Exercise, Calories & Weight Control
Weight Study Aim
To examine whether restriction of caloric intake and exercise of vigorous
intensity can independently and additively influence clinic and ambulatory
blood pressures in sedentary overweight men.
Weight Study Design
Sixty subjects aged 20-50 years were randomly allocated either to continue
their normal caloric intake or to restrict it by 4186-6279 kl/day, with
15 percent provided by protein, 30 percent by fat and 55 percent by carbohydrate,
for 16 weeks. Within each of these groups subjects were further randomly
allocated either to a control light intensity programme of exercise or
to a vigorous intensity programme of exercise for 30 min three times a
week. The light exercise group performed stationary cycling against no
resistance, flexibility exercises and slow walking. The vigorous intensity
group cycled on an ergometer at 60-70 percent of maximum their workload.
Weight Study Results
Fifty-one subjects completed the study. Their maximal oxygen uptake was
increased by approximately 24 percent with vigorous exercise but did not
change with light exercise. Caloric intake restriction led to a significant
loss of body mass of 9.5 kg (95 percent confidence interval 7.6-11.3),
whereas vigorous exercise had no effect. Restriction of caloric intake
reduced supine clinic systolic and diastolic blood pressures significantly
by 5.6 (2.3-8.9) and 2.4 mmHg (0.4-4.2), respectively. Relative to the
control light exercise group, exercise of vigorous intensity exercise
had no significant effect on clinic blood pressure. In contrast, time
series analysis revealed that both caloric intake restriction and vigorous
exercise were associated with lower daytime ambulatory systolic blood
pressure, the reduction in systolic blood pressure being sustained throughout
the 24 h period when vigorous exercise and caloric intake restriction
were combined.
Weight Study Conclusion
Compared with the effects of caloric intake restriction, the effects of
a vigorous exercise programme on blood pressure are inconsistent, there
being no influence on clinic blood pressure but a reduction in daytime
ambulatory blood pressure. However, when combined with caloric intake
restriction, regular vigorous exercise exhibits a synergistic effect in
reducing ambulatory blood pressure throughout a 24 hour period.
Source: Cox KL, Puddey IB, Morton AR, Burke
V, Beilin LJ, McAleer M. Department of Human Movement, University of Western
Australia. 1996
Return to Weight
Loss Research Articles
|
|
|
com