Burn Fat and Build Muscle Quickly

Although lower-intensity cardio burns a higher percentage of calories from fat, total calories burned is what counts when it comes to shedding bodyfat, and high-intensity workouts are calorie carnivores.

In a 2018 study, 16 overweight men were put on either a moderate-intensity cardio program or a shorter-duration, high-intensity routine.

After 14 weeks of exercising three times a week, only the high-intensity group showed a significant drop in average bodyfat percentage -- almost 5% -- even though they exercised about 15 minutes less per session. Also, consider that the average 180-pound male burns 220 calories in 20 minutes performing moderate-intensity cardio on a treadmill.

These workouts burn more calories in less time.

Hill Running

Running uphill causes powerful contractions in your leg muscles as they work hard against the force of gravity. It was a discipline much favored in former times by bodybuilders, and today many sportsmen do variations, like running the bleachers, to maintain stamina and strength.

The Workout: After a 5-10-minute warm-up, sprint up the hill 4-6 times, actively resting about 60 seconds between runs (walk or jog back down the hill). Gradually work up to a total uphill running time of 6-10 minutes, which equals around 12-20 reps.

Sandbag Running

The idea is simple: Place a filled sandbag in a knapsack or backpack and run. Using the knapsack eliminates the problem of losing your grip on the bag, which would short-circuit the cardio component of the workout.

The Workout: Carrying the sandbag throughout, warm up for five minutes, progressing from a walk to an easy jog. Next, alternate 30 seconds of faster running with 30 seconds of a slow jog or walk. Do this for a total of 12 minutes, then do a cool-down walk for three minutes.

Farmer's Walk

This staple of strongman competitions will target your trapezius strength while simultaneously taxing your aerobic system. It simply involves walking while holding weights (in our case, dumbbells) in each hand.

The Workout: Warm up by walking without weights for five minutes, then walk with the weights in a straight line for 1-3 minutes. Rest for 90 seconds and repeat. Start with five repetitions, then progress up to 10 reps.

In closing, steady-state, longer-duration cardio ultimately is more beneficial for heart health. These activities present a new challenge to your cardiovascular system by recruiting more upper-body muscles than traditional cardio. So ease into them and after a few months you'll feel and see the difference.