Cardio 101: What It Is, Why You Need It, How Much to Do

By Natalie Lawson | February 23, 2016 | Rally Health

Couple running bridge

Why you should exercise

Exercise is probably the single best thing you can do for your health. Experts even go so far as calling it close to a “magic bullet” – that’s strong stuff.

When people talk about “exercise” they usually mean cardio, or aerobic, exercise. This type of exercise works your large muscles over and over (think running) and pushes your heart and lungs to work hard. Over time, this makes your heart stronger — it’s a muscle, after all — and more efficient. This can lower your resting heart rate and help lower your blood pressure.

Regular exercise can help:

  • Improve mood
  • Give you more energy and stamina
  • Sharpen mental focus and memory
  • Improve your sleep
  • Boost your sex life
  • Improve cholesterol levels
  • Help with weight loss (or help avoid weight gain)
  • Build stronger bones
  • Lower risk of type 2 diabetes
  • Lower risk of colon, breast cancer, and other cancers
  • Lower risk of stroke

Sound good? Let’s get moving!

What counts? How much do I need?

Anything that gets your heart rate up counts, and any amount is better than none, but you get the major health payoff at a certain point.

The benefits of exercise really kick in at 2.5 hours a week at a moderate pace (walking, yardwork) or half as much time at a fast pace (running, biking fast or uphill). You can do any combination of moderate or fast too. Use our handy printable exercise log sheet to track how much you get.

If you break this weekly time into 30-minute blocks, you’ll need five moderate blocks or just three vigorous sessions a week.

As you exercise more, you should see even more health benefits. Just watch out for overtraining injuries.

  • For people who like to geek out, the recommendation really is for “500 MET-minutes” of activity a week. Every activity has a MET value, or “metabolic equivalent.” Sitting at rest is a 1.0, walking 3 miles per hour is about 3.3 MET, and running at a pace of 6 miles per hour is about 10 MET.
  • Moderate activity falls in the 3 to 6 MET range, while vigorous is anything over 6 MET. You can look up your favorite activity here and figure out how much jai alai or jump roping you need in a week.

Is cardio enough?

Cardio is great, but don’t forget the strength training. Twice a week, work your muscles against gravity, either using just your body weight or equipment like weights and machines. Strength training helps with coordination and balance; it also builds muscle, which burns more calories round the clock.

Good to know

  • If you’re not active right now, start slowly and ramp up to adjust and avoid injury. (If you’re pregnant or getting care for a chronic condition, check with your doctor before making any major changes or starting an ambitious exercise plan.)
  • Once you’re able to exercise for 30 minutes a day five times a week, try challenging yourself with more time or a faster pace.
  • Feel free to break up your workouts into short blocks, like 10 minutes.
  • Make sure you move often during the day, even if it’s just a minute or two every half hour. Too much sitting is bad for you even if you exercise.
  • Pick something you like to do, since you’re more likely to stick with it. And remember, have fun!

Editor: Deepi Brar

Natalie Lawson, RN is a clinical health specialist at Rally Health. She lives in Oakland, California.

Rally tools

Exercise log sheet (pdf)

Selected references

United States Department of Health and Human Services. 2008 Physical Activity Guidelines for Americans. [Link]

The Compendium of Physical Activities. Website supported by the National Cancer Institute and Arizona State University. [Link]


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