Exercise Intensity and what is it all about

An image exhibiting different exercise intensities

When it comes to exercise, intensity is one of the most important factors in achieving your fitness goals. 

Exercise intensity can be classified into four main levels: 

  • light, 
  • moderate, 
  • vigorous, 
  • maximum. 

Light intensity exercises include activities like walking at a relaxed pace or gentle stretching, where your heart rate increases slightly, but you’re able to carry on a conversation with ease. 

Moderate intensity exercises, such as brisk walking or steady jogging, are a bit more challenging. Your heart rate is noticeably elevated, and while you can still talk, it may be harder to maintain a conversation for long periods. These exercises are great for improving cardiovascular health and endurance.

Vigorous intensity activities, such as running or high-intensity interval training (HIIT), push your body even harder, causing a significant increase in your heart rate and leaving you out of breath. At this level, it becomes difficult to speak more than a few words at a time. Your body sweats more, and you’re working at a level that challenges your stamina and strength. 

Maximum intensity, found in exercises like sprinting or all-out efforts during a circuit workout, takes things to the extreme. You’ll be pushing your body to its limit, unable to speak, and feeling completely out of breath. This level is used to develop speed, power, and peak performance.

To judge your own exercise intensity, there are several methods you can use. The simplest is the talk test, where you monitor how easily you can talk during exercise. If you’re breezing through a conversation, you’re likely working at a light intensity. If speaking is a bit more challenging, you’re probably at a moderate intensity, and if you’re only able to speak a few words, you’re likely at a vigorous or maximum intensity. Another way to gauge intensity is by monitoring your heart rate. 

Two people's shadows stretched along the grey wood of a water-side boardwalk. Lined to the left side with modern units, and on the right an expanse of blue ocean water.
Walking along the beach is a great example of a light-intensity physical activity.

Using a heart rate monitor or manually calculating your maximum heart rate (220 minus your age), allows you to work within specific heart rate zones linked to the intensity’s listed above, hence targeting different goals.

Additionally, the Rate of Perceived Exertion (RPE) scale, which asks you to rate your effort from 1 to 10, is another useful tool to determine how hard you’re working. 

Remember, it is not suitable for everyone to just jump in the deep end and try to work at vigorous or maximal intensities, even in the absence of disease or injury, particularly if the individual has not been consistently active. As we age, we are less ‘resilient’ to loads if untrained, and hence it is important to discuss your goals with your exercise physiologist or other exercise professional to successfully manage training loads. If this is not done appropriately, we tend to see an increase in injuries such as, Achillis tendinopathy, rotator cuff tendinopathy or joint pain such as knee or lower back pain.

A girl plays pickleball in an indoor sports centre.
Casual competitive sports are a fun way to integrate vigorous-intensity physical activity into your schedule.

By understanding these different levels and how to personally assess your intensity, you will be able to manage your training loads as set out by your exercise physiologist or you may have greater success in tailoring your workouts on your own to meet your fitness needs and make more progress.