Rucking — wearing a weighted vest or rucksack while exercising — originated as training in the military. Now, TikTokers all over the world are turning this old-fashioned workout into the latest trend.

The simple training tactic — also called ruck marching — is a great way to prepare for trudging with equipment, but it’s also a pretty good form of endurance training.

“The military also uses rucking to improve cardiorespiratory fitness and muscular strength and endurance,” Jill Costanza, MSEd, director of Sports Science for the Detroit Lions, explained to Health.

While ruck marching has been around for centuries, its benefits are now the subject of countless TikTok videos, with users saying they’ve experienced increased stamina and more energy.

“Rucking increases your heart rate, and it’s a great alternative to running. Research has proven cardio fitness improves mitochondrial health, heart health, cognitive function, and it’s a mood enhancer,” Costanza noted.

Although wearing a weighted vest may seem easy enough, if you’re new to rucking, it’s probably best to start with a lighter vest. Proper shoes are important, too; without them, you might find yourself injured.

“In particular, rucking too far, too often, or carrying a load that’s too heavy for your current ability level may cause lower body, lower back, shoulder, or neck pain,” advised Nike.

Rucking might be perfect if you’re interested in a low-impact workout with great results — the ruck can also be used to do squats, overhead presses and other simple exercises besides walking. For more information, visit GoRuck.com.