Exercise Intensity Research Articles

Acute effects of exercise on gaze fixation and affective response inhibition in children with autism spectrum disorder: A randomized cross-over study.

Children with autism spectrum disorder (ASD) show impairments in response inhibition, especially in socio-emotional contexts. A single aerobic exercise session has the potential to temporarily reduce such impairments as findings from neurotypical children support acute benefits of this exercise type for inhibitory control and emotion recognition. In children with ASD, we therefore aimed to investigate the effects of an aerobic exercise bout on response inhibition in an emotional Go/NoGo task and gaze fixation as possible mechanism underlying changes in performance. Using a cross-over design, 29 patients completed a 20-min aerobic exercise bout at moderate intensity on a cycling ergometer and a control condition in a randomized order. An emotional Go/NoGo task was administered before and after both experimental conditions. Eye-tracking was performed during the cognitive task to assess the duration of gaze fixation of eyes and mouth parts of faces expressing happy or sad emotions. The results support no beneficial effect of exercise on performance on the emotional Go/NoGo task. Instead, patients showed a greater decrease in accuracy on Go trials displaying happy faces in the exercise compared to the control condition. This change was associated with a more pronounced decrease in the fixation duration of the eyes for faces expressing either happy or sad emotions. In conclusion, while a single session of moderately intense aerobic exercise does not affect response inhibition, it temporarily aggravates ASD-specific deficits in the processing of and response to facial emotions.

Changing the Mandibular Position in Rowing: A Brief Report of a World-Class Rower.

We investigated the acute biophysical responses of changing the mandibular position during a rowing incremental protocol. A World-class 37-year-old male rower performed two 7 × 3 min ergometer rowing trials, once with no intraoral splint (control) and the other with a mandibular forward repositioning splint (splint condition). Ventilatory, kinematics and body electromyography were evaluated and compared between trials (paired samples t-test, p ≤ 0.05). Under the splint condition, oxygen uptake was lower, particularly at higher exercise intensities (67.3 ± 2.3 vs. 70.9 ± 1.5 mL·kg-1·min-1), and ventilation increased during specific rowing protocol steps (1st-4th and 6th). Wearing the splint condition led to changes in rowing technique, including a slower rowing frequency ([18-30] vs. [19-32] cycles·min-1) and a longer propulsive movement ([1.58-1.52] vs. [1.56-1.50] m) than the control condition. The splint condition also had a faster propulsive phase and a prolonged recovery period than the control condition. The splint reduced peak and mean upper body muscle activation, contrasting with an increase in lower body muscle activity, and generated an energetic benefit by reducing exercise cost and increasing rowing economy compared to the control condition. Changing the mandibular position benefited a World-class rower, supporting the potential of wearing an intraoral splint in high-level sports, particularly in rowing.

Effects of muscle strength training combined with aerobic training versus aerobic training alone on cardiovascular disease risk indicators in patients with coronary artery disease: a systematic review and meta-analysis of randomised clinical trials

ObjectiveTo compare the effects of aerobic training combined with muscle strength training (hereafter referred to as combined training) to aerobic training alone on cardiovascular disease risk indicators in patients with...

The Influence of Intestinal Microbiota on BDNF Levels.

The regulation of neurogenesis, the complex process of producing and differentiating new brain tissue cells, is influenced by a complex interaction of internal and external factors. Over the past decade, extensive research has been conducted on neurotrophins and their key role in adult neurogenesis, as well as their impact on diseases such as depression. Among neurotrophins, the brain-derived neurotrophic factor (BDNF) has been the subject of comprehensive studies on adult neurogenesis, and scientific evidence supports its necessity for neurogenesis in the subventricular zone of the hippocampus. A novel area of research is the emerging role of gut microbiota as a significant contributor to neurogenesis and neurotrophin production. Studies have shown that reduced BDNF levels can lead to mood disorders, which are observed in intestinal dysbiosis, characterized by an imbalance in the composition and quantity of the intestinal microbiota. There is evidence in the literature that there is a link between brain function and gut microbiota. Physical activity, and especially the regularity and intensity of exercise, is important in relation to the level of BDNF and the intestinal microbiota. Probiotics, prebiotics and physical activity may have a positive effect on the intestinal microbiota, and therefore also on the level of the brain-derived neurotrophic factor.

