Obesity and Exercise

Physical activity is one of the OMA's four pillars of clinical obesity treatment, along with nutrition therapy, behavioral modification, and medical interventions. We often talk about obesity and exercise together, since physical activity promotes the body's ability to burn calories efficiently. Inactivity is linked to rising obesity rates and is possibly even more to blame than increased caloric intake.

However, it is important to acknowledge that there are challenges to exercise that individuals with overweight and obesity often experience. There’s much more to the “just move more” advice for weight loss. When you understand these challenges, you can offer more comprehensive advice to patients about obesity and physical activity, including the risks of exercise for obesity. We will explore a few challenges to exercise and potential solutions in this article.

The Relationship Between Exercise and Obesity

Few Americans get the 150 minutes of moderate-intensity activity per week that the CDC recommends. That’s already a challenge for those of us who want to promote good health. But the College of Sports Medicine says that individuals with obesity may need even more than the CDC advisory — up to 250 minutes per week. And it’s not as simple as just saying “walk more.”

The 2018 Physical Activity Guidelines Advisory Committee Report concluded that there is an association between greater amounts of physical activity and attenuated weight gain in adults, and this may be most pronounced when physical activity exposure is at a moderate-to-vigorous intensity and is above 150 per week.

When combined with an energy-restricted diet, the effect of physical activity on body weight and adiposity is additive to diet and enhances weight loss by approximately 20% compared to what is observed with an energy-restricted diet alone. Enhanced long-term weight loss is associated with 200 to 300 min per week or ≥2000 kcal per week of leisure-time physical activity.

The right variety and amount of exercise can both reduce body weight and prevent weight regain. In addition, it may improve:

• Endocrine and immune body responses related to adipose tissue dysfunction, including insulin sensitivity

• Metabolic, musculoskeletal, cardiovascular, pulmonary, mental, sexual, and cognitive health

• Body composition and resting energy expenditure

When we talk about obesity and exercise, we’re also talking about physical activity more generally. This can include non-exercise activity thermogenesis (NEAT)—daily activities like walking, hobbies, and household chores.

Physical activity offers far-reaching benefits. It can improve health both by reducing excess fat as well as the risk for other related metabolic conditions. For example, obesity can contribute to the development and progression of heart disease. Aerobic exercise benefits the heart directly but can also support heart health indirectly by reducing weight and helping keep it off. Obesity increases the risk for insulin resistance, dyslipidemia, chronic inflammation, and endothelial dysfunction, all of which create a favorable environment for someone to develop atherosclerosis and cardiovascular events.

Current Exercise Guidelines

Yes, recommendations for physical activity start at 150 minutes per week. Specifically, a healthy lifestyle should include 150 to 300 minutes of moderate intensity aerobic exercise or 75-100 minutes of vigorous intensity aerobic exercise. Moderate intensity activities would include things like brisk walking, playing volleyball, dancing, or water aerobics. Vigorous intensity activities may include running, a strenuous fitness class, or intense sports like soccer. Some activities, like swimming or cycling, can be adjusted to either moderate or vigorous intensity.

The Best Types of Exercises for Addressing Obesity

For addressing obesity, and for fostering general overall health, a balance of aerobic and anaerobic exercises is best. There is no one perfect form of exercise for weight loss, but the FITT guidelines—which we address in the next section—can help guide specific patients to the right choices for them.

Evidence does not support that any one single mode of physical activity is superior to other modes for the prevention of weight gain or weight loss, provided that the dose of physical activity is sufficient to result in the necessary effects on energy expenditure and energy balance. Moreover, options for non–weight-supported modes should be recommended to accommodate individual needs when body weight or body size limits the ability to engage in weight supported physical activity.

For addressing obesity, and for fostering general overall health, multimodal physical activity, rather than a single mode of physical activity, should be recommended for persons with excess body weight.

Aerobic exercise

Aerobic exercise is any activity that increases the cardiometabolic rate. The exerciser might think of it as anything that causes them to get slightly out of breath. Activities can range from fast walking to swimming, dancing, or sports that entail constant movement. A typical workout might involve a warm-up of some kind with smaller or slower movements, building to the full intensity, then cooling down.

Strength or resistance training

While this anaerobic exercise is not always appreciated for its role in treating obesity, studies show that it can increase resting metabolic rate and reduce metabolic conditions like type 2 diabetes and heart disease. The American College of Sports Medicine recommends at least two sessions of resistance training weekly.

