Objective: To compare the effects of counseling alone with that of additional participation in supervised training courses on exercise capacity in patients with impaired fasting glucose.
Design: Randomized, controlled intervention trial using a nested cohort approach.
Setting: Primary care centers in western Austria.
Patients: Thirty-six patients with impaired fasting glucose (16 males, 20 females; mean age, 57.5 +/- 6.9 years).
Interventions: Participants of both groups were instructed about the preventive effectiveness of changing their lifestyle, especially losing weight and increasing physical activity. One group had additionally been offered supervised, progressive, individually tailored aerobic exercise programs for 1 hour twice a week.
Main outcome measures: Changes in the levels of exercise capacity, body mass, and fasting blood glucose.
Results: The subjects with supervised exercise participated in this program for 1.8 hours (+/- 0.3) per week over 12 months. Supervised exercise was sufficient to maintain exercise capacity, whereas counseling alone was not (+4.4% versus -6.9%; P = 0.01). After the 12-month intervention period, body mass was reduced in the supervised exercise group (-3.0%) compared with the counseling alone group (+1.0%) (P = 0.03) and fasting plasma glucose levels had similarly improved by counseling for adequate lifestyle changes alone (-8.2%) and in combination with supervised exercise (-6.0%).
Conclusion: In contrast to counseling alone, 2 sessions of supervised training per week, besides the self-chosen physical activity and nutritional measures, are sufficient to maintain exercise capacity in patients with impaired fasting glucose.