Page 6 - Physical Activity

Energy Balance

The key to losing weight is in the concept of energy balance. Taking in the same numbers of calories each day that you expend through your daily activities will place you in energy balance. Consuming a greater number of calories than you expend results in weight gain, but expending more calories than you consume results in weight loss.

A combination of diet modifications and a physically active lifestyle is the best way to get your body out of energy balance! An energy imbalance of 250-500 calories per day will result in a weight loss of ½ - 1 pound per week. In order to lose weight healthfully and maintain that loss in the long term, you should strive to lose 1/2-2 pounds per week.

Physical activity vs. exercise

Leading a physically active lifestyle doesn’t just mean going to the gym on a regular basis. It is also about getting more physical activity minutes in our typical daily routine. This is called Lifestyle Physical Activity, and includes things such as walking to class, or taking the stairs rather than the elevator. All of those small increments of activity throughout the day add up to a lot of minutes. Those minutes add up to expended calories, putting you well on your way to energy imbalance, which will help you lose weight.

Lifestyle Physical Activity: 10,000 steps

The most common form of Lifestyle Physical Activity is walking. It’s easy, it’s free, and can be a fantastic workout. You can also get friends involved in walking with you to help keep you motivated. How much walking is enough physical activity? Strive to accumulate 10,000 steps each day. 10,000 steps are equal to about 5 miles. You can keep track of your steps with a pedometer. Consult the resource list at the end of this program to find pedometers.

Step Equivalents per Minute of Activity:

Weight lifting, (moderate effort) - 121, (vigorous effort) - 182
Swimming laps - (leisurely) - 182, (moderate) - 212, (vigorous) - 303 
Tennis - 212 
Volleyball - 121
Yoga - 76
Stairmaster - 273 
Stationary bicycling (moderate effort) - 212, (vigorous effort) - 318 
Step aerobics - 273
Walking 3 mph - 100 
Walking slow - under 2 mph - 61 
Walking 3.5 miles per hour - 115 
Walking 4 miles per hour - 152 
Walking 5 miles per hour - 242
Basketball - shooting baskets - 136 
Basketball game - 242 
Bicycling - 242 
House cleaning - 91
Jump rope - 303

Exercise and Weight Loss

Exercise is a subset of physical activity that is more structured and planned. There are 2 types of exercise that people most often think about: aerobic, or cardiovascular exercise, and resistance exercise, or weight training. The best exercise plan includes a balance of both types of exercise. We’ll discuss each one individually. 

With regard to aerobic exercise, there are 4 principles involved in creating your fitness plan: Frequency, Mode, Duration, and Intensity. Refer to: Exercise Guidelines for Physical Fitness.

Frequency

This simply refers to how often you exercise or are physically active. The American College of Sports Medicine has stated that everyone should engage in some type of physical activity at least five days per week. If weight loss is your goal, you should strive to get some type of physical activity every day. Specifically, you should aim for 3-4 aerobic workouts per week.

Mode

This refers to the type of physical activity you choose. There are no rules here, anything you can do to get your heart rate up and your body moving is great. The most important thing here is to choose something enjoyable! Running, cycling, tennis, walking, fitness classes, swimming, rollerblading, or a game of ultimate Frisbee with friends are all great options.

Duration

The American College of Sports Medicine (ACSM) has stated that:

• 45-60 minutes of moderate intensity exercise per day are necessary for weight loss. You can break those 45-60 minutes up into smaller sessions throughout the day and fit them in wherever you can.

• You should try to get at least 20 continuous minutes of activity, both for cardiovascular endurance and for burning fat as your fuel. Start with 3 20-minute bouts of exercise each day and work up to longer sessions as you become fitter.

You should try to get at least 20 continuous minutes of activity, both for cardiovascular endurance and for burning fat as your fuel. Start with 3 20-minute bouts of exercise each day and work up to longer sessions as you become fitter.

