Background: Systematically evaluate the effects of structured exercise and behavioral intervention (physical activity [PA] alone/PA + diet) on long-term PA in type 2 diabetes. Methods: Systematic search of 11 databases (inception to March, 2017). Randomized controlled trials investigating structured exercise/behavioral interventions in type 2 diabetes reporting PA outcomes ≥6 months were selected. Results: Among 107,797 citations retrieved, 23 randomized controlled trials (including 18 behavioral programs and 5 structured exercise) met inclusion criteria (n = 9640, 43.6% men, age = 60.0 (4.0) y). All structured exercise trials demonstrated increased objective PA outcomes relative to control (pooling was inappropriate; I 2 = 92%). Of 18 behavioral interventions, 10 increased PA significantly, with effect sizes ranging from 0.2 to 6.6 (pooling was inappropriate; I 2 = 96%). After removing 1 outlier, the remaining 17 studies significantly improved PA (pooled effect size = 0.34), although smaller compared with structured exercise. After removing the outlier, meta-regression also revealed significant direct relationships between total contacts (r = .50, P < .01) and more face-to-face counseling (r = .75, P < .001) and increased PA. However, long-term changes in PA and HbA1c were not related. Conclusion: Both structured exercise and behavioral interventions increased PA in type 2 diabetes, although effect sizes were larger for supervised exercise. The effectiveness of behavioral programs was improved when delivery included more extensive and face-to-face contact.
Marjan Mosalman Haghighi, Yorgi Mavros and Maria A. Fiatarone Singh
Birinder Singh B. Cheema, Marissa Lassere, Ronald Shnier and Maria A. Fiatarone Singh
The purpose of this article is to document a rotator cuff tear sustained by an elderly woman performing progressive resistance training (PRT) in a recent randomized controlled clinical trial. The patient was a sedentary 73-y-old Caucasian woman. Investigation revealed an acute, full-thickness tear of the right supraspinatus secondary to performing a shoulder press exercise. Further investigation via MRI revealed degenerative disease of the acromioclavicular joint including lateral downsloping of the acromion and an anteroinferior acromial spur, which would presdispose to impingement. Conservative management was implemented in this case for over 6 months with minimal success. The patient remained functionally limited in virtually all activities of daily living. Given the medical history, health status, physical condition, and age of our patient, it is probable that degenerative changes predisposed the patient to the injury. To our knowledge this is the first published report of an older adult sustaining a rotator cuff tear during PRT.
Nathan J. de Vos, Nalin A. Singh, Dale A. Ross, Theodora M. Stavrinos, Rhonda Orr and Maria A. Fiatarone Singh
To determine the effect of training intensity on the contributions of force and velocity to improvements in peak power (PP) after explosive resistance training in older adults.
112 healthy older adults (69 ± 6 yr) were randomized to explosive resistance training at 20% (G20), 50% (G50), or 80% (G80) maximal strength (1-repetition maximum) for 8–12 wk (twice weekly, 5 exercises, 3 sets of 8 explosive concentric/slow eccentric repetitions) using pneumatic resistance machines or a nontraining control group (CON).
Force at peak power (FPP) increased significantly and similarly among training groups compared with CON. Velocity at peak power (VPP) did not improve significantly and remained similar between all groups. Force contributed significantly more to PP production in G80 and G50 than in CON. The change in PP was independently predicted by changes in fat-free mass in G80 and by changes in both FPP and VPP in G50 and G20.
Explosive resistance training in older adults results in the ability to produce higher PP outputs with heavier loads without loss of movement velocity. Moderate- to high-intensity training induced a greater relative contribution of force to PP production in this cohort.
Olivier Seynnes, Olivier A. Hue, Frédéric Garrandes, Serge S. Colson, Pierre L. Bernard, Patrick Legros and Maria A. Fiatarone Singh
The relationship between isometric force control and functional performance is unknown. Submaximal steadiness and accuracy were measured during a constant force-matching task at 50% of maximal isometric voluntary contraction (MVC) of the knee extensors in 19 older women (70–89 years). Other variables included MVC, rate of torque development, and EMG activity. Functional performance was assessed during maximal performance of walking endurance, chair rising, and stair climbing. Isometric steadiness (but not accuracy) was found to independently predict chair-rise time and stair-climbing power and explained more variance in these tasks than any other variable. Walking endurance was related to muscle strength but not steadiness. These results suggest that steadiness is an independent predictor of brief, stressful functional-performance tasks in older women with mild functional impairment. Thus, improving steadiness might help reduce functional limitations or disability in older adults.
Michelle M. Porter, Miriam E. Nelson, Maria A. Fiatarone Singh, Jennifer E. Layne, Christine M. Morganti, Isaiah Trice, Christina D. Economos, Ronenn Roubenoff and William J. Evans
Resistance training (RT) increases strength in older adults, but there have been few studies of long-term RT or detraining in older adults. Postmenopausal participants (51–71 years of age) were randomized to RT or a control group for Year 1. For Year 2, participants chose whether to resistance train or not. Three groups emerged: train/train (n = 8: 60 ± 4 years), train/no train (n = 11: 62 ± 3 years), or controls (n = 17; 58 ± 6 years). Both training groups increased strength (p < .05) in Year 1. In Year 2, train/train maintained strength, whereas train/no train lost strength for knee extension (p < .001) but not for arm pulldown. Controls did not change. Reported physical activity levels were significantly increased in trainers in Year 1 and remained high regardless of RT in Year 2 (p < .05). Therefore, sustained changes in strength and physical activity behavior might be possible even if RT is discontinued.