ACSM POSITION STAND: TYPE 2 DIABETES & EXERCISE
Albright et al., 2000
• • Physical activity is an underutilised therapy Favourable changes in glucose tolerance and insulin sensitivity usually deteriorate within 72 h of the last exercise session: consequently, regular physical activity is imperative to sustain glucose-lowering effects and improved insulin sensitivity Individuals with type 2 diabetes should strive to achieve a minimum cumulative total of 1,000 kcal per week from physical activities Due to general lower level of fitness (VO2max) than non-diabetic individuals and exercise intensity should be at a comfortable level (RPE 10-12) in the initial periods of training and should progress cautiously as tolerance for activity improves Resistance training has the potential to improve muscle strength and endurance, enhance flexibility and body composition, decrease risk factors for cardiovascular disease, and result in improved glucose tolerance and insulin sensitivity Modifications to exercise type and/or intensity may be necessary for those who have complications of diabetes
Maiorana, A., O'Driscoll, G., Cheetham, C., Dembo, L., Stanton, K., Goodman, C., Taylor, R. and Green, D. (2001). The effect of combined aerobic and resistance exercise training on vascular function in type 2 diabetes. Journal of the American College of Cardiology, 38, 3, 860-6.
AIMS, RATIONALE AND HYPOTHESES
The authors clearly state the aims and rationale: Aim • The purpose of the study was to identify whether exercise improved vascular resistance and conduit function in patients with type 2 diabetes mellitus Rationale • Exercise is often recommended for patients with type 2 diabetes to improve physical conditioning and glycemic control • Up until this time period no study has found exercise to aid patients suffering from endothelial dysfunction associated with type 2 diabetes • No other study at this time had investigated both conduit and resistance vessel function, and exercise The authors however, do not outline the hypotheses of the study
METHODOLOGY AND EXPERIMENTAL DESIGN
• Concise logical and chronological summary of the precise methodology employed to undertake the study without difficulty Adequate methodology for aims Before and after either eight weeks of exercise training using a randomised crossover design: • Resistance vessel function analysed via strain gauge plethysmography following infusion of acetylcholine (ACh) and sodium nitroprusside (SNP)
Conduit vessel function analysed via high-resolution ultrasound and flowmediated dilation of the brachial artery; dilation via glyceryl trinitrate (GTN) was also explored
Participants • Sixteen patients (14 men, 2 women), aged 52±2 (SE) years, were recruited. Medications were not altered during the course of the trial
METHODOLOGY AND EXPERIMENTAL DESIGN
Controls • • • • • • Assessments always carried out same time of day after medication for patients No use of caffeine/alcohol 12 hours pre-assessment Assessment conditions kept constant Equipment setup and placement, and participant preparation kept the same throughout Where possible, machines were used to reduce human error and improve precision Randomised crossover design used – untrained vs trained
As one arm was tested other arm served as control
Key results: • Significant increase in flow-mediated dilation from 1.7 6 ± 0.5% to 5.0 6 ± 0.4% following training (P < 0.001). Endothelium-dependent vasodilation was enhanced in both conduit and resistance vessels, the forearm blood flow ratio to ACh was significantly improved (P < 0.05). Responses to SNP and GTN were unchanged Significantly improved glycemic control indices of
• • • Generally well organised presentation of the key data and statistical analyses In the study presented data supports interpretations Interestingly, in terms of forearm blood flow no difference was found when...
References: Albright, A., Franz, M., Hornsby, G., Kriska, A., Marrero, D., Ullrich, I., & Verity, L. S. (2000). American College of Sports Medicine position stand. Exercise and type 2 diabetes. Medicine and Science in Sports and Exercise, 32, 7, 1345. Boulé, N. G., Kenny, G. P., Haddad, E., Wells, G. A., & Sigal, R. J. (2003). Meta-analysis of the effect of structured exercise training on cardiorespiratory fitness in Type 2 diabetes mellitus. Diabetologia, 46, 8, 1071-81.
Church, T. S., Blair, S. N., Cocreham, S., Johannsen, N., Johnson, W., Kramer, K., et al., (2010). Effects of aerobic and resistance training on hemoglobin A1c levels in patients with type 2 diabetes. JAMA: the journal of the American Medical Association, 304(20), 2253-2262.
Eves, N. D., & Plotnikoff, R. C. (2006). Resistance training and type 2 diabetes: Considerations for implementation at the population level. Diabetes Care, 29, 8, 1933-41. Green, D. J., Maiorana, A., O 'Driscoll, G., & Taylor, R. (2004). Effect of exercise training on endothelium-derived nitric oxide function in humans. The Journal of Physiology, 561, 1-25.
Hansen, D., Dendale, P., Jonkers, R. A., Beelen, M., Manders, R. J., Corluy, L., Mullens, A., et al. (2009). Continuous low- to moderate-intensity exercise training is as effective as moderate- to high-intensity exercise training at lowering blood HbA1c in obese type 2 diabetes patients. Diabetologia, 52, 9, 1789-97.
Maiorana, A., O 'Driscoll, G., Cheetham, C., Dembo, L., Stanton, K., Goodman, C., Taylor, R. and Green, D. (2001). The effect of combined aerobic and resistance exercise training on vascular function in type 2 diabetes. Journal of the American College of Cardiology, 38, 3, 860-6. Perri, M. G., Anton, S. D., Durning, P. E., Ketterson, T. U., Sydeman, S. J., Berlant, N. E.,. et al.,(2002). Adherence to exercise prescriptions: effects of prescribing moderate versus higher levels of intensity and frequency. Health Psychology, 21, 5, 452.
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