Arterial stiffening, hypertension and left ventricular (LV) remodelling are associated with increased risk of cardiovascular disease. Cardiorespiratory fitness is associated with cardiovascular function and reduced risk of cardiovascular disease. This cross-sectional study was carried out to determine the relationships between cardiorespiratory fitness, arterial stiffness, blood pressure (BP) and LV remodelling in women. On the basis of peak oxygen uptake, a total of 159 premenopausal (young) and postmenopausal (older) women were categorized into either low (unfit) or high (fit) cardiorespiratory fitness groups. The arterial stiffness and LV remodelling were measured by brachialankle pulse wave velocity (baPWV) and carotid augmentation index (AI) and LV relative wall thickness (RWT). Two-way analysis of variance indicated a significant interaction between age and cardiorespiratory fitness in baPWV, carotid AI, BP and RWT. In the older group, arterial stiffness (baPWV; 1401 ± 231 vs 1250 ± 125 cm s -1 , Po0.01, AI; 32.9±9.9 vs 24.8±10.1%, Po0.01), systolic blood pressure (SBP) (130 ± 22 vs 117 ± 15 mm Hg, Po0.01) and RWT (0.47 ± 0.08 vs 0.42±0.04, Po0.05) in fit women were lower than in unfit women. In older women, RWT was significantly related to baPWV (r ¼ 0.46, Po0.01), carotid AI (r ¼ 0.29, Po0.05), SBP (r ¼ 0.57, Po0.01) .V 2peak (r ¼ À0.32, Po0.05). In young women, they were not significant correlations, except for a weak correlation between RWT and SBP (r ¼ 0.21, Po0.05). These results suggest that higher cardiorespiratory fitness is associated with lower arterial stiffness, BP and RWT in older women.
The present study was designed to determine the effects of various levels of capsaicin (CAP) on endurance capacity in forty-nine male Sprague -Dawley rats, aged 4 weeks, which were assigned to four groups. Rats were given orally either control (0) or 6, 10 or 15 mg CAP/kg body weight 2 h before exercise by stomach intubations using a round-ended needle. The rats in each group were divided into two subgroups for resting or swimming exercise. Swimming exercise was performed with a weight corresponding to 3 % body weight attached to the tail, and endurance capacity was evaluated by swimming time to exhaustion. The highest dose (15 mg/kg) of CAP significantly (P, 0·05) increased endurance performance time and caused plasma non-esterified fatty acid to rise significantly by about 1·4-fold compared with that of non-CAP treated rats at exhaustion (P, 0·05). The highest dose of CAP had no effect on liver and gastrocnemius muscle glycogen (white and red) in resting rats, but significantly increased glycogen contents of both muscles at exhaustion (P,0·05). At rest, plasma noradrenalin levels of the rats receiving the highest dose were greater than that of non-CAP-treated rats and remained greater until exhaustion. The effects of CAP on endurance capacity have received little attention and have conveyed conflicting impressions. Kim et al. (1997) failed to show the maximal effect of 10 mg/kg doses of CAP on swimming endurance time in mice. The influences of various doses of CAP on endurance capacity were still unclear. Matsuo et al. (1996) reported that the intake of CAP have little sparing effect on glycogen in the liver and soleus muscles at rest and during exercise in rats previously fed a CAP-containing diet ad libitum for 1 week. Our present results suggest more than the highest dose of CAP (15 mg/kg) can cause the increase of endurance capacity, which might be induced through the sparing of muscle glycogen and the rise of non-esterfied fatty acids following the increase of circulating catecholamine.