Physical exercise as a cognitive rehabilitation treatment after traumatic brain injury: Intensity- and sex-dependent effects

We investigated the effects of forced physical exercise (PE) intensity on cognitive dysfunction and histological changes associated with traumatic brain injury (TBI), in both male and female rats. Controlled cortical impact (CCI) produced similar short- and long-term memory deficits in both sexes, and these deficits were associated with reduced volume and neuronal loss in the hippocampus, but not with changes in neurogenesis. We found sex differences in the effects of intensity of forced PE on cognitive recovery: all PE intensities tested improved short-term memory in both sexes, but to a greater extent in females, while long-term memory benefits were intensity- and sex-dependent. Males benefited most from low-intensity PE, while females showed optimal results at moderate intensity. These optimal PE intensities increased the neurogenesis in both sexes. A neuroprotective effect of low-intensity PE was evident in males, but no effect was observed in females. These findings suggest an intensity- and sex-specific effect of PE post-TBI, emphasizing the need for tailored PE protocols based on sex to enhance therapeutic outcomes.

Psychological Study on the Influence of Physical Exercise on College Students’ Anxiety

This study aims to explore the impact of physical exercise on the anxiety level of college students. We collected physical exercise data and anxiety self-assessment results from college students of different grades, genders, and ages from multiple universities in Guangdong Province through a questionnaire survey. The study used standardized scales to evaluate participants’ physical exercise types, frequencies, intensities, and anxiety levels. The data analysis results showed that there is a significant negative correlation between college students’ physical exercise and anxiety level, that is, the more frequent and intense the physical exercise, the lower the anxiety level. In addition, there are differences in the effect of different types of physical exercises on anxiety relief, with aerobic exercises such as running and swimming showing more significant anxiety-relieving effects. The research results provide valuable references for psychological health education and anxiety intervention strategies in universities and suggest promoting physical exercise to effectively alleviate college students’ anxiety.

Intervention effect of exercise on working memory in patients with depression: a systematic review.

This article aims to systematically evaluate the intervention effect of exercise on working memory in patients with depression. Six Chinese and English databases were searched for randomized controlled trials (RCTs) about exercise on working memory in patients with depression. PEDro scale was adopted to evaluate the methodological quality of the included articles, GRADEpro scale was employed to evaluate the level of evidence for outcomes, and the Metafor Package in R 4.4.1 was used to analyze the combined effect size, subgroup analyses and publication bias. A total of 15 studies were included. The meta-analysis indicated that exercise had a statistically significant effect on working memory in patients with depression, with an effect size of 0.16 (95% CI [0.03-0.28], p = 0.02). Exercise type (F(3,34) = 1.99, p = 0.13), intervention content (F(1,36) = 1.60, p = 0.22), and exercise duration (F(1,36) = 0.05, p = 0.83) did not moderate the effect, whereas exercise intensity showed a moderating effect (F(2,35) = 8.83, p < 0.01). There was evidence of publication bias in the study results (t = 2.52, p = 0.02). Exercise can improve the working memory of patients with depression, and its moderating effect is the best when having low-intensity and moderate-intensity. Research plan was registered in international system evaluation platform PROSPERO (https://www.crd.york.ac.uk/PROSPERO/) (CRD42023475325).

A mendelian randomisation study of the causal effect of exercise intensity on the development of type 2 diabetes.

