This study investigated the effects of sleep deprivation on heart rate variability (HRV), blood pressure (BP), fasting blood glucose (FBG), and endothelial function as well as the immediate effects of 4‐7‐8 breathing control on HRV and BP. In total, 43 healthy participants aged 19–25 years were classified into two groups: Twenty two in the with sleep deprivation group and 21 in the without sleep deprivation (control) group. Resting heart rate (HR), BP, HRV, FBG, and endothelial function were examined. Subsequently, participants practiced 4‐7‐8 breathing control for six cycles/set for three sets interspersed between each set by 1‐min normal breathing. Thereafter, the HR, BP, and HRV were immediately examined. The HRV, HR, and BP variables and FBG were not significantly different between the two groups. However, endothelial function was significantly lower in the sleep deprivation group than that in the control group (p < 0.05). In response to 4‐7‐8 breathing control, low‐ and very‐low‐frequency powers significantly decreased (p < 0.05), whereas high‐frequency power significantly increased (p < 0.05) in the control group. Moreover, time domain, total power, and very‐low‐frequency power significantly decreased (p < 0.05) in the sleep deprivation group. Both groups had significantly decreased HR and systolic BP (p < 0.05). HRV, HR, and BP variables showed no significant differences between the groups. Healthy young adults with and without sleep deprivation may have similar HRV, BP, and FBG values. However, sleep deprivation may cause decreased endothelial function. Furthermore, 4‐7‐8 breathing control can help participants improve their HRV and BP, particularly in those without sleep deprivation.

Chest wall expansion determines lung volume and functional capacity. Factors determining chest wall expansion include respiratory muscle strength. Accordingly, there may be association among respiratory muscle strength, chest wall expansion, and functional capacity. Thusly, this cross-sectional study identified the relationship between respirato-ry muscle strength, chest wall expansion, and functional capacity. Seventy-six healthy male and female participants aged between 20 to 59 years exhibiting a body mass index of 18.5 to 22.9 kg/m² were enrolled. Inspiratory and expiratory muscle strength were evaluated via maximum inspiratory pressure (MIP) and maximum expiratory pressure (MEP), respectively. Chest wall expansion was measured through thoracic circumferences at three different levels; upper, middle, and lower levels with diaphragmatic movement also measured utilizing the circumference of the lower edge of the 10th rib. Functional capacity was evaluated through distance obtained from a 6-min walk test. Results showed that both MIP and MEP were significantly correlated with chest wall expansion at the middle (P=0.005 and P=0.006) and lower (P=0.012 and P=0.020) thoracic levels as well as diaphragmatic movement (both P<0.001). Moreover, both MIP and MEP were significantly related amid the 6-min walk distance (P=0.025 and P<0.001). In conclusion, respiratory muscle strength is positively associated with chest wall expansion, diaphragmatic movement, and functional capacity in healthy participants.

It is documented that regular exercise is beneficial for improving the antioxidant system, metabolic system, cardiac autonomic function, and blood pressure in those with hypertension. In this regard, low‐intensity exercise is recommended for older adults, particularly those with chronic diseases. This study aimed to compare the effects of long‐term regular continuous walking with intermittent walking on oxidative stress, metabolic profile, heart rate variability, and blood pressure in older adults with hypertension. Forty‐three participants with hypertension aged 60–80 years were randomly divided into the continuous or intermittent walking (CON or INT) groups. Participants in the CON group walked for 30 min, 3 days/week for 12 weeks. Participants in the INT group split 30 min walking into 3 identical sessions punctuated by a 1 min rest after each session, 3 days/week for 12 weeks. Antioxidant and oxidative stress markers, metabolic markers, heart rate variability, and blood pressure were evaluated before and after the exercise program. Glutathione (GSH), GSH to GSH disulfide (GSSG) ratio, and total GSH increased significantly, and GSSG and malondialdehyde decreased significantly in both groups (p < 0.05) without significant differences between groups. Triglycerides, ratio of total cholesterol to high‐density lipoprotein cholesterol, and atherosclerogenic index were significantly lower in the CON group than those in the INT group (p < 0.05). The standard deviation of the NN intervals and root mean square of the successive differences were significantly higher, and low‐frequency power was significantly lower in the INT group than that in the CON group (p < 0.05). No significant changes in blood pressure were noted in both groups, and nor were there any significant differences between groups. Long‐term regular continuous and intermittent walking may comparably increase antioxidants, reduce oxidative stress, and be beneficial for improving important blood pressure‐related outcomes, including metabolic profile or cardiac autonomic function in older adults with hypertension.

