Physical activity is classified into different levels to help people manage their health and fitness goals. These classifications, such as “very active,” are based on standardized measurements of effort and energy expenditure. Understanding these official metrics provides a clear, health-based target for individuals aiming to maximize the benefits of exercise. Defining what constitutes a high level of activity allows for consistent guidance from public health organizations.
Understanding Intensity Scales
The scientific community primarily uses the Metabolic Equivalent of Task (MET) to quantify activity intensity. One MET represents the amount of energy a person expends while sitting quietly at rest, which serves as a baseline for all physical activity. Activities are classified by how many times greater their energy expenditure is compared to this resting rate. Vigorous-intensity activities are defined as those requiring 6.0 METs or more.
The Rate of Perceived Exertion (RPE) scale is another tool used to gauge intensity, relying on an individual’s subjective feeling of effort. This scale, often ranging from 6 (no exertion) to 20 (maximal exertion), helps people monitor their workout intensity without specialized equipment. For a vigorous activity, a person would typically rate their effort at a 7 or 8 on a modified 1-to-10 scale, reflecting heavy breathing and a substantial increase in heart rate.
The Official Threshold for Very Active
The official definition of “very active” is based on the total volume of vigorous-intensity aerobic physical activity accumulated per week. Major health organizations provide specific weekly recommendations, encouraging adults to achieve a minimum of 75 to 150 minutes of vigorous-intensity aerobic activity each week.
The “very active” classification generally refers to individuals who significantly exceed these minimum recommendations for health benefits. A high total volume of activity is often quantified in MET-minutes, a calculation that multiplies the MET value of an activity by the time spent doing it. Being considered “very active” typically means accumulating well over the equivalent of 500 to 1,000 MET-minutes per week, which indicates a pattern of sustained, high-level exertion.
Differentiating Vigorous and Moderate Activity
Vigorous activity is clearly distinguished from moderate activity by the difference in physiological effort and energy expenditure. Moderate-intensity activities fall into the range of 3.0 to 5.9 METs, while vigorous activities begin at 6.0 METs or higher. For example, a brisk walk typically falls in the moderate range, but a competitive race walk or a run is firmly in the vigorous category.
A practical method for distinguishing between the two levels is the “Talk Test,” which relies on breathing effort. During a moderate activity, a person can generally talk but cannot sing comfortably. In contrast, a person engaged in a vigorous activity will only be able to say a few words at a time before needing to pause and catch their breath.
Examples of Vigorous Physical Activity
Many common exercises qualify as vigorous, provided they are performed with the necessary level of intensity. Running or jogging, for instance, is a definitive example of an activity that requires 6.0 METs or more, especially when sustained for a period of time. Swimming laps consistently and at a fast pace also meets the criteria for vigorous intensity, as does cycling at a speed of 10 miles per hour or faster.
Certain sports and fitness classes are inherently vigorous due to their demands on the cardiovascular system. Activities that involve rapid movements and significant physical exertion include:
- Playing singles tennis, competitive soccer, or basketball.
- Jumping rope.
- Heavy yard work involving continuous digging.
- Hiking uphill with a backpack.
The key to reaching the “very active” threshold is maintaining the high effort level for an extended duration.