This study examines the causal effects of varying exercise intensities on type 2 diabetes mellitus (T2D) through Mendelian randomization (MR) analysis, using genetic variants as instrumental variables. A two-sample MR analysis was performed, employing Inverse Variance Weighted (IVW) as the primary method, supported by weighted median, MR-Egger regression, MR-PRESSO, and MR robustness-adjusted contour scores. Data were obtained from the International Exercise Genetics Database (IEGD) and the Global Diabetes Research Consortium (GRC), encompassing over 150,000 individuals for exercise intensity and around 200,000 T2D patients and controls. SNPs linked to exercise intensity were selected based on genome-wide significance (P < 5 × 10^-8) and linkage disequilibrium criteria (distance >10,000kb, r^2 < 0.001). The IVW analysis suggested that high-intensity exercise might reduce T2D risk, but the association was not statistically significant (OR = 0.667, 95% CI = 0.104-4.255, P = 0.667). The wide confidence interval indicates uncertainty in the effect estimate. Low-intensity exercise showed no significant effect on T2D risk (OR ∼ 1.0). Sensitivity analyses, including weighted median and MR-Egger regression, confirmed no significant association between high-intensity exercise and T2D risk. The MR-PRESSO analysis found no significant outliers, and the global test for pleiotropy was non-significant (P = 0.455). Cochran's Q test for heterogeneity in the IVW analysis was non-significant (Q = 12.45, P = 0.234), indicating consistency among SNP-derived estimates. High-intensity exercise potentially reduces T2D risk, but the association is not statistically significant. Further research is needed to understand the complex relationship between exercise intensity and T2D.

Exercise intensity prescription in cardiovascular rehabilitation: bridging the gap between best evidence and clinical practice.

Optimizing endurance exercise intensity prescription is crucial to maximize the clinical benefits and minimize complications for individuals at risk for or with cardiovascular disease (CVD). However, standardization remains incomplete due to variations in clinical guidelines. This review provides a practical and updated guide for health professionals on how to prescribe endurance exercise intensity for cardiovascular rehabilitation (CR) populations, addressing international guidelines, practical applicability across diverse clinical settings and resource availabilities. In the context of CR, cardiopulmonary exercise test (CPET) is considered the gold standard assessment, and prescription based on ventilatory thresholds (VTs) is the preferable methodology. In settings where this approach isn't accessible, which is frequently the case in low-resource environments, approximating VTs involves combining objective assessments-ideally, exercise tests without gas exchange analyses, but at least alternative functional tests like the 6-minute walk test-with subjective methods for adjusting prescriptions, such as Borg's ratings of perceived exertion and the Talk Test. Therefore, enhancing exercise intensity prescription and offering personalized physical activity guidance to patients at risk for or with CVD rely on aligning workouts with individual physiological changes. A tailored prescription promotes a consistent and impactful exercise routine for enhancing health outcomes, considering patient preferences and motivations. Consequently, the selection and implementation of the best possible approach should consider available resources, with an ongoing emphasis on strategies to improve the delivery quality of exercise training in the context of FITT-VP prescription model (frequency, intensity, time, type, volume, and progression).

The impact of exercise on mental health: a narrative review

It has become increasingly clear that exercise not only improves physical health but also significantly affects mental well-being, presenting a non-pharmaceutical approach to manage various psychological conditions. This narrative review summarizes studies from the literature to understand the effects of exercise on mental health, particularly in depression, anxiety, and global psychological well-being. Results indicate that regular physical activity, including aerobic and resistance exercises, reduces depression and anxiety symptoms, improves mood, and enhances cognitive abilities. Theoretical models, such as the endorphin hypothesis and neurogenesis hypothesis, explain these benefits through mechanisms including endorphin release, reduced stress hormones, improved sleep, and neurogenesis. Evidence suggests that structured exercise programs can match the effectiveness of psychotherapy or medication with fewer adverse effects. The benefits of regular exercise have garnered attention from professionals, physicians, and policymakers, highlighting the necessity of incorporating exercise plans into mental health clinical practice. Additionally, this review advocates for more specific and personalized exercise interventions tailored to individual characteristics and preferences. It also aims to inform health and research agendas by specifying the optimal exercise type and intensity for eliciting desired benefits, and evaluating the potential for exercise interventions to sustain long-term psychological well-being.

Social facilitation of trotting: Can horses perceive and adapt to the movement of another horse?

