Why it works: The RDL, as it's known, is primarily a hamstrings move, but it’s also effective in building strength in your glutes, lower back, and upper back. Be sure to feel the "squeeze" in your hamstrings and glutes as you raise and lower the bar. For an even tougher variation that'll also increase your grip strength, try doing tempo RDLs—count a few seconds on your way up, and on your way down.
Let's get one thing clear: It's all about the bum. Sure, built biceps fill out a shirt and six-pack abs are the prize of every beachgoer, but the back is where it's at. A bodacious booty is essential to a good physique—and not just for stage-bound fitness contestants. Everyone seems to want a great bum. Photos of posteriors flood the Internet and are often the most viewed—and "liked"—body part on social media. There's just something magical about a beautiful butt!
If you touch your phone between exercise sets, it better be to set its timer to 30 to 90 seconds. When lifting for hypertrophy, rest periods of 30 to 90 seconds encourage a quick release in muscle-building hormones (including testosterone and human growth hormone) while also making sure that you really, truly fatigue your muscles, according to Fitzgerald.
But muscle can’t turn into fat, just like mud can’t turn into gold. If you quit lifting, your muscles mass will decrease over time because there’s no training to stimulate your body to keep it. And your body-fat level will increase if you don’t start eating less (since you burn less). The obvious solution when you stop lifting is to also stop eating so much.
How to do it: Lie on your back with both feet planted firmly against the flat base of a Bosu ball, knees bent. Stabilize your body. If you’re feeling a bit wobbly, your arms can hover on either side of you in case you fall in one direction. If you feel balanced, raise your arms straight up above your chest, hands clasped to challenge and work your stability. Drive your hips toward the ceiling, then lower and repeat.