Physical activity and nutrition最新文献

Purpose: High-intensity exercise increases oxidative stress, disrupts bone remodeling and accelerate bone loss. While vitamin C is commonly used to counteract these effects, high doses may act as pro-oxidants. Cosmos caudatus, a traditional herb rich in antioxidants, may serve as a natural alternative. In this study compared the effects of C. caudatus extract and vitamin C on oxidative stress and bone health in a rat model of exercise-induced oxidative stress.

Methods: Fifty-four male Sprague-Dawley rats (3-4 months old, 200-300 g) were divided into five groups (10-11 rats each). Group P1 received distilled water, whereas groups P2-P4 received C. caudatus extract at 0.91, 1.82, and 3.64 mg/0.5 mL/200 g BW. Group P5 was administered vitamin C at 9 mg/0.5 mL/200 g BW. Treatments were administered orally for 28 days. Rats underwent high-intensity swimming with an 18% BW load at 90% maximal swim time (T90), twice daily, three times weekly. Femoral and blood samples were collected for malondialdehyde (MDA), osteocalcin (OC), C-telopeptide (CTX), trabecular bone ratio, and bone cell analyses.

Results: MDA levels were significantly elevated across all groups (p = 0.007), particularly in the high-dose C. caudatus and vitamin C. However, trabecular bone ratio improved significantly in medium-dose Cosmos caudatus and vitamin C groups (p = 0.016).

Conclusion: These findings suggested that medium-dose C. caudatus supports bone integrity comparably to vitamin C and may exert osteoprotective effects beyond direct reactive oxygen species (ROS) scavenging, offering a potentially safer alternative for bone health under oxidative stress.

Purpose: Skeletal muscles have notable features that enable muscle hypertrophy in response to resistance training (RET). Most animal studies on ladder climbing have focused on the lower limb muscles; however, the movement also involves the upper limb muscles. Moreover, little evidence exists regarding whether RET affects food intake. Therefore, this study aimed to investigate RET-induced muscle hypertrophy in both the upper and lower limb muscles and to examine changes in food intake.

Methods: Twenty male Wistar Hannover rats (6 weeks old) were randomly assigned to sedentary control (SED, n = 10) or resistance training (RET, n = 10) groups during a 2-week acclimatization period. RET rats underwent the primary exercise training for 8 weeks, after 1 week of climbing adaptation, with a one-repetition maximum test. Body weight and food intake were monitored weekly. Twenty-four hours after the final training session, major muscles were dissected and weighed, and the flexor digitorum profundus (FDP) was analyzed using the cross-sectional area (CSA) of the myofibers.

Results: RET group showed significantly decreased final body weight and food intake compared to the SED group (p < 0.001). RET enhanced both muscle quantity (increased relative FDP muscle weight) and quality (improved muscle strength capacity and larger FDP myofibers).

Conclusion: Ladder-climbing RET induced hypertrophy in the upper limb FDP muscle rather than in other lower limb muscles despite decreases in body weight and food intake. Upper extremity strength training can provide benefits to healthy adults and individuals with limited lower extremity mobility.

Purpose: Evidence on the effects of low-grade dehydration on muscle function in non-athletic middle-aged adults is scarce and inconclusive. The objective was to assess the effect of small variations in hydration status due to 12-hour overnight fasting on right-leg muscle function in middle-aged adults.

Methods: Single-group before-and-after study in volunteers aged 35-65 years. Participants were assessed at two time points: after 12 hours of absolute fasting and after breakfast and drinking 1.5 L of water. Body composition and hydration status were assessed by bioelectrical impedance analysis (BIA) and muscle function by an isokinetic test.

Results: Fifty-nine volunteers (47 years, 81.4% women) were recruited. Under fasting conditions, total body water, intracellular water (ICW), and extracellular water were positively correlated with knee flexion and extension strength, work, and power in men and women. The ICW to fat-free mass ratio and phase angle were positively correlated with flexion and extension strength and work in women but not men. Flexion strength and work improved significantly after water intake in women but not men. No changes in muscle function were observed in individuals younger than 45 years. In those aged 45 years or older, significant differences were observed for flexion strength (58.7 vs 61.8 N, p = 0.004), work (269.0 vs 284.0 J, p = 0.003) and power (39.5 vs 41.3 W, p = 0.018).

Conclusion: Hydration status appears to have a role in muscle function, especially with increasing age. More studies, however, are required to better understand the influence of hydration on muscle function and the underlying mechanisms.

Purpose: This study aimed to develop a VO2peak-based framework for classifying exercise intensity in ICR mice and to validate the associated physiological responses.

