ABSTRACT
The purpose of this study was to determine the influence of a 6-month unsupervised, flexible and fairly light intensity walking program on endurance fitness, strength, lipids and lipoproteins and bone health in a group of middle-aged sedentary women. Six pre-menopausal and 8 post-menopausal women, aged 54 yr, served as the walk training group (W) and 9 women (2 post-menopausal), aged 49yr, served as controls (C) . W walked an average of 10, 000 steps per day for 6 months, which included an average of 5, 000 steps of brisk walking for 30 min, 4 to 5 days per week. Workloads, heart rates and double-product break point (during incremental maximal ergometer exercise), body weight and %fat, serum lipids, leg strength and bone density (by ultrasound) and induces of bone metabolism were measured at baseline and after 3 and 6 months. Walk training in W resulted in a significant improvement in maximal workload during the exercise test compared with C. Double product break point in W during exercise significantly shifted towards higher workloads and resting heart rate was reduced. Isokinetic muscular strength of leg extensors and abdominal muscular endurance measured by situps were also significantly increased in W. Estimated calcaneal bone density showed a tendency to increase after 6 months of training in W. Indicators of bone resorption and growth remained unchanged. Changes in serum lipids and lipoproteins were also favorable, but not significant. In conclusion, these results show that a flexible and self-regulated walking program is sufficient to elicit improvements in cardiovascular endurance, aerobic capacity measured by DPBP and strength of leg and abdominal muscles. Bone strength and serum lipids were not clearly improved after 6 months with this walking program. If training time were extended to 12 months, significant improvements in these measures can be expected because tendencies toward improvements were observed.
ABSTRACT
The purpose of this study was to detemine the effect of water intake on themoregulatory response during a round of golf (18 holes) in the heat (30-33°C, 55-70% RH) . Ten middle-aged male subjects participated in two separate golf rounds. During the first round the subjects played without fluid replacement (D), while in the second they received water replacement equal to weight loss in D (R) . With D, body weight loss of 3.8% was accompanied by a 13.3% reduction in calculated plasma volume (PV), while a small loss of body weight (0.5%) with an increase in PV of 4.6% was observed in R. A third round of golf by 5 of the subjects in cooler weather (20.4°C) without fluid replacement two months later resulted in heart rate and rectal temperature changes only slightly lower than during R. Golfing with D significantly elevated rectal temperatures and heart rates as compared to R. The rectal temperatures and heart rates at end of the 4.5-hr rounds were 39.4°C and 145 bpm, and 38.6°C and 116 bpm, in D and R, respectively. The serum enzymes, aspaartate aminotransferase, alamine aminotransferase, lactate dehydrogenase, and creatine kinase were measured at rest and after golfing. All enzyme levels increased signijicantly after golfing in D and to a lesser extent in R. The advantages of frequent fluid replacement during golf in high environmental temperatures was clearly demonstrated.