By Natasha Vani, MSc., ATCP

Daily physical activity has many benefits, many of which are becoming well known: improved quality of sleep; better self-esteem; reduced risk of various cancers, heart disease and diabetes are just a few of the benefits. Depression and feelings of anxiety may also decrease, body weight may be controlled and energy levels may increase.

Despite our knowledge of the numerous benefits of exercise, the exact exercise prescription is often misunderstood or simply neglected. In order to achieve the health benefits associated with exercise, we need to know how long our activity should last, how often we need to be active and how hard we need to push ourselves.

The FITT principle
The most common method of assessing or recording your daily activity is through the FITT principle. This acronym represents the four most important aspects of tracking your exercise and provides a means to compare yourself to the recommended guidelines.

• Frequency represents the number of activity sessions per week.
• Intensity refers to how hard you exert yourself and is most accurately measured by a percentage of your maximum heart rate (MHR).
• Time is simply an indication of how long each session lasts and is usually expressed in minutes.
• Type is the mode of activity: swimming, running, walking, etc.

The current guidelines
According to the American College of Sports Medicine, your exercise prescription should be as follows:

Frequency: Preferably, all days of the week

Intensity: Moderate

Time: 30 minutes or more (aiming for 60 minutes)

Type: Any type of activity that works the large muscle groups of the body. Brisk walking, jogging, cycling, swimming and dancing are all great examples.

Are you working hard enough?
Of these four factors, intensity is usually the most misunderstood. The common question is what is moderate intensity? Intensity is most commonly and most accurately gauged by heart rate. Moderate intensity usually translates to between 50 and 75% of your maximum heart rate (max heart rate is simply the highest number of beats your heart can reach each minute).

How do you calculate max heart rate?
Max heart rate is estimated by the equation 220 minus your age.

If you are 20 years old, your estimated maximum heart rate is roughly 220–20 = 200.

 To calculate 50 to 75% of this maximum heart rate simply multiply 200 by 0.5 and then by 0.75:

50% of your max heart rate: 0.5 x 200 = 100
75% of your max heart rate: 0.75 x 200 = 150

Therefore, if you are a 20-year-old male or female, you should aim to get your heart pumping at anywhere from 100 to 150 beats per minute. To find your heart rate, simply count the number of beats in a 15-second period and multiply that number by four.

Working at an optimal intensity level is one of the key factors to receiving health benefits from exercise. If you work closer to 75% of your max heart rate, 30 minutes a day is sufficient. If this is too difficult, work toward the lower end of the scale but aim for 60 minutes of activity instead of 30 minutes. A quick check of your heart rate half way through a walk is the best way to determine whether or not you need to pick up the pace.

Along with daily exercise, a solid nutrition and vitamin regime are vitally important to health. View our nutritional guidelines and our vitamin and supplement plans to ensure your efforts are being translated to health gains.