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Exercise as it relates to Disease/Type 2 diabetes and resistance exercise

What is Type 2 Diabetes Mellitus?Edit

Normal metabolic function of the body requires insulin to regulate glucose levels through uptake in skeletal muscle and suppression of production in the liver.[1] Homeostasis is disturbed in Type 2 Diabetes Mellitus (T2DM) often as a result of sedentary lifestyle, old age and possible genetic predispotition.[2] The disease can be characterised by insulin insensitivity and high blood glucose, with the potential to progress to insulin dependency. The 2007-08 National Health Survey found that over 3.8% of the Australian population suffers from T2DM, although actual figures may differ due to the nature of self-reported data.[3] With the incidence of T2DM on the rise, current research has uncovered evidence to suggest that resistance exercise may be helpful in combating the disease.

Why should Type 2 Diabetics participate in resistance exercise?Edit

Exercise, diet and medication play an important role in the management of type 2 diabetes.[4] Traditionally, aerobic exercise has been prescribed to patients with type 2 diabetes as it has been associated with weight loss, improved glucose tolerance and cardiovascular fitness.[4] Recent research has found that resistance exercise is also effective at improving diabetes management and is comparable to aerobic exercise.[5]

Findings include;

  • Reduction in HbA1c levels [6]
  • Increased glucose uptake by muscles [7]
  • Improved fasting blood glucose [5][7]
  • Improved insulin resistance [4][5][7][8]
  • Improved muscle glycogen store [7]
  • Decreased medications [7]
  • Increased muscle mass [6][9]
  • Decrease in insulin levels [7]

Small, but significant reduction in HbA1c levels have been found in diabetics after completing resistance exercise regimes. A 1% decrease in HbA1c is associated with a 37% decrease in micro vascular disease and a 21% decrease in risk of diabetes-related death, showing that resistance exercise is important in the management of type 2 diabetes.[6]

Is it safe?Edit

Much has been written about the safety of resistance exercise for type 2 diabetics because of various co-morbidities that exist such as hypertension and cardiovascular disease.[6] However, research has found that high-intensity resistance exercise elicits the same blood pressure response as daily activities such as climbing stairs or carrying groceries.[10] In fact, most research has found that the only adverse effect of resistance training is muscle soreness and that it is safe form of exercise even for patients with a high risk of cardiac events.[6][7] Patients with severe diabetic retinopathy should not do resistance exercise because of the increased risk of retinal detachment.[10] As with any exercise program, medical advice and clearance should be sought before commencement and there should be adequate supervision.

Are there any other benefits?Edit

Resistance exercise significantly increases muscle mass and fat-free mass compared to aerobic exercise.[6] This leads to;

  • Decreased abdominal obesity [4]
  • Decreased systolic blood pressure [7][10]
  • Increased renal function [10]
  • Increased muscle strength [6][9]
  • Decreased triglycerides [7]

Resistance exercise also leads to an increase in daily physical activity.[7] Patients with arthritis or lung disease may also find that resistance exercise is easier to do than aerobic exercise.[6] Increased muscle strength also helps to reduce the risk of falls in the elderly.[4]

RecommendationsEdit

All training should be under initial supervision by a qualified exercise specialist to ensure minimal risk of injury and maximal health benefits. Additionally, some insulin-dependant patients may find it necessary to alter insulin dose prior to exercise, and should be discussed with a doctor before undertaking any new exercise programs.[11] Recommendations from the American Diabetes Association for a resistance training program are listed below.[10] A progressive resistance training (PRT) model should be followed to achieve this target program, whereby frequency, intensity and time are increased over a specified period.[9]

Frequency 2-3 times per week
Intensity 3 sets of 8-10 reps at 50-80% 1RM (30-60secs rest between sets)
Time 30-45min sessions
Type Target all major muscle groups. Can include weights, resistance bands, bodyweight

It is important to remember that resistance exercise should be part of a treatment plan that also incorporates;[11]

  • Not smoking
  • Regular physical activity
  • Maintaining a healthy weight
  • Making healthy food choices
  • Managing blood pressure and cholesterol levels

Further readingEdit

ReferencesEdit

  1. Kim, J., Wei, Y. & Sowers, J. (2008). Role of Mitochondrial Dysfunction in Insulin Resistance. Circulation Research, 102,401-414.
  2. Ritov, V. et al. (2009). Deficiency of electron transport chain in human skeletal muscle mitochondria in type 2 diabetes. Am J Physiol Endocrinol Metab, 298, 49-58.
  3. Diabetes. (2011). Retrieved October 22, 2011, from AIHW http://www.aihw.gov.au/diabetes/
  4. a b c d e Dunstan, D., Daly, R., Owen, N., Jolley, D., De Courten, M., Shaw, J., & Zimmet, P. (2002). High-Intensity Resistance Training Improves Glycemic Control in older Patients With Type 2 Diabetes. Diabetes Care, 25(10), 1729-1736.
  5. a b c Eves, N., & Plotnikoff, R. (2006). Resistance Training and Type 2 Diabetes. Diabetes Care, 29(8), 1933-1940.
  6. a b c d e f g h Irvine, C., & Taylor, N. (2009). Progressive resistance exercise improves glycaemic control in people with type 2 diabetes mellitus: a systematic review. Australian Journal of Physiotherapy, 55, 237-246.
  7. a b c d e f g h i j Castaneda, C., Layne, J., Munoz-Orains, L., Gordon, P., Walsmith, J., Foldvari, M., Nelson, M. (2002). A Randomized Controlled Trial of Resistance Exercise Training to Improve Glycemic Control on Older Adults with Type 2 Diabetes. Diabetes Care, 25(12), 2335-2341.
  8. Fenicchia, L., Kanaley, J., Azevedo, J., Miller, C., Weinstock, R., Carhart, R., & Ploutz-Synder, L. (2004). Influence of Resistance Exercise Training on Glucose Control in Women With Type 2 Diabetes. Metabolism, 53(3), 284-289. http://www.portalsaudebrasil.com/artigospsb/diab104.pdf
  9. a b c Ibanez, J., Izquierdo, M., Arguelles, I., Forga, L., Larrion, J., Garcia-Unciti, M., Gorostiaga, E. (2005). Twice-Weekly Progressive resistnace Training Decreases Abdominal Fat ans Improves Insulin Sensitivty in Older Men With Type 2 Diabetes. Diabetes Care, 28(3), 662-667
  10. a b c d e Sigal, R., Kenny, G., Wasserman, D., Castaneda-Sceppa, C., & White, R. (2006). Physical Activity/Exercise and Type 2 Diabetes. Diabetes Care, 29(6), 1433-1438.
  11. a b Type 2 Diabetes. (2011, September 7). Retrieved October 22, 2011, from Diabetes Australia http://www.diabetesaustralia.com.au/en/Understanding-Diabetes/What-is-Diabetes/Type-2-Diabetes/