Exercise intensity is prone to be self-regulated in horses exercising freely. The main drivers include social, feeding and escape behaviors, as well as the operant conditioning. We hypothesized that self-regulated exercise intensity may increase due to the presence of another horse exercising ahead. Seven horses were assigned to a 2x2 crossover trial following treadmill familiarization. Video images of a trotting horse were displayed on the wall in front of the experimental unit (Visual), which was positioned in the treadmill. Physiological and behavioral markers were further compared with a control visual stimulus (Co), comprising a racetrack image without horses. Horses were sampled during a constant load exercise test (1) at rest (baseline), (2) after the warm-up (0 - 10th minute) and (3) after visual stimulation or control (10th- 12th minutes of the SET) to quantify plasma lactate and glucose concentration, heart rate, head angle, as well as behavioral markers. Following visual stimulation, heart rate (130.8 ± 27.8 b.p.m.) was higher than control (84.7 ± 15.1 b.p.m., P = .017), as was plasma lactate (Visual - 5.28 ± 1.48 mg/dl; Co -3.27 ± 1.24 mg/dl, P = .042) and head angle (Visual - 36.43 ± 3.69°; Co -25.14 ± 4.88°, P = .003). The prevalence of "ears forward" behavior was also higher following Visual (100% - 7/7) than Co (14% - 1/7, P = .004). These results suggest that visual stimulus (1) was safe and well tolerated and (2) prompted the anaerobic lactic pathways and shifted the behavior to a vigilant state. In conclusion, horses were able to perceive and adapt to a social environment. Our findings validate the use of social facilitation of trotting to encourage horses to move forward avoiding the use of the whip.

Reliability and validity of the ratings of perceived stability scale as a measure of balance exercise intensity in persons with multiple sclerosis

Purpose The study aimed to determine the test-retest reliability and concurrent validity of the Ratings of Perceived Stability (RPS) scale as a measure of balance exercise intensity in persons with multiple sclerosis (MS). Methods Twenty participants with MS (mean age: 58.1 ± 15.29; 60% female) performed 14 balance tasks on two separate occasions wearing body-worn inertial sensors and rated their perceived stability for each task. Sensor data included sway velocity and angle, gait speed, turn velocity, and lean angle. Intraclass correlation coefficients (ICC) and Spearman rank correlations (r s) were employed to assess reliability and validity, respectively. Results The RPS showed good to excellent test-retest reliability (ICC> 0.75) on 12 out of the 14 tasks. The stability ratings revealed moderate relationships with postural sway outcomes in static balance tasks (r s: 0.49 to 0.77) and weak to moderate associations with gait speed (r s: −0.69 to −0.14). Ratings of stability were also strongly related to turn velocity (r s= −0.77) and moderately related to lean angle (r s= 0.58). Conclusions The RPS scale offers a promising clinical tool to measure balance exercise intensity for persons with MS. This standardized scale allows for tailored balance training with a novel means for exercise monitoring and progression in this population.

A comparison of continuous, interval, and accumulated workouts with equalized exercise volume: excess post-exercise oxygen consumption in women

BackgroundDespite the well-known health benefits of exercise, women’s participation in exercise is low worldwide. As women are at risk of developing various chronic diseases as they age, suggesting effective exercise methods that can maximize energy consumption is needed to prevent such conditions. Excess post-exercise oxygen consumption (EPOC) can maximize energy consumption. In this crossover, randomized controlled trial, we aimed to compare the EPOC for different exercise modalities including continuous exercise (CE), interval exercise (IE), and accumulated exercise (AE) that spent the homogenized energy expenditure during exercise in healthy women.MethodsForty-four participants (age, 36.09 ± 11.73 years) were recruited and randomly allocated to three groups. The intensity of each modality was set as follows: CE was performed for 30 min at 60% peak oxygen uptake (VO2peak). IE was performed once for 2 min at 80% VO2peak, followed by 3 min at 80% VO2peak, and 1 min at 40% VO2peak, for a total of six times over 26 min. AE was performed for 10 min with a 60% VO2peak and was measured thrice a day.ResultsDuring exercise, energy metabolism was higher for IE and CE than that for AE. However, this was reversed for AE during EPOC. Consequently, the greatest energy metabolism was shown for AE during total time (exercise and EPOC).ConclusionsBy encouraging regular exercises, AE can help maintain and improve body composition by increasing compliance with exercise participation, given its short exercise times, and by efficiently increasing energy consumption through the accumulation of EPOC.Trial registrationClinical number (KCT0007298), 18/05/2022, Institutional Review Board of Konkuk University (7001355-202201-E-160).