Strength training can help prevent muscle loss during weight loss, while stronger muscles can help protect joints and improve posture.

Balance and flexibility

When starting an exercise routine, some people neglect balance and flexibility. They might think about stretching for a minute or two before an intense workout but not fully include this component of fitness. Optimizing balance can help reduce falls and might even open a person to different forms of exercise that demand balance, like paddle boarding or dance. Benefits of flexibility include reduced risk of injuries, greater range of motion, increased blood flow to muscles, and greater ease in daily activities.

So while balance and flexibility may not impact obesity as directly as other elements of exercise, they can support a productive physical activity regime overall.

HIIT workouts

Some evidence points to the value of high intensity interval training (HIIT) for better weight loss outcomes. With HIIT, a person alternates intervals of near-maximal intensity (around 80-95% of their maximal heart rate) with intervals of lower intensity work as recovery periods (at 40-50% of their maximal heart rate). A HIIT workout might entail strictly cardio-based work (like running, swimming, or biking) or include resistance work (such as free weights, resistance bands, or even body weight work). Some studies support the idea that increased fat oxidation that comes from HIIT workouts leads to increased weight and/or fat loss mass in people with overweight or obesity.

A recent Consensus statement from ACSM however states that HIIT is not superior to other modes of physical activity performed at a moderate-to-vigorous intensity for its effects on body weight and body composition, but HIIT can be an option when not contraindicated and when preferred by the individual.

Light-intensity physical activity is additive to more intense physical activity for effects on body weight regulation and the treatment of excess body weight and adiposity. For individuals for whom moderate- or vigorous-intensity physical activity may not be feasible or is contraindicated, light-intensity physical activity provides a viable alternative to enhance energy expenditure for individuals who choose it over other alternatives. However, to elicit an energy expenditure that is equivalent to moderate-to-vigorous intensity physical activity, light-intensity physical activity will need to be of a longer duration

Medical Evaluations Before Initiating a New Exercise Program

A person with obesity should undergo a medical evaluation before starting an exercise regimen. You will want to examine a patient’s cardio and pulmonary health as well as mobility and range of motion. Different forms of exercise exist for those who run the gamut of fitness, from those who cannot easily stand or walk all the way to those who can move freely.

It’s also important to understand the person’s current level of physical activity. Avoid making assumptions that someone is inactive simply because they are obese. You could conduct an assessment such as the PAR-Q, designed for people ages 15-69, or the PAR-Q+ for people of any age.

You may also consider the potential need to adjust medications, particularly diabetes or blood pressure medications.

Exercise Prescriptions and Tracking Progress

Your guidance can go a long way to helping patients with obesity and exercise. Some literature reviews show that people adhere better to an exercise regime when their doctor prescribes it. They may simply not know where to start, or they may benefit from knowing they have support.

When building an exercise program, we consider four main things: frequency, intensity, time, and type, or FITT. These four factors should complement each other to arrive at a regimen that meets recommendations and the exerciser's needs. Frequency and intensity are particularly important when it comes to weight loss.

You may also encounter the acronym FITTE, which adds “enjoyment,” another important factor. People will be more likely to stick to an exercise activity if they enjoy it. Another term is FITT-VP, which includes volume and progression. You may find that one way of framing the plan works better for you and your patients than another.

Here is an example of what an exercise prescription might look like:

• Frequency: Five days a week

• Intensity: Moderate

• Time: 30 minutes a day

• Type: Walking at a pace where you can talk but not sing

• Volume: Distance walked (keep track to gauge progress)

• Progression:
  • Start at 10 minutes a day and increase by five minutes each month
  • Increase the distance as time increases

See our Obesity Algorithm for additional information on exercise prescriptions.

Tracking exercise can be both motivating for the patient and informative for their doctor. There are many ways they can track their activity, such as:

• Daily activity logs (written or electronic)​

• Pedometer/accelerometer logs​

• Dynamic training metrics (e.g., miles run, laps swum, etc.)

• Resistance training metrics (e.g., muscle-circumference measurements, reps, sets, etc.)

• Body fat percentage measurements

Challenges Related to Exercise and Obesity

Any productive conversation with a patient about obesity and exercise begins with empathy. By understanding possible barriers and concerns, you can help guide people to an exercise plan that works for them. Motivational interviewing is one technique that can help you understand the patient’s motivations and start them off on the right foot (pun intended).

These are some of the common challenges you might hear from patients.

I find exercise difficult and uncomfortable

One reason to use the term physical activity is that exercise carries a negative connotation of arduous and unenjoyable labor. This perception creates a mental barrier for many people. Physical activity can include traditional exercise as well as NEAT. A patient may find it palatable to take simple actions like parking farther from the store, taking the stairs instead of the elevator, or breaking up an hour-long walk into 10-minute increments over the day.

Walking is a particularly useful entry point into moving more. The adult recommendation can be easily obtained by walking one hour a day. Many find walking easy, safe, and enjoyable. Effective for both the weight loss and maintenance stages of weight management, it can help improve cardiovascular fitness, and is consistently shown to improve mortality. However, walking itself (or exercise in general) is not a great weight loss tool. Exercise tends to actually reduce, not increase metabolism, plus it can make one more hungry, which leads to increased intake. Therefore, it’s important to encourage a person with obesity to find other forms of activity they enjoy as well.

Some people like to dance, swim, bike, or play a sport just for the fun of it. When they pursue an activity for its own sake rather than as a chore on their “to do” list, they may find it easier to stick with it.

I feel self-conscious when I exercise

Many people, of all body types, report feelings of self-consciousness when they exercise. Add to that the stigma and self-esteem challenges of obesity, and people may wish to avoid exercise entirely. Encourage them to find what works for them, whether it means working out in a home gym, walking with a supportive friend, or even seeing a therapist to work on their self-image. They may also find that, when they truly enjoy an activity, they forget about mental distractions. The important thing is not to judge their feelings when helping them adopt an exercise regimen.

Physical activity makes me hungrier

As the body expends energy through physical activity, systems work to defend the set point (the body’s programmed weight locked within the hypothalamus). As more calories are burned, the body will compensate for the loss in fat by increasing hunger signals and reducing satiety. This may lead to overeating, larger portions, and consumption of comfort foods. The end result is replacing calories lost from physical activity. To combat this physiological routine, encourage a patient to eat properly and not “over-diet.” Cutting calories too low can cause the loss of key nutrients.

Anyone increasing physical activity should start with a well-balanced and proper diet. They need adequate protein and healthy fats to reduce food cravings and help with satiety. In addition, they can learn when the feelings or thoughts of hunger and craving are legitimate. “Head hunger” is more related to a psychological hunger than a true physical hunger and is natural when making dietary changes. Cravings are sometimes related moreso to habits than true physiological need for a nutrient or food.

I’m afraid of getting injured

Depending on the extent of excess weight and the types of physical activity, individuals with overweight and obesity can be more prone to workout injuries. Increased torque on weight-bearing joints, especially the knees and ankles, can increase the risk of injuries. It is important to avoid injuries that can lead to diminished mobility, as this will not only reduce confidence in physical activity but also increase the risk of additional weight gain. Stretching, slow progression, working with certified physical instructors experienced in bariatrics, and patience are key. Proper nutrition, rest, and listening to the body to differentiate muscle growth from dangerous muscle pain are also key to avoiding injuries from physical activity.

For individuals with 100 or more pounds of excess weight, consider starting with chair exercises, water aerobics, and bike riding. These activities are safer, gentler on the joints, and still effective for cardiovascular fitness and weight reduction.

It’s too hard to stick with exercise

Consistency can be a challenge with exercise. However, consistent exercise serves as a great buffer in weight maintenance because caloric intake, stress, sleep patterns, food intake, and metabolism vary considerably. As caloric intake and other metabolic factors fluctuate, physical activity serves as a method for energy expenditure to offset factors that impede weight loss. Ways to increase consistency with physical activity include: finding an activity that is enjoyable, creating accountability (can be in the form of fitness trackers, calendars, and accountability partners), and group fitness.

Exercise is often suggested as a solution to weight loss as if it were effortless. However, several challenges create boundaries for engaging in physical activity. Finding strategies to overcome barriers to physical activity is essential to obtaining physical fitness goals and ensuring not only proper weight loss but, most importantly, weight maintenance.

Obesity and exercise in perspective

Keep in mind that exercise is only one of the four pillars and different individuals may benefit from different combinations of the pillars. Exercise, however, is almost universally beneficial. Obesity is a disease and individuals who need to lose weight to eliminate chronic medical conditions or prevent disease ultimately have to make the choice and the commitment to follow an exercise program to lose weight.

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