By now, if you’ve been listening, you know you need to add some form of cardio to your routine in order to keep shredding fat and building lean muscle. This qualifies as conventional wisdom by now, but when you look at the big picture, all you’re really doing when you think about the cardio you have to do is adding yet another variable to an already difficult-to-decipher mix—and since getting in shape isn’t supposed to be rocket science, things can get seriously frustrating.

So, what to do?

One way to fix what’s wrong in the gym—and to correctly plot out your own training—is to observe the mistakes of others. The next time you’re in the gym, take a look around and see what sort of cardio work people are doing. If your gym is anything like mine, the majority of what you’ll see will fall into the following two categories:

  1. Not enough work. This is the collection of people you’ll see drinking coffee and reading their newspapers on recumbent bikes. You’ve probably made fun of them before, and they’ve deserved every bit of it because they’re not doing anything of substance. They’re not paying attention, they’re not varying their routines, they’re not planning out their training, and they’re getting nowhere, week after week and year after year.
  2. Too much work. These are the people you’ll see doing cardio until they drop. Literally. For them, getting on a treadmill or an elliptical is a do-or-die proposition where they truly believe they’re not getting an effective workout unless they turn a half hour of cardio into a torture test where they’re hanging on for dear life until the very end of the countdown timer’s allotted period. Then they turn around and do it again the next day. They’re going too hard, doing too much, and they, too, are going absolutely nowhere.

Simplified, an effective fat-burning, lean muscle-preserving cardio program can be broken down into two simple forms: steady-state cardio and high-intensity interval training. In order to accomplish the goal of getting or staying lean while not eating away at your hard-earned muscle, you’ll need to perform a combination of both on a weekly basis. Here’s how to do each.

Steady-state cardio

The idea behind steady-state cardio is to work at about 60-70% of your maximum heart rate for an extended period of time—anywhere from 20 minutes to an hour. Over the years, this has been referred to as the “fat-burning zone,” but that’s not why you should be doing this sort of work.

Find your maximum heart rate—approximated—by subtracting your age from 220, then work within the allotted range.

When you work your heart at this rate on a regular basis two things happen. First, you’ll be strengthening the left ventricle of your heart, and thickening its walls. As a result of this strengthening, you’ll be increasing your heart’s stroke volume—the amount of blood that’s pumped with each heartbeat. When a single beat of your heart pumps more blood, your body works more efficiently—and more oxygen is spread throughout your body.

There’s a name for this. It’s called “getting in shape,” and it should be done at least four days per week. You can use any machine you want, but my favorite method of doing steady state is to simply jack up a treadmill to the highest possible incline and walk at a pace that keeps my heart rate between 125 and 140 beats per minute. I measure this by placing my hands on the sensors that come with most modern treadmills. I’ll do this for 30 minutes each day, usually before I lift weights, and the benefits of this work have been incredible in terms of improved body composition, better sleep and an improved feeling of overall well-being. Best of all, I’m recovering faster than ever, and I’m capable of doing a lot more work in the gym.

At this 60-70% intensity, you can do steady-state cardio 5-6 times a week. For beginners, start out with 20-minute sessions, four times per week, and work your way up from there.

HIIT

HIIT, simply put, is sprint workshort bursts of all-out effort followed by short rest periods. This is what really burns fat and gets you in shape, and it’s where you can have fun and add limitless variety to your training.

The goal here, again, is to go all-out, with everything you have, for a short period of time. An easy example of this is the treadmill sprint. Set a treadmill to the highest possible incline, then dial the speed up so you’ll have to sprint. Run for 10 seconds, then stand on the rails for 30 seconds, then run again. You’ll essentially keep doing this until you’re gassed out.

These types of sprint sessions can be done several different ways: outside with regular runs, on the elliptical, on a bike, or through barbell, dumbbell, kettlebell, or even bodyweight circuitspretty much anything that requires a short period of heavy, repeatable effort followed by a short, controlled rest period.

If you’re just starting out with this type of cardio, limit HIIT sessions to twice per week, and perform them on your lower body workout days in order to conserve your central nervous system.

Cardio program

Here’s an example of how to add this mix of steady-state and HIIT cardio to a conventional 5/3/1 upper body/lower body split:

  • Monday: Steady-State, Lower Body Weights, HIIT
  • Tuesday: Steady-State
  • Wednesday: Steady-State, Upper Body Weights
  • Thursday: Steady State or Off
  • Friday: Steady-State, Lower Body Weights, HIIT
  • Saturday: Steady-State
  • Sunday: Steady-State, Upper Body Weights