Role of Exercise in Type 2 DM

Role of Exercise in Type 2 DM

Physiology DepartmentMedical Faculty

Universitas Sumatera Utara

• Exercise plays an important role in glycemic control for people with type 2 diabetes.

• The major problem of type 2 diabetes is the lack of target cell response to insulin (insulin resistance)

• Insulin resistance; inadequate utilization of insulin by the cells in the insulin-responsive tissues of the body, including muscle

• Because the cells become resistant to insulin, the hormone can not perform its function of facilitating glucose transport across the cell membrane

• Research has shown that the number or availability of insulin receptors increases during exercise, increasing body’s sensitivity to insulin

• Muscle contraction has an insulin-like effect. Membrane permeability to glucose increases with muscular contraction, possibly due to an increase in the number of glucose transporters associated with the plasma membrane

• The primary benefits of exercise are:– Reducing blood glucose– Reducing blood cholesterol– Reducing triacylglycerol– Reducing body fat– Improve cardiovascular function

Prescription of Exercise for Health and Fitness

Physiology DepartmentMedical Faculty

Universitas Sumatera Utara

How to start exercise programs?

• Active lifestyle is important for optimal health• Maintain a regular regimen of activity, that is

of longer duration or of more vigorous intensity are likely to derive greater benefit

• Appropriate exercise type and intensity varies, depending on individual characteristics, current fitness level, and specific health concerns

Medical clearance/evaluation

• Medical evaluation necessary before starting an exercise program

• Some people either should not be exercising at all or are considered at high risk and should be restricted to exercising only under close medical supervision:– men over 40 years age– Women over 50 years age– People of any age who are considered to be high risk

Exercise prescription

• Involves four basic factors:– Mode or type of exercise– Frequency of participation– Duration of each exercise bout– Intensity of the exercise bout

• The goal of exercise program is to improve aerobic capacity in people who have not been exercising

Exercise and Rehabilitation of People With Diseases

• Exercise training has become an extremely important part of rehabilitation programs for a number of diseases

• Although the specific physiological mechanisms explaining the benefits of exercise training for some diseases have not been clearly defined, there are many general health benefits that appear to improve the patient’s prognosis

Cardiovascular Adaptations to Training

►► Cardiorespiratory endurance refers to your body’s ability to sustain prolonged, rhytmical exercise. It is highly related to your aerobic development.

►► Most sport scientists regard VO2max – the highest rate of oxygen onsumption obtained during maximal or exhaustive exercise – to be the best indicator of cardiorespiratory endurance.

►►Cardiac output represents how much blood leaves the heart each minute, whereas a-vO2 diff indicates how much oxygen is extracted from the blood by the tissues. The product of these values tells us the

rate of oxygen consumption: VO2 = SV a-vO2 diff.

►►Of the chambers of the heart, the left ventricle changes the most in response to endurance training

► The internal dimensions of the left ventricle increase, mostly in response to an increase in ventricular filling.

► Left ventricular thickness also increases, increasing the strength potential of chamber’s contractions.

► Following endurance training, stroke volume increases during rest, submaximal exercises, and maximal exertion.

► A major factor leading to the stroke volume increases is an increased end-diastolic volume, probably caused by an increase in blood plasma and greater diastolic filling time

► Another major factor is increased left ventricular contractility. This is caused by hypertrophy of the cardiac muscle and increased elastic recoil, which results from increased stretching of the chamber with more diastolic filling.

► Blood flow to muscles is increased by endurance training.

Increased capilarization. Greater opening of existing capillaries. More effective blood redistribution. Increased blood volume.

► Increased blood flow results from four factors: