"Feel the burn,” of course, refers to the deep-down ache you feel in a working muscle as lactic acid builds up to searing levels, at some point leaving you unable to continue a set.
Chasing that sensation is the goal of “burn sets,” which tack a final, excruciating set using lighter weight to achieve utter muscle failure onto the end of a bodypart workout. But the question remains, How effective are burn sets and how can you get the most out of this technique?
We tapped Dave Looney, Ph.D., CSCS, an ORISE research fellow at the U.S. Army Institute of Environmental Medicine in Natick, Massachusetts, and an expert in the exercise physiology field, to find out.
Rule No. 1: Know the difference between a drop and a burn.
Drop sets and burn sets are terms often used interchangeably, but there are nuanced differences between the two. “Drop sets are consecutive sets performed with progressively lighter weights with little-to-no rest periods between sets,” explains Looney. “For instance, you start with 100 pounds, do it as many times as you can, then drop the weight immediately to 80 or even 50 pounds, and continue repping,” he says.
A burn set is one final set of an exercise done with a lighter resistance than your previous set performed after you’ve completed your pyramid set/rep protocol. “It���s one last ‘money’ set, where you’re doing as many reps as you can [with a given weight] and then stopping,” Looney says.
Rule No. 2: Don’t skip heavy sets.
If you’re training to add lean muscle mass, a burn set isn’t ideal, Looney admits. “It’s beneficial if you’re trying to develop muscular endurance, but our research showed that heavy resistance exercise activates much more muscle mass than light resistance exercise, even if you are doing that light resistance exercise to failure or if you’re pre-fatigued.” In other words, training adaptations are specific to the training stimulus.
Rule No. 3: Choose proper resistance.
Sometimes more is better — but not for burn reps. “Research has shown that if you use less than 65 percent of your one-rep max, it might not be heavy enough to stimulate any muscle growth,” Looney says. “The ‘sweet spot’ for growth is a weight with which you can get at least six reps, but no more than 15, before failing.” This range sets the stage for growth adaptations. “If you use too heavy a weight and you’re only getting a few reps, you won’t get all the anaerobic stress and muscle damage as you would in that ideal zone,” warns Looney.
Rule No. 4: Don't be afraid to fail.
If you're afraid to lose control of a heavy load, Looney advises a different approach: For example, if you’re wary of doing a bilateral exercise such as barbell squats to failure, try a dumbbell unilateral squat instead. “You’re handling less weight while still getting a lot of intensity and stimulation,” says Looney. “And it's much easier to control and recover if you fail with dumbbells in your hands than with a barbell across your upper back.”
Rule No. 5: Don’t overdo it.
Burn sets can be brutal, and not just the day of. “Plan for an extra day or two of recovery before hitting that area again,” Looney advises. “Normally, muscle soreness peaks around the 48-hour mark, but you might still be sore three days later. Listen to your body — if you’re still really sore, it means you’re still in recovery mode.”
Rule No. 6: Failure or bust?
Failure may seem like a critical component of a burn set, but it’s actually not always necessary. “In a burn set you’re pushing a muscle to the limit, activating the muscle fibers to the point of failure,” Looney says. “But if you come up a rep or two short of failure, there isn’t a substantial difference in the effect on the muscle.”
That said, a side benefit of striving for failure is determining your true ability. “It gives you a solid performance marker, and if you’re comparing one week to the next, you can know whether you have improved upon your total weight and reps,” says Looney.