From the Guidelines
Moderate-intensity aerobic activities are those that can be conducted whilst having an uninterrupted conversation, such as brisk walking, cycling, or low-impact aerobics, while high-intensity aerobic activities are those where an uninterrupted conversation cannot be maintained, such as jogging, running, or high-impact aerobics. These definitions are based on the most recent evidence from the World Health Organization 2020 guidelines on physical activity and sedentary behaviour 1. The key characteristics of moderate-intensity activities include:
- Ability to have an uninterrupted conversation
- Breathing is harder and heart beats faster, but still able to talk
- Examples include brisk walking (about 5-7 km/h), cycling (8-15 km/h), low-impact or aqua aerobics, yoga gymnastics, weight training, moderate dancing, and recreational swimming The key characteristics of high-intensity activities include:
- Unable to have an uninterrupted conversation
- Heart rate increases substantially and it's difficult to say more than a few words without pausing for breath
- Examples include jogging, running, swimming laps, tennis singles, aerobic dancing, bicycling faster than 16 km/h, and hiking uphill It's essential to note that health guidelines typically recommend at least 150 minutes of moderate-intensity activity per week, or 75 minutes of high-intensity activity, or a combination of both, as stated in the World Health Organization 2020 guidelines 1 and supported by other studies 1. The distinction between these intensity levels is crucial because high-intensity exercise produces similar health benefits in about half the time of moderate-intensity exercise. Your perceived exertion, heart rate, and ability to talk during exercise can help you determine which intensity level you're working at during physical activity. Additionally, the evidence confirms that some physical activity is better than none, and more is better for optimal health outcomes, as stated in the World Health Organization 2020 guidelines 1.
From the Research
Definition of Moderate-Intensity and High-Intensity Aerobic Activity
- Moderate-intensity aerobic activity is defined as an activity in which heart rate and breathing are raised, but it is still possible to speak comfortably 2.
- High-intensity or vigorous-intensity aerobic activity is defined as an activity in which heart rate is higher, breathing is heavier, and conversation is harder 2, 3.
- Examples of moderate-intensity activities include brisk walking, while examples of vigorous-intensity activities include jogging or running 2, 3.
Key Characteristics of Moderate-Intensity and High-Intensity Aerobic Activity
- Moderate-intensity activity approaches the ventilatory threshold 1 (VT1) and lactate threshold 1 (LT1), which reflect boundaries related to individualized disturbance to homeostasis 4.
- Vigorous-intensity activity is between the two thresholds (1 and 2), corresponding with critical power/speed and respiratory compensation point 4.
- The intensity of exercise is the most elusive element of physical activity, but it has important implications for health benefits and cardiovascular outcomes 4.
Recommendations for Moderate-Intensity and High-Intensity Aerobic Activity
- Adults should aim to do at least 150 minutes to 300 minutes a week of moderate-intensity, or 75 minutes to 150 minutes a week of vigorous-intensity aerobic physical activity, or an equivalent combination of moderate- and vigorous-intensity aerobic activity 5, 3.
- Adults should also do muscle-strengthening activities on 2 or more days a week 2, 5, 3, 6.
- Combinations of moderate- and vigorous-intensity activity can be performed to meet the recommendation, and activities can be accumulated toward the minimum by performing bouts each lasting 10 or more minutes 2, 3, 6.