Intensity

The intensity of your exercise session is simply how hard you are working. The ACSM states that a moderate intensity is necessary to start seeing benefits. The best way to determine the intensity of your workout is by using your heart rate. The target heart rate range for moderate intensity is defined as 60-80% of your maximal heart rate, which you can calculate using the following formula:

Max HR = 220-Age 
60% max =Max HR x 0.6 beats per minute
80% max =Max HR x 0.8 beats per minute

For example, if you are 20 years old:
Max HR = 220-20 = 200 beats per minute 
60% max = 200 x 0.6 =120
80% max =200 x 0.8 = 160

Thus, a 20 year old individual’s heart rate range is between 120 and 160 beats per minute. Remember, this is just an approximation. While you should be working at least at 60%, it’s healthy to work above that level as well. The heart is a muscle and needs to be trained at a variety of different intensities, just like every other muscle in the body. Thus, you should vary the intensity of your workouts to maximize the cardiovascular benefit. If you can maintain an exercise intensity of 150 beats per minute for your 45-60 minute workout, do it.

Monitoring your heart rate is easy. You should use the pulse found in the neck or in the wrist. To find your pulse, place your index and middle fingers about 1 inch away from the Adam’s apple, on either side of the neck. Do not use you’re your thumb! Once you find your pulse, simply count the number of beats in 30 seconds and multiply that number by 2 to get your heart rate in beats per minute.  

In addition to monitoring your heart rate, another way to measure the intensity of a workout is to use the Rating of Perceived Exertion Scale (RPE). This subjective measurement is used to answer the question, “How hard does it feel like I’m working”. Your response on the scale will let you know if you are working in your target heart rate range. For more information and to view the scale, refer to: Exercise Guidelines for Physical Fitness.

Resistance Training for Weight Loss

Ultimately the goal of losing weight is to decrease the amount of fat mass in the body. However, the body doesn’t distinguish between the kinds of pounds you’re losing. People lose muscle mass as well as fat mass. Muscle mass is extremely important in a weight loss program because it is the only metabolically active tissue in the human body. It’s the only tissue that burns a significant amount of calories each day. It has a major influence on resting metabolic rate. Thus, the more muscle mass you have, the more calories you expend simply sitting still.

Resting metabolic rate

Resting metabolic rate is the minimum number of calories a person needs to survive. Think of it as the number of calories you would burn if you sat still and did nothing for 24 hours. The more muscle mass you have, the higher your resting metabolic rate will be.

Weight loss decreases your resting metabolic rate. As there is less mass to be supported when doing daily activities, the energy requirement for that activity drops. For example, a 150 pound person may expend 10 calories to climb two flights of stairs, while a 120 pound person may only expend 6 climbing those same flights if stairs.  Resistance training will help maintain the muscle mass you want, and keep your metabolism moving!

Resistance training is also great for increasing “muscle tone,” or addressing some of the physique concerns you may have. The more you strengthen a particular muscle group, the more muscle tone you’ll have. However, remember that muscle definition results from increasing the size of the muscle AND decreasing the amount of fat covering it up. Because we can’t choose where our body takes fat from, it is virtually impossible to tone ONLY one body part.

Resistance Training Programs

Resistance training helps the body build new muscle tissue. It does this by placing more demand on the muscle than it is used to, creating micro-tears in the tissue. The body then builds new tissue to repair the tears, resulting in increased muscle mass. This is called muscle overload, which you can read more about here. Refer to: Designing a Resistance Training Program.  A resistance-training program has 2 objectives: increasing muscle strength, and increasing muscle endurance.

Muscle strength refers to the ability to lift a heavy load a small number of times while muscle endurance is the ability to meet a muscle demand over a long period of time. For example, lifting a heavy box from the ground requires more muscle strength, while climbing ten flights of stairs to the top of the Psychology Building requires more muscular endurance.

A resistance-training program should work on both of these. It should also be a total body workout, meaning that all the major muscle groups should be worked on. There are 8 major muscle groups in the body: Chest, back, biceps, triceps, shoulder, abdominals, quadriceps and hamstrings. There are also a few more minor muscles such as calves, gluteals, or thigh muscles that can also be included in your program
For information on how to design a resistance training program refer to: Designing a Resistance Training Program.

If you are at all unsure of how to use a piece of equipment or how to correctly perform an exercise, ask someone at your fitness facility to demonstrate it for you.

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