SINGAPORE - Activities that involve high impact, such as jumping, hopping, running and contact sports, are not the best thing for people with diabetes.
This is because their feet are more susceptible to injuries and infections due to poor blood circulation, reduced sensitivity to pain and poor wound healing, said Dr Joan Khoo, a consultant endocrinologist at Changi General Hospital (CGH) and director of the CGH Diabetes Centre.
For a long time, brisk walking was the exercise most recommended for controlling blood sugar and improving the results of the haemoglobin A1c (HbA1c) test, an indicator of overall glucose control over the past three months, said Mr Ray Loh, an exercise physiologist at the Sports Medicine and Surgery Clinic at Tan Tock Seng Hospital.
However, recent studies have found that resistance training (including weight lifting) gives similar results and is especially beneficial for those with leg and knee problems who have difficulty walking longer distances, he said.
But the best results are seen in patients who combine cardio and resistance training - such as better HbA1c results and insulin sensitivity - as compared to doing either cardio or resistance training alone.
One study has shown that when compared with healthy individuals, those with diabetes have a lower proportion of Glut4 in red muscle fibres.
However, no significant difference in this glucose transporter for white muscle fibres was found between healthy and diabetic individuals.
Mr Loh shared that Glut4 is a protein located deep in our muscle and fat cells which acts as a glucose transporter to increase the rate of glucose absorption into the cells.
According to the American Council on Exercise, red muscle fibres specialise in long-duration, lower-intensity movement, such as walking, standing or lifting loads below 70 per cent of a person's maximum ability.
Red muscle fibres tyre slowly and make up most of the muscle composition in the body.
White muscle fibres create higher-intensity actions lasting fewer than 30 seconds, such as jumping and lifting loads greater than 70 per cent of a person's maximum ability.
The way to increase the amount of the glucose transporter protein is to build up muscle mass.
Proper resistance training can help to build muscle mass more effectively than just doing cardio exercises, which do not build up muscle mass effectively.
A greater amount of muscle mass increases the amount of Glut4 which helps in the overall rate of glucose absorption, said Mr Loh.
This is important as the glucose transporter protein allows sugar to be taken into the muscle cells without the need for insulin.
But which exercises to do is different for each person.
A person's exercise regimen needs to be customised - targeting the right intensity for different muscle types to produce optimal results in blood sugar control and insulin sensitivity, said Mr Loh.
WHAT IS EXERCISE?
Exercise is a physical activity but not all physical activity is exercise, said Mr Loh.
For example, home chores such as mopping the floor and gardening are physical activities while brisk walking and playing badminton are exercises.
"I prefer to classify exercise as a more structured and planned physical activity with a target or aim to improve physical fitness or health," he added.
A structured and planned physical activity should be strong enough to challenge your body for improvement and yet safe enough not to risk injury or overtraining.
Thus, pre-exercise consultation with a sports physician is very important in order to programme an optimal exercise regimen based on a person's current physical condition and fitness, said Mr Loh.
"No one exercise programme is suitable for all."
EXERCISES TO AVOID
Exercises that might increase the risk of complications should be avoided.
1. People with peripheral neuropathy, in which there is damage to the nerves of the limbs and body, should avoid exercises that may cause trauma to the feet, as well as exercises that involve balancing and jumping, such as jogging, hiking and walking on uneven surfaces.
"The feet should always be kept clean and dry," said Mr Loh
2. People with end-stage kidney disease should not do exercises that increase the blood pressure, such as weight lifting and high intensity training.
3. People with retinopathy - damaged blood vessels in the eyes - should avoid vigorous and high intensity exercise such as weight lifting, overhead lifting and exercises which involve lowering or sudden movements of the head, for example, yoga and pilates.
4. People with hypertension should avoid heavy weight lifting, power exercises and exercises which involve holding the breath.
WHAT TO DO
Other than cardiovascular exercise, which raises the heart rate and should be done at least three days a week for at least 150 minutes in total, there should also be resistance exercises worked into the exercise programme.
Do more if weight loss is desired, with no more than two rest days per week between each session, said Dr Khoo.
Two to three sessions a week of resistance exercise is recommended to further reduce blood sugar and body fat and increase cardiovascular fitness, she said.
Mr Loh recommends cardio and resistance training on separate days.
If time is limited, you can divide resistance training into three to four smaller sessions, targeting different body regions or muscle groups per session, he said.
Always start with a regimen that is of manageable intensity and increase it by no more than 10 per cent a week.
Making progress by increasing the exercise load or intensity is important as exercise needs to be challenging.
"Only when our body is challenged, will it change and improve," he said.
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