Appropriate physical activity and dietary intake achieve optimal metabolic control in older type 2 diabetes patients.

AIMS/INTRODUCTION: The aim of the present study was to investigate an appropriate level of physical activity and optimal dietary intake in older type 2 diabetes patients. MATERIALS AND METHODS: The cross-sectional study enrolled 210 older type 2 diabetes patients. Participants were interviewed to obtain information on physical activity, 24-h dietary recall and typical weekly dietary patterns. Anthropometric measurements, and biochemical analysis of blood and urine were determined. RESULTS: Moderate physical activity (either moderate leisure-time physical activity or moderate physical activity level) and diet with protein intake of ≥0.8 g/kg/day were associated with lower glycated hemoglobin and triglyceride, higher high-density lipoprotein, lower waist circumference, body mass index and body fat, as well as better serum magnesium and albumin levels in older diabetic patients. In contrast, inadequate protein intake was correlated with higher glycated hemoglobin, triglyceride, body fat percentage, waist circumference and body mass index. In addition, high physical activity with inadequate protein and magnesium intake might exacerbate magnesium deficiency, resulting in poor glycemic control in older diabetic patients. Furthermore, low physical activity and inadequate protein intake were linked with poor glycemic control, and lower high-density lipoprotein, and higher triglyceride, body fat percentage, waist circumference and body mass index. CONCLUSIONS: Moderate physical activity and adequate dietary protein intake (≥0.8 g/kg/day) might be the optimal recommendation for better metabolic control in older adults with type 2 diabetes.

Effect of short-term heat acclimation on endurance time and skin blood flow in trained athletes.

BACKGROUND: To examine whether short-term, ie, five daily sessions, vigorous dynamic cycling exercise and heat exposure could achieve heat acclimation in trained athletes and the effect of heat acclimation on cutaneous blood flow in the active and nonactive limb. METHODS: Fourteen male badminton and table tennis athletes (age = 19.6 ± 1.2 years) were randomized into a heat acclimation (EXP, n = 7) or nonheat acclimation (CON, n = 7) group. For 5 consecutive days, the EXP group was trained using an upright leg cycle ergometer in a hot environment (38.4°C ± 0.4°C), while the CON group trained in a thermoneutral environment (24.1°C ± 0.3°C). For both groups, the training intensity and duration increased from a work rate of 10% below ventilatory threshold (VT) and 25 minutes per session on day 1, to 10% above VT and 45 minutes per session on day 5. Subjects performed two incremental leg cycle exercise tests to exhaustion at baseline and post-training in both hot and thermoneutral conditions. Study outcome measurements include: maximum oxygen uptake (VO2max); exercise heart rate (HR); O2 pulse; exercise time to exhaustion (tmax); skin blood flow in the upper arm (SkBFa) and quadriceps (SkBFq); and mean skin (Tsk). RESULTS: The significant heat-acclimated outcome measurements obtained during high-intensity leg cycling exercise in the high ambient environment are: (1) 56%-100% reduction in cutaneous blood flow to the active limbs during leg cycling exercise; (2) 28% drop in cutaneous blood flow in nonactive limbs at peak work rate; (3) 5%-10% reduction in heart rate (HR); (4) 10% increase in maximal O2 pulse; and (5) 6.6% increase in tmax. CONCLUSION: Heat acclimation can be achieved with five sessions of high-intensity cycling exercise in the heat in trained athletes, and redistribution of cutaneous blood flow in the skin and exercising muscle, and enhanced cardiovascular adaptations provide the heat-acclimated athletes with the capability to increase their endurance time in the hot environment.

The effect of eight weeks of supplementation with Eleutherococcus senticosus on endurance capacity and metabolism in human.

The aim of this study was to examine the effects of Eleutherococcus senticosus (ES) supplementation on endurance capacity, cardiovascular functions and metabolism of recreationally trained males for 8 weeks. Nine recreationally trained males in college consumed 800 mg/d of ES or starch placebo (P) for 8 weeks according to a double-blind, randomized, placebo controlled and crossover design with a washout period of 4 weeks between the cycling trials. Subjects cycled at 75% VO2 peak until exhaustion. The examined physiological variables included endurance time, maximal heart rate during exhaustion exercise, VO2, rating of perceived exertion and respiratory exchange ratio. The biochemical variables including the plasma free fatty acid (FFA) and glucose were measured at rest, 15 min, 30 min and exhaustion. The major finding of this study was the VO2 peak of the subjects elevated 12% (P < 0.05), endurance time improved 23% (P < 0.05) and the highest heart rate increased 4% (P < 0.05) significantly. The second finding was at 30 min of 75% VO2 peak cycling, the production of plasma FFA was increased and the glucose level was decreased both significantly (P < 0.05) over 8-week ES supplementation. This is the first well-conducted study that shows that 8-week ES supplementation enhances endurance capacity, elevates cardiovascular functions and alters the metabolism for sparing glycogen in recreationally trained males.

