Brisk walking improves endurance fitness without changing body fatness in previously sedentary women

Summary

The purpose of this study was to examine the influence of brisk walking on endurance fitness and the amount and distribution of body fat in previously sedentary women. Twenty eight women [mean age (SEM): 44.9 (1.5) years] followed the walking programme for 1 year, whilst 16 acted as controls [age 44.4 (2.3) years]. Changes in endurance fitness were evaluated by measuring the oxygen uptake ($\dot VO_2$) at a reference blood lactate concentration of 2 mmol · 1⁻¹ . Two 1.61-km field tests of walking were completed, one at maximal speed and one at a “brisk” speed, as well as a 1.61-km walk on a motorised treadmill. The amount and distribution of body fat was determined by hydrostatic weighing and anthropometry and energy intake was evaluated using the 7-day weighed food intake method. Walkers completed an average of 157 min·week⁻¹ of brisk walking over the year. The following were increased in walkers, relative to controls: brisk walking speed [walkers 1.73 (0.05) m·s⁻¹ vs 1.88 (0.07) m·s {−1}; controls 1.69 (0.05) m·s⁻¹ vs 1.70 (0.05) m · s −1 at baseline and 12 months respectively,P<0.01], maximal walking speed and$\dot VO_2$ at 2 mmol·1⁻¹. In addition, brisk walking reduced heart rate and blood lactate concentration during stepping as well as during standard, submaximal treadmill walking. It did not modify either the amount or the distribution of body fat, despite an unchanged energy intake.