Recent Findings on Exercise Therapy for Blood Glucose Management in Patients with Gestational Diabetes.

Inadequate management of blood glucose levels in gestational diabetes mellitus (GDM) poses risks for both pregnant women and the developing fetus. Attaining appropriate blood glucose control is crucial to mitigate potential adverse outcomes. This study aimed to consolidate the latest guidelines from representative professional societies, providing insights into exercise therapy for GDM patients and suggesting potential avenues for future research. The review was conducted with up-to-date exercise guidelines from prominent societies, such as the American College of Obstetricians and Gynecologists (ACOG), the Society of Obstetricians and Gynecologists of Canada (SOGC), the Canadian Society for Exercise Physiology (CSEP), the American College of Sports Medicine, the American Diabetes Association (ADA), and the Korean Diabetes Association. The ACOG and SOGC/CSEP recommend 150 min of low to moderate intensity exercise, 3-4 times a week, combining aerobic and resistance exercises. All guidelines advise against activities involving sudden directional changes, physical contact, a risk of falling, and exercises performed lying down. Despite cautions from the ADA and ACOG on blood glucose fluctuations during physical activity, the lack of specific methods and recommendations from other societies reveals a notable gap in evidence-based guidelines for GDM. For effective and safe blood glucose management in GDM patients, further research should be conducted on the exercise-related precautions outlined for GDM patients. Establishing ample evidence would facilitate the development of customized exercise guidelines for GDM patients.

Comparing Physical Activity and Exercise Experiences, Values, and Beliefs of Latino, Latina, and/or Latine People and Non-Latino, Non-Latina, and/or Non-Latine People With Parkinson Disease: A Qualitative Study.

The objective of this study was to examine and compare the beliefs, values, experiences, and barriers to and facilitators of exercise in Latino/a/e (Latino, Latina, and/or Latine) people and non-Latino/a/e (non-Latino, non-Latina, and/or non-Latine) people with Parkinson disease (PD). This study involved a qualitative research design with data collection via focus groups of Latino/a/e and non-Latino/a/e people with PD. A semistructured interview protocol was used, and a theoretical (social ecological model) thematic analysis was used for data analysis. Twenty-five individuals (15 non-Latino/a/e and 10 Latino/a/e) participated across 5 focus groups. While there were several common themes among both groups, 7 themes related to exercise in the management of PD were unique to Latino/a/e participants: generalized versus specific knowledge of exercise components; family can have both facilitating and impeding roles; finances influence access to exercise and physical therapy; prior emotional experiences related to exercise and PD affect the future use of exercise; group exercise can have both facilitating and impeding roles; availability and access to a variety of modes and stratification of exercise classes for people with PD facilitate exercise; and cultural beliefs and expectations can impede the use of exercise at the population level. Latino/a/e people with PD have overlapping and unique themes related to the use of exercise. Distinctive factors must be addressed in physical activity interventions and during physical therapists' care of people with PD to maximize the use of exercise and ultimately improve health equity in this overburdened and underserved population. Physical therapists should provide information and education to their Latino/a/e patients with PD and family members on the frequency, intensity, type, and time of exercise and how to safely participate in physical activity in the home and community to best manage PD. Physical therapists and exercise professionals should work at the environmental level to increase access to affordable, culturally tailored, PD-specific exercise services and enhance community knowledge of PD.