L-Arginine attenuates xanthine oxidase and myeloperoxidase activities in hearts of rats during exhaustive exercise.

The present study was to investigate the effects of l-arginine (l-Arg) supplementation on cardiac oxidative stress and the inflammatory response in rats following acute exhaustive exercise on a treadmill. Rats were randomly divided into four groups: sedentary control (SC); SC with l-Arg treatment (SC+Arg); exhaustive exercise (E); exhaustive exercise with l-Arg treatment (E+Arg). Rats in groups SC+Arg and E+Arg received a 2 % l-Arg diet. Rats in groups E and E+Arg performed an exhaustive running test on a treadmill at a final speed of 30 m/min, 10 % grade, at approximately 70-75 % VO2max. The results showed a significant increase in cardiac xanthine oxidase (XO) and myeloperoxidase activities and membrane lipid peroxidation endproduct (malondialdehyde; MDA) levels of exercised rats compared with SC rats. The increased cardiac XO activity and MDA levels in exercised rats were significantly decreased in exercised rats supplemented with l-Arg. Myocardial GSSG content increased whereas the GSH:GSSG ratio was depressed in exercised rats compared with SC rats. Cardiac GSSG levels significantly decreased, whereas total glutathione, GSH and the GSH:GSSG ratio increased in exercised rats supplemented with l-Arg compared with exercised rats. The activities of creatinine kinase (CK) and lactate dehydrogenase (LDH), and lactate, uric acid, and nitrite and nitrate levels in the plasma significantly increased in exercised rats compared with SC rats. The activities of plasma CK and LDH were significantly decreased in l-Arg-supplemented plus exercised rats compared with exercised rats. These findings suggest that l-Arg supplementation reduces the oxidative damage and inflammatory response on the myocardium caused by exhaustive exercise in rats.

Protective effects of L-arginine on pulmonary oxidative stress and antioxidant defenses during exhaustive exercise in rats.

AIM: To assess the effects of L-arginine (L-Arg) supplementation on pulmonary oxidative stress and antioxidant defenses in rats after exhaustive exercise. METHODS: Rats were randomly divided into four groups: sedentary control (SC), sedentary control with L-Arg treatment (SC+Arg), exhaustive exercise with control diet (E) and exhaustive exercise with L-Arg treatment (E+Arg). Rats in groups SC+Arg and E+Arg received a 2% L-Arg diet. Rats in groups E and E+Arg underwent an exhaustive running test on a motorized treadmill. Pulmonary oxidative stress indices [xanthine oxidase (XO), myeloperoxidase (MPO), and malondialdehyde (MDA)] and antioxidant defense systems [superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), glutathione reductase (GR), and glutathione (GSH)] were investigated in this study. RESULTS: L-Arg supplementation significantly reduced exercise-induced elevations of XO and MPO activities in lung. L-Arg reversed the exercise-induced increase in SOD and GR activities, but increased CAT and GPX activities. L-Arg administration also significantly increased the GSH levels in plasma. CONCLUSION: L-Arg supplementation can prevent elevations of XO and MPO activities in the lung and favorably influence pulmonary antioxidant defense systems after exhaustive exercise.

Effect of postexercise carbohydrate supplementation on glucose uptake-associated gene expression in the human skeletal muscle.

We previously found that the exercise-induced elevation in GLUT4 mRNA of rat muscle can be rapidly down-regulated when glucose is given immediately following exercise. The purpose of this study was to determine the effect of postexercise carbohydrate diet on GLUT4 and hexokinase (HK) II mRNA levels in the human skeletal muscle. Eight untrained male subjects (age, 20.7+/-3.1 years) exercised for 60 min on a cycle ergometer at a 70-75% maximal oxygen consumption. The postexercise dietary treatment was performed in a crossover design. Immediately after the exercise, a diet with 70% carbohydrate content (1 g per kilogram of body weight; 356+/-19.8 kcal) was given to half of the subjects (eaten in 10 min) followed by a 3-h recovery, while the control subjects remained unfed for 3 h. Biopsies were performed on the deep portion of the vastus lateralis muscle of all subjects immediately after the exercise and 3 h after the carbohydrate ingestion. Blood glucose and serum insulin concentrations were measured every 30 min for 3 h. At the end of the 3-h recovery, blood glucose and serum insulin levels were not different from control levels, indicating that the oral carbohydrate was mostly disposed in the body within 3 h. In addition, GLUT4 and HK II mRNA levels were significantly lowered in the exercised human skeletal muscle in subjects receiving the carbohydrate diet. In conclusion, the present study demonstrates that GLUT4 mRNA and HK II mRNA in the exercised human skeletal muscle were significantly lowered by a high-carbohydrate diet.