If you work out consistently, you probably feel like you’re crushing your cardio. After all, cardiovascular exercise involves moving the large muscles in your legs, arms, and hips over a sustained period of time. That might just look like putting your body in motion, and to a certain extent, that’s what it is.   

But the most effective cardio exercise is not solely about moving from A to Z. It’s about improving heart and brain health, helping to regulate your weight, boosting immunity, and — a bonus if you’re a Spartan — ensuring you bring your A-game to every race.

But to achieve all of that, you really need to make sure that you’re truly maximizing your cardio workouts, and not unintentionally screwing them up instead.  

Related: 6 Ways to Start a Running Routine That Sticks

According to Anthony Ferguson, owner of Ferguson Fitness, that means keeping a handle on the acute variables — frequency, intensity, and duration — of your training as well as ticking the right boxes on how you begin and close your cardio workouts.

Necessary Components and Acute Variables of the Best Cardio Workouts

Warm-Ups and Cool Downs

“Warm-ups and cool downs are an essential part of your workout, but are often skipped or neglected,” Ferguson says. “The purpose of a warm-up is to prepare the body for what’s ahead, both biomechanically and physiologically. 

"Your cardiovascular and musculoskeletal systems need a period of time to ramp up or scale down to meet the physical demands of the workout or bring the body back to neutral and begin the recovery process.”

Related: The 10 Dynamic Warm-Up Exercises That No One Wants to Do

You can include some static stretching and mobility exercises in both warm-ups and cool downs, as both will support quick muscle recovery. 

“Spartan workouts typically work the entire body, so movements to open up the shoulders, hips, and knees such as walking lunges, bodyweight deep squats, and inchworms are definitely recommended,” the personal trainer and Spartan SGX coach adds.  

Cardio Workout Frequency

The American College of Sports Medicine (ACSM) advises performing cardiovascular training three to five days a week, depending on duration and intensity (which we'll get to later).

Doing this day-in, day-out might seem like a tough ask. However, one of the best ways to maintain a consistent routine is to bring a little variation to the exercise mix.

“The great thing about Spartan workouts is that you can incorporate both cardio and strength training in fun and unique ways,” Ferguson explains.

If you train frequently, adding swimming to your schedule is a no-brainer. A lower-intensity activity that's easy on your joints, swimming strengthens your heart and boosts your power in the same session.

Related: 5 Reasons That Swimming Needs to Be Part of Your Training Plan

“I felt great at last year’s West Virginia Spartan Race after swimming regularly all summer,” Ferguson says. "But, the best form of cardio is the one you will do consistently, so pick your favorites and stick with them.”

Cardio Duration

Most effective cardio workouts range between 20-60 minutes, but as the primary aim of cardiovascular exercise is to build endurance, training longer is better than training harder. That’s not to say that a 15-minute (or less) workout won’t reap you any rewards (because it will), but training for a Spartan race requires mimicking the conditions you'll face out on the course, at least for part of your training.

Related: Want Better Sleep? Go for a Run.

“Spartan races can last anywhere from 45 minutes all the way up to six or seven hours (or more, especially if you're completing an Ultra)," the trainer explains. "This requires the athlete to have an efficient cardiorespiratory system and high levels of stamina.”

So, as you train, push yourself to go a little longer at least once a week. Whether you’re running, cycling, or swimming, add in some speed work for short sections of your training, as this will help you handle moving at a slower pace for longer.

Cardio Intensity 

Finally, it’s important to ramp up intensity as you progress with your cardio training.

“Training at the proper intensity is essential to get the best results from your cardio workouts,” Ferguson says.

Quoting the ACSM, he explains that cardio sessions should last between 20-60 minutes at a range of 65-90% of an individual’s maximum heart rate.

“To estimate your maximum heart rate, subtract your age from the number 220,” he says.

Bumping up your workout’s intensity levels could mean adding hills to walks and runs, as well as jumps and sprint intervals. And if you can, try running or hiking with obstacles, Ferguson suggests.

Related: How Many Sets Should You Do Per Week to Maximize Muscle Growth?

“Other great ways to build Spartan stamina include hiking with or without a weighted vest or pack, hill repeats, animal movement intervals such as bear crawls, and bucket/sandbag carries,” he says. 

“HIIT or interval-style training includes short intervals of high-intensity training followed by recovery intervals, and it’s another option for optimal cardio conditioning, especially if you are short on time. That's why the DEKA training system is one of our favorite HIIT style workouts to cross-train for Spartan races.”

Of course, the best cardio workouts aren’t solely about what you do during training. It’s also necessary to rest, recover, and refuel properly. But as long as you are sleeping and eating well, fine-tuning your acute training variables can result in reduced risk of disease, increased energy, a better (and likely longer) life, and — of course — crossing the finish line strong.