... Training In A Whole New Way... Prepare to make your muscles quake.

Consistently hit up the gym: Check! Crank out multiple strength training workouts weekly: Check! See results over time and feel like a total badass: Check and check! If you're checking all these boxes, it's time to officially take your fitness regiment to the next level, and get the most bang for your workout buck. How exactly? With a technique that works your muscles as they lengthen in addition to when they contract, called "eccentric training."

What it is: Emphasizing the lowering portion of a rep. Also known as "negative training," the technique increases the time your muscles are under tension, which helps boost muscle fiber activation.

The benefits: Higher calorie burn both during and after exercise; fewer injuries, as it strengthens tendons and helps muscles absorb high-impact stress (like running); and a new study says it can help you break through strength plateaus in five weeks.

When to do it: Once a week, swap out one of your three strength-training workouts with this routine. Complete the circuit in order, moving from the first exercise to the next and resting as needed in between. Repeat once for two total sets. After three weeks, take one week off, then continue with heavier weights.

Your trainer: Exercise physiologist Joel Seedman Ph.D., owner of Advanced Human Performance in Atlanta

DEADLIFT TO SINGLE-LEG ROMANIAN DEADLIFT

Squat to grab a barbell with an overhand grip (a). Thrust your hips forward as you rise to stand (b). With your right knee slightly bent, lift your left leg behind you, hinging at your hips and lowering your torso until it's parallel to the floor (c). Reverse the movement to return to start. That's one rep; do three or four, then switch sides and repeat.

NEGATIVE PULLUP

Place a bench under a chinup bar, then step onto the bench and grasp the bar with an overhand shoulder-width grip; jump up so your chin is above bar level (a). Pause in the start position, then, bracing your core, take three to five seconds to fully extend your arms (b). That's one rep; do four or five.

BULGARIAN SPLIT SQUAT

Stand with the top of your right foot on a bench behind you and hold a dumbbell in each hand at your sides (a). Keeping a tall chest, take three to five seconds to bend both knees to lower your body as far as you can (b). Pause for three to five seconds; return to start quickly. That's one rep; do six to eight, then switch sides and repeat.

NEGATIVE SKULL CRUSHER

Grasp a dumbbell in each hand and lie on a bench with your arms reaching toward the ceiling (a). Slowly bend your elbows to bring the weights to the sides of your forehead (b); pause, then, with elbows bent, lower arms to bring the weights above your chest (c). Press weights up to return to start. That's one rep; do six to eight.