Triad of rehabilitation, nutrition support, and oral management improves activities of daily living and muscle health in hospitalized patients after stroke

The triad approach combining rehabilitation, nutrition support, and oral management has garnered increasing interest for improving outcomes in older adults. However, evidence is limited regarding its effectiveness in post-stroke patients, who are at high risk for malnutrition, sarcopenia, oral problems, and dysphagia. This study aims to investigate the association between the triad approach and improvement in activities of daily living (ADL), muscle strength, and skeletal muscle mass in these patients. A retrospective cohort study was conducted using post-stroke patients. Patients were divided into groups based on their exposure to the triad approach, defined as a combination of intensive chair-stand exercise (rehabilitation), personalized food prescriptions (nutrition support), and oral management by dental professionals. We investigated the association between the triad approach and outcomes using multiple linear regression analysis adjusted for covariates. Primary outcome was Functional Independence Measure motor score (FIM-motor) at discharge and its gain. Secondary outcomes were handgrip strength (HGS) and skeletal muscle mass index (SMI) at discharge. The study included 1,012 post-stroke patients (median age 75.6 years; 54.1% men). Multiple linear regression analysis revealed that the triad approach had the strongest association with higher FIM-motor at discharge (β=0.262, p<0.001) and FIM-motor gain (β=0.272, p<0.001) compared to the individual or combined interventions. The triad also showed the strongest associations with higher HGS (β=0.090, p=0.017) and SMI (β=0.041, p=0.028) at discharge. The triad approach of intensive rehabilitation, personalized nutrition support, and oral management by dental professionals is strongly associated with improved ADL, muscle strength, and skeletal muscle mass in post-stroke rehabilitation patients. Implementing this multidisciplinary strategy may maximize functional and muscle health recovery.

DiADEM-Dance against Dementia-Effect of a Six-Month Dance Intervention on Physical Fitness in Older Adults with Mild Cognitive Impairment: A Randomized, Controlled Trial.

Background: Preserving health and physical fitness is critical to ensure independent living across the lifespan. Lower levels of physical fitness are associated with age-related cognitive decline and a higher prevalence of mild cognitive impairment (MCI). Thus, this study investigates the influence of a six-month dance intervention on selected measures of physical fitness in older adults with MCI. Methods: In this randomized controlled trial, 55 patients with MCI were randomized into a sportive dance training (IG; n = 26; age: 70.7 ± 5.6 years; 62% female) or an inactive control group (CG; n = 24; age: 69.1 ± 6.8 years; 46% female). The dance group received two 90 min dance training sessions per week over a duration of six-months, which focused on learning dance movement patterns. During the training sessions, heart rate was measured to control exercise intensity. Physical fitness was assessed using cardiopulmonary exercise testing (CPET), lower limb functional fitness via sit-to-stand test, handgrip strength, and heart rate variability (HRV). Results: We observed that the dance intervention preserved the cardiorespiratory fitness as measured by maximal oxygen uptake (VO2max) during CPET, which decreased in the CG. Furthermore, participants in the IG demonstrated increases in leg and handgrip strength, although these were not statistically significant. HRV displayed a non-significant decrease following the intervention. Conclusions: The results of this randomized controlled trial suggest that sportive dance training can preserve elements of physical fitness (i.e., cardiorespiratory fitness) in older adults with MCI. Although improvements in the other parameters (i.e., leg and handgrip strength) were statistically non-significant, likely due to the small sample size, stabilizing muscular fitness and preventing age-related decline in older adults with MCI is important for maintaining functional independence. For future studies, we recommend a longer training duration paired with precise control of regular physical activity levels, an important confounding factor.

Plasma, Urinary, Erythrocyte and Platelet Zinc Concentrations in Soccer Players.

