It's time to stop kidding yourself that the chores you do around the house and the occasional walk at the shopping moll are enough exercise for you. Cindy Ng, Senior Physiotherapist, Singapore General Hospital, kicks off this new column which underscores the importance of exercise and shows you just how to do it right. In this issue, she recommends resistance training to strengthen muscle and improve your glucose profile.

Many people assume that exercise and physical activity are the same. They think that doing housework or even walking up and down the workplace are all considered forms of exercise. That, however, is a myth.

Exercise is a sustained, continuous activity of a certain intensity level for at least 20 minutes. Unless one does housework without rest and at a moderate intensity, raising one's heart rate to at least 20 to 40 beats above rest for 20 minutes or does brisk walk non-stop at the workplace for 20 minutes, it cannot be called exercise.

For effective management of diabetes, lifestyle changes require one to engage in regular exercise. Regular means at least three times a week (alternate days). This is to sustain the benefits of exercise which are often lost within 48 hours.

It is well to walk around the park for 20 minutes daily, but that may not be optimal to increase one's insulin sensitivity such that the next visit to the doctor will reflect an improvement in Hba1c or fasting glucose level.

Patients with type 2 diabetes are at risk of premature coronary disease, particularly with concomitant hypertension, hyperinsulinemia, central obesity, and the overlap of metabolic abnormalities of hypertriglyceridemia, low HDL (high density lipoprotein), altered LDL (low density lipoprotein), and elevated FFA (free fatty acids).

Most studies show that these patients have a low level of aerobic fitness that is associated with many of the cardiovascular risk factors. Improvement in these risk factors has been linked to a decrease in plasma insulin levels, and it is likely that the beneficial effects of exercise on cardiovascular risk are related to improvements in insulin sensitivity.

Thus, it is important not only to be active, but also to exercise at the right level of intensity. Incorporating some resistance or weight training may strengthen the muscles as age-related decline in muscle mass will indirectly affect insulin sensitivity. This age-related decline might also explain the low exercise capacity of patients with type 2 diabetes mellitus (Guccione. 1993).

Resistance training can prevent such loss in muscle mass and may have benefits over and above aerobic training, which includes improving muscle strength and endurance, enhancing flexibility and body composition, decreasing risk factors for cardiovascular disease and improving glucose profile (Hurley & Roth. 2000).

Many studies on resistance training leading to a greater increase in insulin sensitivity were seen after several months of training and often attributed to an increase in glycogen storage (Colberg & Swain. 2000). However, many older adults are sceptical about weight training for fear of injuring themselves. It is important to be taught the correct posture or position either on the resistance machine or while carrying free weights to prevent injuries. The right amount of weights to be used when doing weight training, even as simple as biceps curls, is also important so as not to overload the joints, soft tissues around the joint as well as the muscles involved. The number of repetitions and the speed of movement when doing weight training are equally important as that will affect muscular strength, power and mass or size.

References:
1. Colberg SR & Swain DP. (2000). Exercise and diabetes control: A winning combination. The Physician and Sportsmedicine, 28(4).

2. Guccione AA. (1993). Geriatric Physical Therapy. (pp. 62 & 206-207). USA: Mosby.

3. Hurley BF & Roth SM. (2000). Strength training in the elderly: Effects on risk factors for age-related diseases. Sports Medicine. 30(4). 249-268.

Try these simple exercises to strengthen the big main muscles quadriceps, biceps and deltoids. Muscle strengthening and toning can increase muscle sensitivity towards insulin.