METs (Metabolic Equivalents): Understanding Daily Targets, Benefits, and Calculating Your Activity

How Many METs Per Day Is Good?

While there isn't a single "good" number for daily METs, health organizations generally recommend aiming for 500-1000 MET-minutes of moderate-to-vigorous physical activity per week for substantial health benefits, which averages out to approximately 70-140 MET-minutes per day.

What Are METs?

MET stands for Metabolic Equivalent of Task. It is a physiological measure expressing the energy cost of physical activities and is used to standardize the intensity of different forms of exercise. One MET is defined as the energy expended while sitting quietly, which is roughly equivalent to consuming 3.5 milliliters of oxygen per kilogram of body weight per minute (3.5 mL/kg/min).

• 1 MET: The energy expenditure of resting.
• 2 METs: An activity requiring twice the energy of resting.
• 6 METs: An activity requiring six times the energy of resting.

This standardized unit allows us to compare the intensity of various activities regardless of an individual's body weight or fitness level, providing a universal metric for understanding exercise demands.

Why Are METs Important?

Understanding METs is crucial for several reasons:

• Quantifying Exercise Intensity: METs provide an objective way to describe how hard your body is working during an activity.
• Setting Health Guidelines: Major health organizations use METs to define recommended levels of physical activity for disease prevention and health promotion.
• Personalized Training: For fitness professionals, METs can help in designing appropriate exercise programs by ensuring clients are working within safe and effective intensity zones.
• Tracking Progress: By monitoring the MET values of your activities, you can better track your overall physical activity volume and progression.
• Health Risk Assessment: Studies link specific MET-minute targets to reduced risks of cardiovascular disease, type 2 diabetes, certain cancers, and improved mental health.

Understanding MET-Minutes

While METs describe intensity, MET-minutes quantify the total volume of physical activity. It's calculated by multiplying the MET value of an activity by the duration (in minutes) you perform it.

Formula: MET-minutes = METs x Duration (minutes)

For example:

• Brisk walking (4 METs) for 30 minutes = 4 x 30 = 120 MET-minutes.
• Running (8 METs) for 15 minutes = 8 x 15 = 120 MET-minutes.

This metric allows for a comprehensive measure of your total weekly or daily physical activity, encompassing both intensity and duration.

Current Physical Activity Guidelines

Leading health organizations, such as the World Health Organization (WHO), the Centers for Disease Control and Prevention (CDC), and the American College of Sports Medicine (ACSM), provide guidelines often expressed in terms of MET-minutes.

The general recommendation for adults is to accumulate at least:

• 150 to 300 minutes of moderate-intensity aerobic activity per week, or
• 75 to 150 minutes of vigorous-intensity aerobic activity per week, or
• An equivalent combination of both.

Let's translate this into MET-minutes:

• Moderate-intensity activities typically fall between 3.0 and 5.9 METs (e.g., brisk walking, leisurely cycling, dancing).
  • 150 minutes x 3 METs = 450 MET-minutes
  • 300 minutes x 5.9 METs = 1770 MET-minutes
• Vigorous-intensity activities are typically 6.0 METs or higher (e.g., running, swimming laps, high-impact aerobics).
  • 75 minutes x 6 METs = 450 MET-minutes
  • 150 minutes x 8 METs (e.g.) = 1200 MET-minutes

Therefore, the general target for substantial health benefits is approximately 500-1000 MET-minutes per week. This range provides a robust protective effect against chronic diseases and premature mortality.

Dividing this weekly target by seven days, we get an average daily goal:

• 500 MET-minutes / 7 days ≈ 71 MET-minutes per day
• 1000 MET-minutes / 7 days ≈ 143 MET-minutes per day

In addition to aerobic activity, guidelines also recommend:

• Muscle-strengthening activities involving all major muscle groups on 2 or more days a week. While these are critical, their MET values are less standardized and often harder to quantify precisely in daily totals.

Calculating Your Daily METs

To estimate your daily MET-minutes, consider the duration and intensity of your activities. Here are some common activities with approximate MET values:

• Light Intensity (1.0-2.9 METs):
  • Standing: 1.5 METs
  • Slow walking (e.g., strolling): 2.0 METs
  • Light housework: 2.5 METs
• Moderate Intensity (3.0-5.9 METs):
  • Brisk walking (3-4 mph): 3.5-4.5 METs
  • Leisurely cycling (<10 mph): 4.0 METs
  • Dancing: 4.5 METs
  • Swimming (leisurely): 5.0 METs
  • Gardening: 4.0 METs
• Vigorous Intensity (6.0+ METs):
  • Running (6 mph / 10 min/mile): 9.8 METs
  • Swimming (laps, moderate to vigorous): 8.0-10.0 METs
  • High-impact aerobics: 7.0 METs
  • Competitive sports (e.g., basketball, soccer): 8.0 METs

Example Daily Accumulation:

• 30 minutes of brisk walking (4 METs) = 120 MET-minutes
• 15 minutes of gardening (4 METs) = 60 MET-minutes
• 20 minutes of light housework (2.5 METs) = 50 MET-minutes
• Total for the day: 120 + 60 + 50 = 230 MET-minutes

This example significantly exceeds the average daily target, demonstrating how easily MET-minutes can accumulate throughout the day.

Factors Influencing Your METs Goal

The "good" number of METs for you can vary based on several personal factors:

• Current Fitness Level: Beginners should start gradually and build up their MET-minutes over time. Trying to hit high targets too quickly can lead to injury or burnout.
• Health Conditions: Individuals with chronic diseases (e.g., heart disease, diabetes) or specific injuries may need modified activity plans. Always consult a healthcare professional.
• Age: While the general guidelines apply to adults across a wide age range, individual capacity and recovery times can vary.
• Specific Goals: If your goal is weight loss, performance enhancement, or training for an event, you may aim for higher MET-minute totals.
• Time Availability: It's more effective to consistently hit a realistic target than to aim for an unsustainable high one.

Practical Strategies to Increase Your Daily METs

Increasing your daily MET-minutes doesn't always require dedicated gym time. Integrating more activity into your daily life can be highly effective:

• Embrace Non-Exercise Activity Thermogenesis (NEAT):
  • Take the stairs instead of the elevator.
  • Park further away from your destination.
  • Walk or cycle for short errands.
  • Stand and move during phone calls or while working.
• Schedule Dedicated Exercise:
  • Plan moderate-intensity walks, jogs, or cycling sessions.
  • Incorporate strength training, which, while harder to quantify in METs, is vital for overall health.
  • Try group fitness classes like dance, aerobics, or martial arts.
• Break Up Sedentary Time:
  • Set reminders to stand up and move for 5-10 minutes every hour.
  • Perform short bursts of activity (e.g., bodyweight squats, jumping jacks) throughout the day.
• Choose Active Hobbies:
  • Gardening, hiking, recreational sports, or active playtime with children or pets can significantly contribute to your MET-minute total.
• Progressive Overload:
  • Gradually increase the duration, frequency, or intensity of your activities to continue challenging your body and accumulating more MET-minutes.

The Bottom Line

While there isn't a precise "good" number of METs per day, the scientific consensus points to accumulating 500-1000 MET-minutes per week from moderate-to-vigorous physical activity for optimal health benefits. This averages out to roughly 70-140 MET-minutes per day.

Focus on consistency and incorporating a variety of activities that you enjoy. Listen to your body, progress gradually, and if you have any underlying health conditions, consult with a healthcare professional or an exercise physiologist to tailor a physical activity plan that is safe and effective for you. Every minute of activity counts towards a healthier you.