Physical Inactivity – A cause for increasing morbidity and mortality Non-communicable diseases have become a major epidemic in societies, rich and poor, developed and developing. This has occurred concurrently with modernization of lifestyle (Zimmet 1999). WHO estimates that lack of activity leads to more than 2 million deaths per year.

Physical Activity – A Miracle Drug Physical Activity is a miracle drug. Performed regularly on most days of the week, a dose of 30 to 45 minutes drastically reduces the risk of developing or dying from some of the leading causes of illness and death; and administers many health benefits.

Physical Activity – A successful route to weight loss Physical activity increases calorie burn: Weight loss results when calorie output exceeds calorie intake. Physical activity increases calorie output. It is not uncommon for a beginner exerciser to expend energy at the rate of 5 to 7 times above resting levels.(1) Further, active individuals have slightly higher resting metabolic rates than their sedentary counter parts (2), due to the re-synthesis of glycogen stores and repair of damaged tissues.(3) Hence, regular physical activity increases calorie burn, not only during an exercise bout, but whilst resting too.

Physical activity maintains metabolic rate: Preservation of fat-free mass (FFM) or lean body mass is important for maintenance of resting metabolic rate. When excess FFM is lost, metabolic rate dips and calorie output decreases. Exercise attenuates, but cannot totally prevent loss of FFM when weight loss occurs. Ballor and Poehlman conducted a meta-analysis to examine the effects of exercise training on preservation of FFM, during diet-induced weight loss. They found that 24% to 28% of weight loss came from FFM in the non-exercising dieter, whilst only 11% to 13% of weight loss came from FFM in the dieter who engaged in aerobic and resistance exercise.(4)

Dieting alone is not a solution for weight loss: When individuals restrict calorie intake drastically without exercising, initial rapid weight loss occurs due to loss of FFM. However, once metabolic rate dips, calorie output decreases and when this decrease matches the low calorie intake, weight plateaus. Also, lost weight is more likely to be regained when a normal eating pattern resumes, since low calorie fad diets do not introduce any positive behavioural or lifestyle changes.

Physical Activity – The other health benefits Research shows that regular physical activity also reduces the risk for several diseases and improves the overall quality of life. Lee et al followed 21,925 men, aged 30 to 83 for 8 years. They concluded that physical activity is very beneficial to overall health, even if no weight is lost.(5)

Physical Activity and Heart Disease Various studies have shown that physical inactivity is a risk factor for heart disease. Heart disease is almost twice as likely to develop in inactive people than in those who are active. In a study involving 40,000 women, slow walking for just an hour a week, cut the risk of heart disease in women in half.(6)

Investigators at the University of Minnesota, enrolled 675 sedentary people with normal cholesterol levels into a 20-week exercise program. At the end of 20 weeks, total cholesterol and LDL were unchanged, but the protective HDL levels had gone up an average of 3.6%. This improvement was consistent across race, gender and age. A study at the University of Southern California found that after 3 to 6 months of regular exercise, women reduced their total cholesterol by 5%, their LDL by 10% and raised their HDL by 17%. Another study has shown that though both step and traditional aerobics classes improved overall cholesterol, only steppers saw a rise in the “good” HDL cholesterol levels.(7)

Overall, daily physical activity can help prevent heart disease and stroke by strengthening the heart muscle, raising high-density lipoprotein (HDL) levels (good cholesterol), lowering low-density lipoprotein (LDL) levels (bad cholesterol), improving blood flow, and increasing the heart's working capacity. The best exercises to strengthen the heart and lungs are the aerobic ones like brisk walking, jogging, cycling and swimming.

Physical Activity and High Blood Pressure Exercise is a non-drug therapy for treating mild-to-moderate high blood pressure. Exercise, especially when combined with weight loss, can reduce blood pressure both at rest and in situations that typically increase blood pressure such as intensive physical activity and emotional distress.(8)

Physical Activity and Noninsulin-Dependent Diabetes By reducing body fat, physical activity can help prevent and control Type 2 or Non-Insulin Dependent Diabetes and the complications associated with it. Working muscles use glucose, thus exercise lowers blood sugar numbers naturally. Regular exercise also reduces the need for medication or insulin, by improving insulin sensitivity and glucose tolerance.

