.2) exercises, mimicking the physical demands faced by healthcare workers. SLCG significantly reduced the mean, torso and local skin temperatures during both Prot.1 and Prot.2 (p < 0.05), also with a notable reduction in heart rate and sweat loss during Prot.1 (p < 0.05). Rating of perceived exertion as well as thermal sensations, wetness sensations and comfort sensations in the whole-body and local-body (i.e., head & neck, trunk, arms and legs) were all remarkably improved using SLCG during Prot.1 (p < 0.05). These perceptual sensations in SLCG were only improved in the whole body during the resting stage, and in the trunk region during Prot.2 (p < 0.05). Furthermore, participants felt no significant added weight or movement restrictions with SLCG in either protocol.

Acute Effect of Three Aerobic Exercise Intensities on Glomerular Filtration Rate in Healthy Older Adults.

To assess the immediate effects of three aerobic exercise intensities on the estimated glomerular filtration rate (eGFR) in healthy, sedentary older adults. Eighteen healthy, sedentary older adults (ten men and eight women) voluntarily participated in this study. The participants underwent three standardized aerobic exercise tests (100%, 80%, and 60% of the maximal heart rate) on a bicycle ergometer. Blood samples were collected to determine cholesterol, triacylglycerols, glucose, serum creatinine (Cr), Cystatin C (CysC) concentrations, and eGFR. eGFR and serum concentrations of Cr and CysC were not modified at any exercise intensity. There was a negative correlation between blood total cholesterol vs. eGFR (R = -0.512, R = -0.582, R = -0.531; p < 0.05) at rest, 60%, and 100% of the maximal heart rate, respectively. In addition, a negative correlation existed for age vs. eGFR at 60% of the maximal heart rate (R = -0.516; p < 0.05). Short-duration aerobic exercise of low, moderate, and vigorous intensity did not significantly affect eGFR and is considered safe for kidney function in healthy, sedentary older adults. However, regular monitoring of kidney function in older people engaged in moderate- and high-intensity exercise is advised.

Effectiveness of community-based Baduanjin exercise intervention for older adults with varying frailty status: a randomized controlled trial

BackgroundDue to poorer exercise tolerance, it may be challenging for frail older adults to engage in moderate- or vigorous-intensity exercise. While low-intensity exercise interventions may be more feasible, its effectiveness for such population group remains unclear. We examined the effectiveness and implementation of community-based Baduanjin Qigong, a low-intensity exercise program in older adults with varying frailty status.MethodsA two-arm, multicenter assessor-blind parallel group randomized controlled trial was conducted at three local senior activity centers. Fifty-six community-dwelling older adults with low handgrip strength were randomly allocated to either the intervention (IG) or wait-list control (CG) group. The IG underwent a supervised 16-week Baduanjin exercise program at a frequency of 2–3 × 60 min sessions/week. The CG was instructed to maintain their usual activity and received a monthly health education talk. The primary outcome measures were knee extension strength, vital exhaustion, and fear of falling. Secondary outcome measures include physiological falls risk, handgrip strength, gait speed, timed up and go test, 30-second sit-to-stand, quality of life, depression, and frailty. All outcome measures were assessed at baseline and 4-month follow-up.ResultsOverall, there were no statistically significant differences in all outcome measures between CG and IG at 4-month follow-up. However, in exploratory compliance analysis, a statistically significant group x time interaction was found for vital exhaustion (B = -3.65, 95% CI [-7.13, -0.16], p = .047) among participants with at least 75% attendance. In post-hoc within-group comparisons, IG showed improved vital exhaustion by 4.31 points (95% CI [1.41, 7.20], d = 0.60). The average participant attendance rate was 81.3%. No major adverse events occurred, and all participants reported positive experiences with the exercise intervention.ConclusionsOur study demonstrated that Baduanjin is a safe, feasible, and acceptable exercise program that can be successfully implemented in community settings for older adults with varying frailty status. With good adherence, Baduanjin exercise could potentially be effective in alleviating vital exhaustion. However, the effectiveness of Baduanjin on physical performance, psychological measures and frailty in community-dwelling older adults remains equivocal.Trial registrationClinicalTrials.gov NCT04549103. Registered September 16, 2020.