TYPES OF PHYSICAL ACTIVITIES  

Resistance Exercise – Resistance training consists of various exercises that focus on developing strength and increasing muscle mass.^1–3 It usually involves the use of either external weights or body weight to overload skeletal muscles, using movements that “resist” weight. Resistance training is the primary exercise used to increase muscle. Bicep curls, deadlift, bench press, squats, pushups, sit-ups, lunges, and planks are examples of resistance exercises.

Aerobic Exercise – Aerobic exercise is a type of physical activity that can be maintained continuously and utilizes large muscle groups that rely on aerobic metabolism.⁴ Unlike resistance exercises that emphasize muscle growth and strength, aerobic exercises focuses on improving cardiorespiratory fitness.⁵ Examples include walking, jogging, long distance running, swimming, dancing, hiking, and cycling, among others.

PHYSICAL ACTIVITY & HEART HEALTH

Physical inactivity is one of the greatest risk factors for cardiovascular diseases (CVDs; ie, diseases of the heart and blood vessels).⁶ Aerobic exercises as well as high intensity interval training and resistance/strength training are all recommended for improving cardiovascular health.⁷ Aerobic exercises have mainly been the focus of cardiovascular health, shown to improve cardiorespiratory fitness over time.⁴ Various studies have demonstrated that regularly engaging in aerobic exercises can prevent and treat hypertension (ie, high blood pressure) and CVDs.^7,8 For instance, a meta-analyses of 21 prospective studies including over 650,000 adults concluded that high levels of leisure time physical activity was associated with lowered risk of coronary heart disease and stroke by 20-30% in men and 10-20% in women.⁹ Physical activity is also thought to improve cardiac output, lower the risk of obesity, and improve glycemic control, all important factors in determining cardiovascular health. Evidence also suggests that resistance training can prevent decline in skeletal muscle mass, increase energy expenditure, and improve obesity, diabetes, and hypertension, which are risk factors of CVD.¹⁰

PHYSICAL ACTIVITY & OBESITY

Obesity is a chronic disease that is defined as a body mass index (BMI) greater than 30 kg/m².¹¹ Along with excess consumption of food, a sedentary lifestyle and low amounts of physical activity are key risk factors and causes of obesity.¹²

Major organizations recommend physical activity and eating a healthy diet as being crucial parts of any weight loss intervention.^13,14 Studies show that in addition to its role in weight loss, physical activity has an important function in preventing weight regain after successful weight loss.¹⁴ Physical activity is associated with long-term weight loss and moderate weight regain, allowing maintenance or even gain of muscle mass that help metabolism as well as allowing the consumption of more calories without significantly affecting total energy consumption.¹⁵ Additionally, numerous metabolic benefits are found to be associated with physical activity independent of weight loss or changes in BMI.^14,16,17 Epidemiological studies show that physical activity is associated with increased muscle mass, improved cardiorespiratory fitness, and decreased risk of CVD. Physical activity is also shown to improve biomarkers in individuals with obesity, including decreased arterial stiffness, improved insulin sensitivity, decreases in hemoglobin (Hb) A1C, and improved lipid profiles. Studies have also observed that physical activity can transition metabolically unhealthy obese phenotypes into metabolically healthy obese phenotypes.¹⁷

PHYSICAL ACTIVITY & DIABETES

Current guidelines by the ADA recommend that all adults with prediabetes and diabetes engage in regular physical activity.^18,19 This recommendation comes from multiple studies showing that exercise, along with other lifestyle changes, can prevent or delay the onset of type 2 diabetes (T2DM) and help manage the illness through weight loss and improved glycemic control (blood glucose level management).²⁰

By reducing intra-abdominal fat that exacerbates insulin resistance, physical activity can delay the onset of and manage T2DM.²¹ Obesity is the strongest risk factor for T2DM, and the ADA recommends the combination of physical activity, diet, and behavioral therapy to achieve a 5% weight loss for overweight or obese individuals with T2DM (a sustained weight loss of >7% is considered optimal).¹⁸ Meta-analyses evaluating the effects of exercise interventions have shown that physical activity can improve glycemic control in T2DM patients even without significant weight loss.^22,23 Moderate-intensity physical activity increases blood flow to skeletal muscles, (increasing delivery), increases muscle glucose uptake capacities (increasing consumption), and increases enzymatic activities related to glucose metabolism (increasing metabolism).²⁴  Furthermore, one meta-analysis found that patient who engaged in aerobic training had significantly reduced HbA1C levels when compared to patients who did not.²² Past studies have reported that a 1% decrease in HbA1C level, even without weight loss, is associated with a 37% decrease in microvascular complications and a 15-20% decrease in major cardiovascular disease events in individuals with T2DM.^25–27

HOW SHOULD I EXERCISE?  

Organizations such as the American Heart Association and the ADA advise that adults engage in at least 150 minutes (or 30 minutes 5 times a week) of moderate-intensity aerobic exercises.^7,18  Additionally, studies suggest that engaging in both aerobic and resistance training may be more effective in managing blood pressure and T2DM than engaging in one type of exercise alone.^7,25,28,29 For improvement in fitness, prevention of weight regain, and increase in weight loss, at least 150 to 300 minutes of moderate physical activity is suggested every week.¹⁶ For those seeking to lose clinically significant amounts of weight long-term, a minimum of 200 to 300 minutes of moderate-vigorous physical activity is recommended every week.

Here are some ways you can get started:^18,19

• Set clear goals: use the SMART approach to set a goal that is specific, measurable, achievable, realistic, and time-bound (eg, “I will take a brisk walk for 20 minutes at 8:00AM before work, 3 times a week, for at least one month”)
• Avoid a sedentary lifestyle: try to avoid sitting for more than 1.5 hours straight and take frequent breaks to walk around
• Start small: start with 10 minutes of exercise you personally enjoy (eg, brisk walks, dancing, bicycling, etc.) and gradually increase the duration
• Incorporate exercise into your daily life: think of ways to be more active in your daily routine (eg, try to take the stairs instead of the elevator, try to walk instead of drive, etc.)
• Track your progress: find a way to track your daily physical activity and progress over time as this can encourage long-term lifestyle changes