Physical Activity and Osteoporosis Regular moderate physical activity strengthens the bones by increasing its mineral content, thereby reducing the risk of developing osteoporosis later in life. A study conducted at the University of Florida has reported that high-intensity resistance training, three times a week, increased bone density especially in the femoral neck area. Low bone density in the femoral neck, is a major cause of fractures, disability and death in the elderly. Hence high-intensity resistance training can benefit the elderly. (9) New research also shows that if a pound of muscle is gained, bone strength increases three times more, than if a pound of fat was gained. Hence, exercise helps build not only muscle, but bone strength too.(10)

By lifting weights, loss of muscle that occurs with age or weight loss can be prevented. Weight bearing physical activity is also essential for normal skeletal development, during childhood and adolescence and for achieving peak bone mass in young adults.

Physical Activity and Cancer The link between physical activity and cancer prevention was confirmed in 1997, by a panel of 16 renowned scientists assembled by the American Institute for Cancer Research in conjunction with the World Cancer Research Fund. 4,500 scientific studies were reviewed and conclusions were published in a report - Food, Nutrition and the Prevention of Cancer: A Global Perspective. The panel concluded that eating a predominantly plant-based diet could reduce incidence of cancer by 20%; regular exercise and controlled weight brought the figure up to 40%.

There is convincing evidence that physical activity decreases the risk of colon, breast and lung cancer. Conversely, obesity, linked to inactivity, increases the risk of cancer of the kidney, endometrium, breast, bladder, colon and rectum.

Physical Activity and Aging A 30-year follow-up study of cardiovascular capacity, found that a 6-month endurance training program could reverse decades of decline in aerobic power, in middle-aged men, suggesting that it's never too late to start a fitness regimen.(11) Physical activity staves off the negative effects of aging because it helps maintain, improve and even repair the body.

Physical Activity and Back Pain By increasing muscle strength and endurance and improving flexibility and posture, regular exercise helps prevent back pain.

Physical Activity and Psychological Benefits Individuals who exercise regularly are less likely to be depressed, have a higher self-esteem, and have improved body image.(12) Regular exercise also reduces stress and anxiety.(13) Findings from a UK study suggest that an hour of aerobics can reduce tension, anger and fatigue, especially in individuals who felt depressed before the exercise bout.(14)

Physical Activity and Cognitive Skills A study conducted by Dr. Kisou Kubota of Nihon Fukushi University in Handa, Japan, has found that individuals consistently scored higher on intellectual tests after embarking on a running program. These improvements however, went down when the joggers stopped training. Hence, ongoing exercise is required to maintain the benefit. The link between physical activity and mental sharpness is unclear, but previous research suggests that maintaining a healthy flow of blood and oxygen protects the brain.

Researchers at Duke University in Durham, North Carolina, have reported that seniors who embarked on a 4-month exercise program showed significant improvement in memory and cognitive function.

Physical Activity – The Benefits are for Children too… According to researchers from Southern Cross Institute of Health Research in New South Wales, Australia, physically active children are not only healthier during their childhood, but may reap the benefits as they age. Physical activity, they explain, improves the strength of bones, lowers the risk of developing heart disease, type 2 diabetes, high blood pressure and boosts the immune system. (15)

Common Barriers to Physical Activity The 4 common barriers to regular physical activity are: lack of time, embarrassment of taking part in an activity, inability to exercise vigorously and lack of enjoyment of exercise. Of these, lack of time has consistently been reported as the greatest obstacle to being active. (16,17)

The Physical Activity Prescription … Studies show that even the most inactive people can gain significant health benefits, if they accumulate 30 minutes or more of physical activity per day. The American College of Sports Medicine (ACSM), the Centers for Disease Control and Prevention, the National Institute of Health, and the Surgeon General recommend 30 minutes or more of moderate-intensity physical activity on most or, preferably all days.(16,18, 19)

De Busk et al (20) have shown that three 10-minute bouts of aerobic exercise yield fitness improvements comparable to (though slightly less than) those from continuous 30-minute sessions. This may result in better adherence to workouts and increased weight loss. (21,22)

In Conclusion: Economic modernization has eliminated physical activity from our lives. Cars, elevators, escalators, televisions and computers, all a gift of industrialization, have transformed our population to a machine-driven one. Metabolically, we are hunters. Hence, in keeping with our heritage, exercise is a genetic imperative and must be restored in our daily lives, not only for weight loss, but for a myriad of other health benefits.
 

To Promote Physical Activity…