Exercise and improved insulin sensitivity in older women: evidence of the enduring benefits of higher intensity training

• Published in: Journal of applied physiology (1985) 2006-01, Vol.100 (1), p.142-149
• Main Authors: DiPietro, Loretta, Dziura, James, Yeckel, Catherine W, Neufer, P. Darrell
• Format: Article
• Language: English
• Subjects: Adaptation, Physiological - physiology; Aged; Aged, 80 and over; Biological and medical sciences; Body Composition - physiology; Exercise; Exercise - physiology; Exercise Test; Exercise Therapy - methods; Female; Fundamental and applied biological sciences. Psychology; Humans; Insulin; Insulin - blood; Insulin Resistance - physiology; Middle Aged; Older people; Oxygen Consumption - physiology; Physical Exertion - physiology; Physical fitness; Physical Fitness - physiology; Sensitivity; Treatment Outcome; Women
• ISSN: 8750-7587; 1522-1601
• DOI: 10.1152/japplphysiol.00474.2005

1 The John B. Pierce Laboratory, and the Departments of 2 Epidemiology and Public Health, 3 Internal Medicine, and 4 Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut Submitted 25 April 2005 ; accepted in final form 29 August 2005 Few studies have compared the relative benefits of moderate- vs. higher intensity exercise training on improving insulin sensitivity in older people while holding exercise volume constant. Healthy older (73 ± 10 yr) women ( N = 25) who were inactive, but not obese, were randomized into one of three training programs (9-mo duration): 1 ) high-intensity [80% peak aerobic capacity ( O 2 peak ); T H ] aerobic training; 2 ) moderate-intensity (65% O 2 peak ; T M ) aerobic training; or 3 ) low-intensity (stretching) placebo control (50% O 2 peak ; C TB ). Importantly, exercise volume (300 kcal/session) was held constant for subjects in both the T H and the T M groups. O 2 peak was determined by using a graded exercise challenge on a treadmill. Total body fat and lean mass were determined with dual-energy X-ray absorptiometry. The rate of insulin-stimulated glucose utilization as well as the suppression of lipolysis were determined 72 h after the final exercise bout by using a two-step euglycemic-hyperinsulinemic clamp. We observed improved glucose utilization at the higher insulin dose with training, but these improvements were statistically significant only in the T H (21%; P = 0.02) compared with the T M (16%; P = 0.17) and C TB (8%; P = 0.37) groups and were observed without changes in either body composition or O 2 peak . Likewise in the T H group, we detected a significant improvement in insulin-stimulated suppression (%) of adipose tissue lipolysis at the low-insulin dose (38–55%, P < 0.05). Our findings suggest that long-term higher intensity exercise training provides more enduring benefits to insulin action compared with moderate- or low-intensity exercise, likely due to greater transient effects. elderly; endurance training; diabetes Address for reprint requests and other correspondence: L. Di Pietro, The John B. Pierce Laboratory, 290 Congress Ave., New Haven, CT 06519 (e-mail: ldipietro{at}jbpierce.org )