The next time you go to the gym, take a look around: you’ll probably see all kinds of exercises, some good and some not-so-good.The unfortunate truth is that not all exercises are created equal. Some are incredibly effective at building muscle and melting fat; others are ineffective and can even do more harm than good. (Worse, the bad ones are sometimes very popular.)
Situps and crunches are as old-school as it gets: You see them in PE class, boot camps and military training around the world. But get ready for some big news because these tummy exercises aren’t effective or good for you.
Your core — which consists of your rectus abdominis, external and internal obliques, transverse abdominis, pelvic floor, etc. — is designed to help your body stabilize and brace against twisting and bending (not generate it).
Situps and crunches, however, eliminate the bracing and put your body into bad positions: You pull your neck forward, round your shoulders, flex your spine and put a lot of stress on your lower back. (It also goes without saying that you should avoid the situp machine too for those reasons.)
Seated twist Machines Remember how the core is supposed to move? Well, the vertebrae of your spine at your lower back can only twist 13 degrees in each direction, which is tinier than one hour on a clock. But the seated twist machines actually crank your body well beyond that range-of-motion.
The back extension machine tries to strengthen your lower back by repeatedly flexing and extending it, which can cause problems. Worse, a lot of people hold a weight plate behind their head or at their chest, which further increases the stress on your spine.
Behind-the -neck lat pulldowns or behind the neck presses
Avoid any upper-body exercise where you pull or push from behind your neck because it puts tremendous strain on your shoulders. In a behind-the-neck position, your shoulders are almost at their maximal limit on extension in those positions — throwing weight on top of it just adds more strain to a fragile area.
Always do lat pulldowns, chin-ups, pullups, etc. toward your collar bones; if you’re going to press a weight overhead, start with the barbell at your collar bone or use dumbbells or kettlebells.