THE INFLUENCE OF A 1-YEAR PROGRAM OF BRISK WALKING ON ENDURANCE FITNESS AND BODY-COMPOSITION IN PREVIOUSLY SEDENTARY MEN AGED 42-59 YEARS

This study examined the influence of a 1-year brisk walking programme on endurance fitness and the amount and distribution of body fat in a group of formerly sedentary men. Seventy-two males, aged 42-59 years, body mass index 25.2 (0.3) kg.m(-2) [mean (SEM)], were randomly alloca ted to either a walking; group (n = 48) or control group (n = 24). Bri sk walking speed was evaluated using a 1.6-km track walk. Changes in e ndurance fitness were assessed by measuring blood lactate concentratio n and heart rate during submaximal treadmill walking. Body composition was determined by hydrostatic weighing and anthropometry; energy inta ke was assessed from 7-day weighed food inventories. Differences in th e response of walkers and controls were, examined using two-way analys es of variance. Forty-two walkers (87.5%) completed the study and aver aged 27.9 (1.4) min.day(-1) of brisk walking (range 11-46). Brisk walk ing speed averaged 1.95 (0.03) m.s(-1) and elicited approximately 68 ( 1) % of maximum heart rate. Heart rate and blood lactate concentration during submaximal treadmill walking were significantly reduced in the walkers after 3, 6 and 12 months and the oxygen uptake at a reference blood lactate concentration of 2 mmol.l(-1) was increased by 3.2 ml.k g(-1).min(-1) (14.9%) in the walkers at 6 months (P<0.01). Although sk infold thicknesses at anterior thigh and medial calf sites decreased s ignificantly for the walkers, the response of the two groups did not d iffer significantly for other body composition variables or for energy intake.