Essential trace minerals are vital for general human health and athletic performance. Zinc (Zn) plays critical roles in several biochemical processes in exercise physiology, especially during intense physical exercise. This research aimed to analyze erythrocyte, platelet, plasma and urine Zn concentrations among men's and female soccer players over a sports season. A total of 22 male soccer players (20.61 ± 2.66 years; 71.50 ± 5.93 kg) and 24 female soccer players (23.37 ± 3.95 years; 59.58 ± 7.17 kg) participated in this longitudinal quasi-experimental study. Three assessments were carried out over the season: 1st evaluation: first week of training (August); 2nd assessment: middle of the season, between the end of the first and second round (January) and 3rd assessment: last week of training (May/June). In all evaluations extracellular (plasma and urine) and intracellular (erythrocytes and platelets) Zn concentrations were determined, as well as physical fitness and several blood parameters. Inductively coupled plasma mass spectrometry was used to measure Zn concentrations. Plasma and urinary concentrations were higher among male soccer players (p < 0.05) while erythrocyte and platelet Zn concentrations were higher in the female soccer players (p < 0.05). Additionally, variations in urinary and platelet Zn concentrations were observed over the season. The differences could be related to muscle mass, muscle damage or the specific sport's physical demands.

Combined Impact of Heart Rate Sensor Placements with Respiratory Rate and Minute Ventilation on Oxygen Uptake Prediction.

Oxygen uptake (V˙O2) is an essential metric for evaluating cardiopulmonary health and athletic performance, which can barely be directly measured. Heart rate (HR) is a prominent physiological indicator correlated with V˙O2 and is often used for indirect V˙O2 prediction. This study investigates the impact of HR placement on V˙O2 prediction accuracy by analyzing HR data combined with the respiratory rate (RESP) and minute ventilation (V˙E) from three anatomical locations: the chest; arm; and wrist. Twenty-eight healthy adults participated in incremental and constant workload cycling tests at various intensities. Data on V˙O2, RESP, V˙E, and HR were collected and used to develop a neural network model for V˙O2 prediction. The influence of HR position on prediction accuracy was assessed via Bland-Altman plots, and model performance was evaluated by mean absolute error (MAE), coefficient of determination (R2), and mean absolute percentage error (MAPE). Our findings indicate that HR combined with RESP and V˙E (V˙O2HR+RESP+V˙E) produces the most accurate V˙O2 predictions (MAE: 165 mL/min, R2: 0.87, MAPE: 15.91%). Notably, as exercise intensity increases, the accuracy of V˙O2 prediction decreases, particularly within high-intensity exercise. The substitution of HR with different anatomical sites significantly impacts V˙O2 prediction accuracy, with wrist placement showing a more profound effect compared to arm placement. In conclusion, this study underscores the importance of considering HR placement in V˙O2 prediction models, with RESP and V˙E serving as effective compensatory factors. These findings contribute to refining indirect V˙O2 estimation methods, enhancing their predictive capabilities across different exercise intensities and anatomical placements.

Liver Function Markers Response to Different Exercise Intensities in Athletes A Single Bout Perspective

Exercise provides considerable health advantages through promoting proper body system functioning, healthy growth and development, and quality of life. The present study investigated the effect of single bout High- Intensity Exercise (HIE) compared to Low-Intensity Exercise (LIE) on liver function markers in athletes. This cross-sectional study was carried out in the Department of Physical Education, Banaras Hindu University, Varanasi (UP). A total of 20 healthy male athletes with age range from 22 to 26 years were randomly selected and underwent 5 minutes of HIE and LIE separated by one week. Blood samples for selected liver function markers were taken pre-exercise, immediately, 10 and 20 minutes post-HIE and LIE, respectively. A repeated measures ANOVA with greenhouse-geisser correction found a significant difference between high and low intensity exercises for SGOT (F=5.881; p&lt;0.05) and SBT (F=7.154; p&lt;0.05) values, while statistically insignificant in the case of SGPT (F=1.572; p&gt;0.05). In high intensity exercise there was statistically significant difference for SGOT (F=7.564; p&lt;0.05) value between different time points. Post hoc analysis with a bonferroni correction showed that SGOT value was significantly increased immediately after the HIE, reducing 10 minutes after the exercise and closely returned to baseline level after 20 minutes of exercise, whereas LIE showed no significant changes. Exercise intensity is important as it triggers liver pathology by asymptomatic modifying liver function markers. These findings can be used to develop and administer exercise training plans for athletes.