This study was carried out to evaluate sensitivity, specificity, and test cutoff score to predict cardiorespiratory fitness by using the 2-min step test (2MST) in patients with type 2 diabetes mellites (DM). The associa-tion of the 2MST and physical fitness tests including a 6-min walk test (6MWT), a 5 time sit-to-stand test (FTSST), and leg strength in the form of a leg performance test were also investigated. This study was cross-sectional and conducted in 100 type 2 DM patients. Patients were screened through health questionnaires, medical illness, general char-acteristics, and physical fitness tests; 2MST, 6MWT, FTSST, and leg strength. Blood was collected for assessment of fasting blood sugar and lipid profiles. The number of steps in the 2MST was positively cor-related with the distance of the 6MWT (r=0.6995, p<0.0001) and leg strength (r=0.4292, p<0.0001). 2MST was negatively correlated with time to perform the FTSST (r=-0.405, p<0.0001). Moreover, this study established the optimal cutoff score of the 2MST at ≤61 steps with 92.24% sensitivity, and 81.36% specificity to predict cardiorespiratory fitness in type 2 DM patients. Our findings indicate that the 2MST may be used as a predictor for walking capacity, leg strength, and ability to change position from sitting to standing in type 2 DM. In addition, this result may imply that patients with type 2 DM performing the 2MST at less than 61 steps was significantly associated with decreased cardio-respiratory fitness.

Highly-intensive exercise occurs in reactive oxygen species which leads to cellular damage as a result of increased oxidative stress markers. An appropriate program design incorporating volume, intensity, and types of exercise may produce different effects amid oxidative status in athletes. Therefore, this study aimed to investigate the outcomes of resistance training (RT) and high-intensity interval training (HIIT) on oxidative stress markers, and physical performance in university athlete subjects. The effect of two different protocol types (RT and HIIT) on oxidative stress and antioxidant status were also compared. Seventy-two university athletes, were recruited and divided into control, RT, and HIIT groups (n=22/group). The RT group were undertaken a resistance exercise training program of the upper and lower body. The HIIT group performed their exercise training on a cycle ergometer. The training program was 30 min/day, 3 days/wk, continuously over 8 weeks. We observed that long-term RT and HIIT improved blood glutathione and glutathione disulfide redox ratio in all athletes. The results demonstrated that only RT training significantly decreased plasma malondialdehyde. Another finding was that RT and HIIT resulted in similar elicitation of physical performance in the post-compared with pretraining exercise. This study revealed that RT and HIIT programs improved antioxidants and physical performance in university sports athletes. However, oxidative markers were only improved following the RT program. This study suggests that RT program is superior to HIIT in improving oxidative stress markers in sport athletes.

Oxidative stress has been suggested to play a role in the pathogenesis of chronic obstructive pulmonary disease (COPD). This study aimed to investigate a link between malondialdehyde (MDA) levels, pulmonary function, and cardiac autonomic control in patients with COPD. Plasma levels of MDA, heart rate variability, and pulmonary function were measured in 50 clinically stable COPD patients and 50 normal male controls. COPD patients exhibited lower means of the standard deviations of all normal to normal (NN) intervals (SDNN), the square root of the mean of the sum of the squares of differences between adjacent NN intervals (RMSSD), and high frequency (HF). Nevertheless, they presented greater low frequency (LF) and low frequency/high frequency ratio (LF/HF ratio) in supine and head-up tilt positions than controls (P< 0.001). Moreover, a negative correlation between MDA levels with SDNN (P< 0.001) and a positive correlation with LF (P< 0.01) and LF/HF ratio (P< 0.05) were observed in both positions. In COPD patients, plasma MDA levels were 2.3 times greater than controls (4.33± 2.03 µM vs. 1.89± 0.39 µM, P< 0.001), and they were inversely correlated with forced vital capacity, forced expiratory volume in 1 sec, midexpiratory flow, and peak expiratory flow (P< 0.001). Our findings suggest a potential role for oxidative stress in impaired cardiac autonomic control and clinical relevance of plasma MDA levels as a predictor of severity of COPD in COPD patients.