How Much Exercise Do You Need in a Day?

How much physical activity do you need in a day?

When people answer this, they’re often working with old information, urban legends, and “facts” invented by marketing companies to sell products. Let’s lay out some facts for you.

Back in 1995, the Centers for Disease Control (CDC) and the American College of Sports Medicine issued a generic recommendation that “Every US adult should accumulate 30 minutes or more of moderate-intensity physical activity on most–preferably all–days of the week.” The goal was to encourage people to become more active in order to promote health, reduce the risk of chronic disease, and prevent premature death. Unfortunately, that “accumulate 30 minutes” and “moderate-intensity” bits were confusing and pretty much ignored.

More recently, the American Heart Association and the American College of Sports Medicine have just recently released their updated guidelines for “Physical Activity and Public Health.” These new recommendations are based on current scientific research from an expert panel of physicians, epidemiologists, exercise scientists, and public health experts. The goal of the panel was to create guidelines that would promote health and fitness and prevent disease.

1. Healthy Adult (18 to 65 years old)
Aerobic Exercise

At least five days a week of moderate intensity, or at least three days a week of vigorous intensity exercise.

Moderate Intensity

• 30 minutes, or multiple 10-minute bouts
• A “bout” must last 10 minutes or longer to count
• Walking to the trash can does not count unless it takes 10 minutes of exertion.)

Vigorous Intensity

• 20 minutes, and it should not be broken up
• Running up one or two flights of steps doesn’t count toward the 20 minutes

Muscle Strengthening

• At least 2 days a week
• The days should be nonconsecutive
• A “day” of muscle strengthening should include eight to ten exercises involving the major muscle groups
• Each exercise should be done with a weight that will cause fatigue at 8 to 12 repetitions
• Most fitness experts recommend 2 to 3 sets of 8 to 12 repetitions for each exercise for muscle strengthening
• Muscle strengthening activities include weight training program, weight bearing calisthenics, and stair climbing

2. Older Adults (>65 years old) or
Adults (50 to 64) with chronic conditions or physical limitations
Aerobic Exercise

Moderate Intensity
Moderate intensity activity in this group is defined as a 5 or 6 level of effort on a 10-point scale where zero is sitting and 10 is “all-out” effort. It should include at least five days a week of moderate intensity, or at least three days a week of vigorous intensity exercise.

• 30 minutes, or multiple 10-minute bouts
• Activity should produce a noticeable increase in heart rate and breathing frequency
• Activity can be cumulative for the day as long as each episode of moderate activity is at least 10 minutes

Vigorous Intensity
Vigorous activity in this group is a 7 or 8 on the same 10-point scale.

• 20 minutes, and it should not be broken up
• Activity is not cumulative for the day
• Activity should cause large increases in heart rate and breathing frequency.

Muscle Strengthening

• At least 2 days a week
• The days should be nonconsecutive
• Each day, 8 to 10 exercises focusing on the major muscle groups should be performed
• The appropriate weight for the exercise will yield ten to fifteen repetitions before fatigue
• The level of effort for muscle strengthening should be moderate to high, or 5 to 8 on a 10-point scale where 0 is no movement and 10 is maximal effort of the muscle group
• Muscle strengthening activities include weight training program, weight bearing calisthenics, and stair climbing

Flexibility Activity and Balance Exercises

• At least 2 days a week for ten minutes each day
• Balance activities are recommended for individuals at risk for falls
• Stretching should focus on the major muscle groups
• Stretching should last 10 to 30 seconds for each static stretch and 3 to 4 repetitions for each stretch
• Ideally, flexibility activities and stretching would be performed before each episode of exercise, whether it is aerobic or strengthening

Vigorous Vs. Moderate Aerobic Training

Moderate intensity is defined as 3.0 to 6.0 METS (Metabolic equivalents), which is equivalent to a brisk walk (2.5 to 4 miles per hour) that perceptibly increases the heart rate. One MET is defined as the energy or oxygen used by the body to sit quietly. (For example, sleeping is around 0.9 METS and running a 7-minute mile is around 14 METS.) Three METS would be 3 times the energy of sitting quietly. Typically, you could still have a conversation during a moderate intensity exercise.

Vigorous intensity is defined as above 6.0 METS, which is equivalent to jogging or an activity that causes rapid breathing and a substantial increase in heart rate. Typically, vigorous activity does not include walking unless you are walking very fast (greater than 4 mph). Conversation should be difficult during vigorous activity.

Physical Activity and Health – Final Thoughts

It should be no surprise that if you exceed the recommendations listed here, you can further reduce your risk of inactivity-related chronic disease and realize additional health benefits and physical fitness.

That said, if you’re not currently active, start exercising one day a week and increase one day each week until you reach your goal. If 30 minutes is too much, start with ten minutes and work your way up. Be patient and realize that fitness is a process.

These are recommendations — NOT immediate expectations. Do not use this information to beat yourself up! Set small attainable goals, and you’ll soon find success.

[Editor’s Note: These guidelines are designed for the “public” health. Your individual health needs to be considered by you and your doctor before starting any exercise regimen, so consult your physician first.]

Sources
NCBI