This study was designed to determine whether combined treatments with genistein dosage and moderate resistance exercise would exhibit synergistically preventive effects on bone loss following the onset of menopause. Forty-one 12 wk-old female SD rats were assigned to five groups: 1) Sham operated (Sham); 2) ovariectomized (OVX-Cont); 3) OVX received genistein (OVX-GEN); 4) OVX exercised (OVX-EXE); and 5) OVX treated with both genistein and exercise (OVX-GEN-EXE). All rats were fed a low Ca (0.1%) diet ad libitum. Daily genistein dosage was 12 mg/kg body weight. Exercising rats took 40 sets of 1-min run interspersed with 1-min rest with a 100 g weight on the back on an uphill treadmill at 20 m/min. The experimental duration consisted of the adaptation and treatment periods of 4 weeks each. Uterine weight in OVX-Cont, OVX-GEN, OVX-EXE and OVX-GEN-EXE decreased to about 15% of that in Sham (p < 0.001). The femoral BMD (mg/cm2; mean +/- SE), assessed by DEXA (Lunar), of OVX-Cont was significantly lowered to 206 +/- 5 by -9%, as compared to 226 +/- 2 of Sham (p < 0.001). The BMD of OVX-GEN, OVX-EXE and OVX-GEN-EXE were 217 +/- 2, 217 +/- 2 and 222 +/- 2, respectively, and genistein dosage and resistance exercise equally increased the BMD of OVX rats by 5% (p < 0.01). Combined treatment of genistein and exercise more successfully recovered their decreased BMD by 8% (p < 0.001). BMD of the fourth lumbar vertebrae in OVX-Cont was declined to 191 +/- 7 by -15%, as compared to 225 +/- 4 in Sham (p < 0.001). OVX-EXE and OVX-GEN-EXE gained the BMD by 6% to 205 +/- 4 and 203 +/- 3, respectively, as compared to that of OVX-Cont (p < 0.01). These results suggest the possibility that the combined treatment of genistein dosage and resistance exercise have more beneficial effects by acting rather independently than their separate trials on the prevention of ovx-induced bone loss in femurs.
Background: An increase in bone mineral density during adolescence increases resistance to fractures in older age. The Korean Society for Bone and Mineral Research and the Korean Society of Exercise Physiology developed exercise guidelines to increase the peak bone mass (PBM) in adolescents based on evidence through a systematic review of previous research. Methods: Articles were selected using the systematic method, and the exercise guidelines were established by selecting key questions (KQs) and defining the effects of exercises based on evidence through a literature review for selecting the final exercise method. There were 9 KQs. An online search was conducted on articles published since 2000, and 93 articles were identified. Results: An increase in PBM in adolescence was effective for preventing osteoporosis and fractures in older age. Exercise programs as part of vigorous physical activity (VPA) including resistance and impact exercise at least 5 to 6 months were effective for improving PBM in adolescents. It is recommended that resistance exercise is performed 10 to 12 rep•set-1 1-2 set•region-1 and 3 days•week-1 using the large muscles. For impact exercises such as jumping, it is recommended that the exercise is performed at least 50 jumps•min-1 , 10 min•day-1 and 2 days•week-1. Conclusions: Exercise guidelines were successfully developed, and they recommend at least 5 to 6 months of VPA, which includes both resistance and impact exercises. With the development of exercise guidelines, the incidence of osteoporosis and fractures in the aging society can be reduced in the future, thus contributing to improved public health.
SummaryWe investigated the effects of two carbohydrate-based sports drinks on fluid intake and immunoendocrine responses to cycling. Six well-trained male cyclists completed trials on three separate days that involved cycling at 60% V · O2peak for 90 min in hot conditions (28.161.5˚C and 52.663.1% relative humidity). During each trial, the subjects consumed ad libitum (1) an isotonic sports drink (osmolality 317 mOsm/kg), (2) . Blood glucose concentration was significantly higher at the end of the isotonic and hypotonic drink trials compared with the water trial. Neutrophil count and the plasma concentrations of catecholamines, interleukin 6 (IL-6), myeloperoxidase, calprotectin and myoglobin increased significantly during all three trials. IL-6 and calprotectin were significantly lower following the hypotonic drink trial compared with the water trial. In conclusion, hypotonic sports drinks are appealing for athletes to drink during exercise, and may help to offset fluid losses and attenuate some inflammatory responses to exercise.