Methods: Male ICR mice (8 weeks) completed four maximal graded exercise test (GXT) protocols (P1-P4) using a treadmill-equipped metabolic chamber. P1 and P2 began at 10 m/min with a fixed 15° incline, increasing speed by 3 m/min every 3 min (P1) or 1.5 m/min every 1.5 min (P2). P3 and P4 also started at 10 m/min but from a 0° incline; P3 increased both speed (3 m/min every 3 min) and incline (3° every 3 min), while P4 increased speed (1.5 m/min every 1.5 min) and incline (1.5° every 1.5 min) until 15°, after which only speed increments continued. VO2peak values were then used to calculate running speeds at 40%, 60%, and 80% VO2reserve to represent low, moderate, and high intensity, respectively. Constant-load tests (CXT) at these speeds measured metabolic responses and blood lactate concentrations.

Results: VO2peak did not differ significantly among protocols, but P4 showed greater variability. Target speeds were therefore determined from P1-P3. During CXT, oxygen consumption, energy expenditure, and VO2plateau rose with intensity, and blood lactate at 60% and 80% VO2reserve exceeded that at 40%, with 60% surpassing the 4 mM aerobic-anaerobic threshold.

Conclusion: These findings provide standardized VO2peak-based reference values for classifying exercise intensity in ICR mice. Fixed-incline GXT protocols reduce variability, and the derived speed thresholds can guide future exercise interventions.

Purpose: We conducted a cross-sectional study to clarify the workload of route salespeople in beverage sales for vending-machines in Japan. Specifically, we examined the volume of occupational physical activity (PA) as an objective measure of workload and physical pain as a subjective measure of workload, and assessed whether an association was observed between physical pain and the estimated number of years the employee wanted to continue to work.

Methods: Of 264 participants who engaged in route sales, thirty participants were asked to wear a triaxial accelerometer to measure PA during working hours, and 234 were observed for workload and physical pain using a questionnaire.

Results: The average occupational PA was 12,010 ± 3,160 steps/day, 2.45 ± 0.19 PA levels/day, and 507.5 ± 245.1 moderate to vigorous PA minutes/week. Half the participants reported lower back pain (LBP) and perceived a demanding workload. Participants who had LBP and had been with the company for more than 10 years perceived heavier workloads and estimated a shorter length of future service than those without LBP and more than 10 years in the company.

Conclusion: This study implies that route salespeople employed in the beverage vending machine industry are subjected to a high volume of physical activity and experience physical discomfort, particularly LBP. The nature of work involved in beverage sales for vending-machines necessitates a workload classification ranging from moderate-to-high based on both subjective and objective workload criteria.

Purpose: Machine learning methods accurately predict physical activity outcomes using accelerometer data generated by wearable devices. Thus, they allow investigation of the impact of the built environment on population physical activity. Although traditional machine learning methods do not provide prediction uncertainty, a new method, Bayesian Additive Regression Trees (BART), can quantify such uncertainty as a posterior predictive distribution. Our objective was to evaluate the performance of BART in regard to predicting physical activity status.

Methods: We applied multinomial BART and a benchmark method, random forest, to accelerometer data at 25,424 time points generated by wearable devices worn by 37 participants. We evaluated the prediction accuracy, F1 scores, and confusion matrices using leave-one-person-out cross-validation.

Results: BART and random forest demonstrated comparable prediction performances.

Conclusion: BART is a relatively novel machine learning method that can advance the incorporation of the predicted physical activity status into built environment research. Future research should evaluate the association between the environment and physical activity as predicted by BART.

Purpose: The objective of this study was to quantify daily physical activity levels in Korean older adults using accelerometers and establish sex- and age-specific normative percentile reference values for daily step counts.

Methods: A total of 375 community-dwelling older adults aged ≥ 65 years (182 males and 193 females) were enrolled. Physical activity was measured over one week using triaxial accelerometers. Participants were instructed to wear the device for ≥ 10 h per day on four or more valid days, including at least one weekend day. Normative percentile curve for step counts was estimated using a simple smoothing method after calculating sample quantiles by sex and age group by selecting a sample smoothing method.

Results: No significant differences in step counts were observed among older adults across the days of the week. Males had higher average step counts than females. At the 50th percentile, males aged 65-74 years recorded 8,272 steps/day, while those aged ≥ 75 recorded 7,634 steps/day; corresponding values for females were 6,631 and 5,706 steps/day, respectively, indicating a more pronounced decline in females than in males.

