An easier way to gauge cardiovascular fitness

Defining Fitness 

We often use the term fit to describe someone who looks healthy and trim with muscular definition. But the more technical definition refers to cardiovascular fitness. The level of cardiovascular fitness is determined by how efficiently the heart, lungs, blood vessels and red blood cells supply muscles with oxygen during sustained exercise, along with the ability of the muscles to use that oxygen. It is also known as cardio respiratory fitness or aerobic fitness.

Using METs To Gauge Fitness

An easier way to gauge cardiovascular fitness is to measure it in metabolic equivalents (METs). One MET is the amount of oxygen used when you are completely inactive, such as sitting still or sleeping. Average healthy but non-athletic middle-aged men and women have peak exercise capacities in the range of 8 to 10 METs; marathon runners can have values as high as 18 to 24.

The easiest way to find out where you currently stand is to go to a gym and ask to get on an exercise machine that displays your MET level. Many models of treadmills, elliptical trainers and rowing machines have built in MET calculators. If an exercise machine with a MET display is not available, you can estimate your exercise intensity level in METs according to the type of physical activities you do. For example, walking at 3 miles per hour puts your level at about 3.5 METs. Jogging at a pace of 5 miles per hour (12-minute miles) brings the intensity level to 8 METs. Listing different physical activities and their associated intensity levels are readily available.

What Is the Right Amount of METs for Me?

Similar to maximum heart rates adjusted for age, exercise researchers have developed a simple to use calculation to find out your target MET level:

• For women, MET level = 14.7 - (0.13 x your age in years)
• For men, MET level = 14.7 - (0.11 x your age in years)

For example, a 45-year-old woman has a target MET level of almost 9 METS.

Hitting your target METs or higher indicates very good to excellent cardiovascular fitness. Falling under 100% is associated with diminished health status. Thirty minutes of dedicated exercise at moderate intensity most days of the week is likely to achieve your target  MET level. Doing higher-intensity workouts on fewer days also works, but people stick with this one less often. To know for sure that you are hitting your target, measure your METs now and track your progress during the coming weeks.