SummaryThe influences of various doses of capsaicin on endurance capacity remain to be clarified. The purpose of this study was to determine whether or not capsaicin delays stored tissue glycogen depletion. Rats were orally given either a vehicle or a dose of cap saicin, 6, 10, or 1.5mg/kg of body weight, 2h before exercise. The rats in each group were divided into three subgroups for resting and swimming exercise (30min, exhaustion). Swimming exercises were performed with a weight corresponding to 3% body weight at tached to the tail, and the endurance capacity was evaluated by the swimming time until exhaustion. The 15mg/kg dose of capsaicin significantly (p<0.05) enhanced the en durance performance time and plasma concentration of epinephrine, norepinephrine, free fatty acid and glucose rose to significantly higher levels within 30min; swimming exercise compared to rest (p<0.05). At the 15mg/kg capsaicin dosage, the plasma insulin level de creased to significantly lower levels in group subjected to 30-min swimming as compared to the resting group (p<0.05), while plasma glucagon rose to a significantly higher level (p<0.05). Liver and gastrocnemius muscle glycogen in the group subjected to 30-min swimming was maintained at significantly higher concentrations in the rats fed 15mg/kg of capsaicin as compared to the vehicle counterparts (p<0.05). These results suggest that the improvement in swimming endurance with the high capsaicin dosage is caused by an increase in fatty acid utilization as the energy source, resulting in the sparing of glycogen.
Low energy availability (EA) can impair physiological function in athletes. The purpose of this study was to investigate EA status, metabolic status, and bone metabolism with biochemical analysis in Korean male soccer players. Twelve male athletes (18–20 years) completed the study. Body composition and bone mineral density were measured using dual energy X-ray absorptiometry (DXA), while VO2 max was determined by an incremental exercise test. Blood samples were taken for bone marker and hormone analyses. Resting energy expenditure (REE) was measured using the Douglas bag method and predicted using the DXA method. Food diaries and heart rates (HR) during training were recorded, and the Profile of Mood States 2 and Eating Attitude Test 26 were completed. Group differences between low EA (LEA <30 kcal/kg FFM/d, n = 5) and high EA (HEA ≥30 kcal/kg FFM/d, n = 7) were evaluated. The mean EA of the all participants was 31.9 ± 9.8 kcal/kg FFM/d with only two participants having an EA above 45 kcal/kg FFM/d. LEA showed suppressed REE (LEA: 26.0 ± 1.7 kcal/kg/d, HEA: 28.8 ± 1.4 kcal/kg/d, p = .011) with a lower REEratio (LEA: 0.91 ± 0.06, HEA: 1.01 ± 0.05, p = .008) as well as a lower insulin-like growth factor 1 (IGF-1) level (LEA: 248.6 ± 51.2 ng/mL, HEA: 318.9 ± 43.4 ng/mL, p = .028) compared to HEA. There were no group differences in bone markers or other hormone levels. Korean male athletes exhibited low EA status with suppressed metabolism, but there was limited evidence on the effect of EA on bone metabolism, endocrine system, and psychological parameters.
[Purpose]This study was performed to assess the effects of high-intensity intermittent swimming training(HIT) on bone in ovariectomized rats.[Methods]Six-week-old female Sprague-Dawley rats were randomly assigned to either sham operation or bilateral ovariectomy. After surgery, they were divided into the following four groups: 1) sham-operated sedentary (S), 2) sham-operated exercise training (SE), 3) OVX sedentary (O), 4) OVX exercise training (OE) 5) OVX given 17β-estradiol (OE2) and 6) OVX exercise training and given 17β-estradiol (OEE). SE, OE and OEE rats were used extremely high-intensity swim exercise. The rats repeated fourteen 20-s swimming bouts with a weight equivalent to 14, 15, and 16% of body weight for the first 5, the next 9, and the last 5 days, respectively. Between exercise bouts, a 10-s pause was allowed. HIT was originally designed as an exercise method; a method that very quickly induces an increase in the maximum oxygen intake (Tabata I et al., 1996). OEE and OE2 rats were subcutaneously injected ethanol with 25μg/kg body weight 17β-estradiol 3 times per week.[Results]Bone strength, bone mineral density and trabecular bone parameters were measured after a 8-weeks experimental period. Bone strength was significantly higher in the SE, OE, OE2 and OEE group compared with the O group. BV/TV was significant increase in the SE, OE groups compared with the O group. BMD showed no difference in the OE group compared with the O group.[Conclusion]This study demonstrate some beneficial effects of postmenopausal osteoporosis of high-intensity intermittent swimming training on bone structure and strength.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
334 Leonard St
Brooklyn, NY 11211
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.