Conclusion: This study provides objective sex- and age-specific normative reference values for daily step counts in older Korean adults. These values can be used to evaluate physical activity levels, guide personalized goal setting, and inform national health promotion strategies for aging populations. The limitations of this study include its cross-sectional design and the potential underestimation of non-ambulatory activity by accelerometers.

Purpose: The World Health Organization (WHO) reported in 2016 that 81% of adolescents aged 11 to 17 years have insufficient physical activity (PA). This decline, coupled with poor nutrition and sedentary lifestyles, has emerged as a global concern. Regular PA is linked to better academic performance, motor skills, sleep, and stronger bones and muscles. Although most interventions to enhance PA in children are school-based, these have not effectively increased the overall daily PA. This review assesses the effectiveness of new devices such as electronic watches and smartphones in evaluating PA in older schoolchildren.

Methods: This review followed the Joanna Briggs Institute methodology. MEDLINE (PubMed) and Scopus were searched for articles. After removing duplicates, two reviewers independently screened the titles, abstracts, and full texts. Methodological quality was assessed using standardized tools, and data were extracted systematically.

Results: The search identified 2,259 articles, with 571 screened and 11 fully reviewed. Five studies were included, conducted in the USA, Namibia, Greece, Turkey, and Spain, involving adolescents averaging 13.8 years old. Three studies focused on self-reported tools, whereas two examined wearable monitors and smartphone apps. Waist-worn monitors displayed higher accuracy, whereas self-reported tools varied in validity and reliability.

Conclusion: Both traditional and new PA assessment tools have strengths and limitations. Waist-worn monitors generally provide higher accuracy, whereas self-reported tools can be reliable if properly calibrated. Continuous evaluation is essential for improving PA assessment in school-age children.

Purpose: Overweight and obesity contribute to the development of cardiovascular, neurocognitive, and metabolic diseases. One approach that has recently gained popularity in combating overweight and obesity is the consumption of energy or thermogenic beverages, owing to their proposed ability to boost metabolism and increase fat burning. However, whether Reign Storm Valencia Orange can exert positive effects remains unknown. This study hypothesized that consumption of Reign Storm Valencia Orange would acutely increase energy expenditure and fat utilization relative to water consumption.

Methods: Thirty-two individuals (17 females and 15 males) participated in this study. Arterial blood pressure, normalized oxygen consumption, resting energy expenditure (REE), and respiratory exchange ratio (RER) were assessed during rest at baseline and at 30, 60, 90, and 120 minutes after beverage consumption (randomized order).

Results: Arterial pressure was elevated following beverage consumption (main effect of time, p < 0.05), with no significant difference between the conditions (main effect of beverage, p > 0.15). Normalized oxygen consumption and REE were elevated following beverage consumption (main effect of time; p < 0.01 for both) with a significant interaction (p < 0.01 for both), indicating a greater impact of Reign Storm Valencia Orange. RER was reduced following beverage consumption (main effect of time; p < 0.0001), with a significant interaction (p < 0.0001), indicating a greater impact of the Reign Storm Valencia Orange condition. Consumption of Reign Storm Orange Valencia had a beneficial impact on indices of resting energy expenditure and metabolism and resulted in greater reliance on fats.

Conclusion: Accordingly, Reign Storm beverages, in combination with other modifiable lifestyle behaviors such as exercise and a healthy diet, can potentially assist in losing body weight and burning fat.

Purpose: To review the effects of amino acid supplementation including essential, branched-chain, and non-essential amino acids on muscle mass, strength, and adaptation, with a focus on sex-specific differences.

Methods: PubMed, ScienceDirect, and Google Scholar databases were searched for clinical and nonclinical studies on the effects of supplementation in adults, published between 1990 and 2025.

Results: Essential amino acids and leucine showed the most consistent associations with increased MPS and, in older adults, improvements in strength/lean mass. Branched-chain amino acids supplementation generally attenuated muscle damage/DOMS and helped preserve performance, with benefits appearing context dependent (e.g., energy restriction, high training load). Evidence for non-essential amino acids is preliminary. Signals of greater strength oriented effects in men and greater recovery benefits in women are biologically plausible but largely hypothesis-generating due to single sex cohorts and indirect cross study contrasts.

Conclusion: Amino acid supplementation can support muscle anabolism and, in selected contexts, strength and recovery, best viewed as an adjunct to resistance training with individualized dosing/timing. Progress requires adequately powered, pre registered, sex comparative RCTs that standardize protocols and prespecify functional and structural endpoints to define dose response, timing, and durability across ages and training states.