Intensity Vs. Duration in Exercise

Regular exercise contributes to your good health by helping you maintain your weight, and reduces your risk of heart disease, type 2 diabetes and other illnesses. The intensity and duration of your workouts affect the degree of these potential health benefits. While intensity and duration may seem to describe similar components of exercise, intensity reflects the quality of effort that you put into your workout while duration deals directly with the quantity of exercise that you complete.

  1. Recommendations

    • The Centers for Disease Control and Prevention recommends 150 minutes of moderate-intensity exercise weekly or 75 minutes of vigorous-intensity exercise for healthy adults. Activities such as walking and swimming are considered moderate forms of exercise, whereas running and cycling at a challenging pace are considered vigorous forms of exercise. The recommendations may seem daunting, but you can perform 30- to 45-minute sessions at moderate intensity four to five days a week to reach this goal. If you're short on time, increase the intensity of your exercise to meet the vigorous-intensity recommendation.

    Intensity

    • One method for determining the intensity of your workout assesses your ability to carry on a conversation or sing a song. During moderate-intensity exercise, you should be able to hold a simple conversation but have trouble singing. Vigorous intensity is characterized by the inability to speak more than a few words without having to pause for air. Another method uses your maximum heart rate, with moderate intensity taking place at 50 to 70 percent of your maximum and vigorous intensity bumping it up to 70 to 85 percent. To determine your personal ranges, multiply your maximum heart rate by the low-range percentage (i.e. 0.70) and then repeat for the high-range percentage (i.e. 0.85). The result approximates your target heart rate during the corresponding intensities.

    Benefits

    • You can achieve similar health benefits in less time if you work out at a higher intensity, as illustrated by the CDC guidelines. For example, an individual who completes 20 minutes of vigorous-intensity training on a treadmill gains the same or greater benefits than an individual walking at a slow pace for an hour. While the person walking at a slow pace completed 40 additional minutes of activity, the person exercising at a vigorous intensity challenged her cardiovascular system more.

    Achieving Balance

    • Set realistic exercise goals. Completing 30 consecutive minutes of exercise may be difficult if you've been inactive for a while. Start with three sessions of 10 minutes each of light exercise during a day. Gradually increase the time until you can exercise for 30 minutes, then gradually increase your intensity. Don't jump headfirst into exercising at an intensity beyond your current fitness level because you could easily injure yourself. Check with your medical provider before beginning a new exercise routine if you have any concerns or have been inactive for a while.