In short, being able to keep your hips and spine in an intentionally rigid and stable position will help you maintain proper body positioning, will help prevent you from swinging and moving deadweight, and will help keep your path to the bar as short and efficient as possible.
Pull ups are a great way to work your back, your arms, and your core muscles. If your core muscles are weak, you won't have core stability and strength necessary to pull off a successful, non-painful pull up.
Pullups use your lats and biceps primarily, while also recruiting your deltoids, rhomboids, and core. These are the muscles you'll need to strengthen.
But having a strong core, and bracing properly for the movement are both important. The pull-up is not just an upper body exercise, and an exercise where you can essentially disregard the rest of your body. The pull-up is a full body exercise. So remember, a strong core absolutely matters.
Lyons suggests two quick at-home tests to determine whether or not your core is weak. "You should be able to hold a hollow hold—your low back is pressed into floor, legs and arms hovering in the air, and core ignited—for at least 10 seconds. And you should be able to hold a plank for at least 50 seconds," she says.
Some people are strong when they lift weights but can't effectively perform pull-ups, push-ups, lunges, burpees, and endurance exercise in general. Previous injuries like a torn rotator cuff, a torn labrum, or torn biceps that keep them from hanging from objects for extended amounts of time.
As a rule of thumb, most people have weaker pulling muscles. This is often due to people not training their backside as seriously as their mirror muscles. It can also be due to the fact that their mind-muscle connection with their back is bad, causing them to rely mostly on arms to pull themselves up.
If you practice 1 or 2 reps with additional weight (10 or more pounds), bodyweight pull ups start to feel a lot easier. Your nervous system adapts quickly so that you can do more pull ups. Of course, you need to be careful. Don't train to failure.
If you have weak core muscles, you may even find that your stomach sticks out further than your chest. This core strength sign is an indication of loss of core tone and a weak core. This core strength sign can be caused by core muscle weakness, pregnancy, or an increase in body fat around your core.
When we're talking specifically about strengthening and building your ab muscles — not necessarily seeing them – "it can take anywhere from four to eight weeks, depending on what exercises you're doing and your eating habits," said fitness coach Nick Leyden, MS, CSCS. (More on those aspects later.)
"The reality is while you are crunching your way to strong abs, you can actually be overworking your core and causing back pain and poor posture," she tells me, reiterating the importance of having a strong core, since it's the "main support for your spine, organs, pelvic floor, and entire body."
Tilting or swaying side to side while walking is a telltale sign you've lost some core strength and stability, especially lateral (side) trunk stability, Schwabe says. “Your core is supposed to resist against other movements and stabilize so your shoulders and hips can move around it,” he says.
One good way to start is to inhale, and as you're doing that, imagine you're bringing your belly button toward your spine. Hold your muscles tight in that position for a few seconds. This feeling of braced stomach muscles is what it feels like to engage — or tighten — your core.
Bottom line. Your ability to achieve a visible pack of abs — whether a four-, six-, or eight-pack — is largely determined by genetics. However, healthy lifestyle choices, like losing belly fat and exercising, can provide anyone with a fit and toned abdomen. A strong core also helps with overall strength and balance.
The most common reason for not having visible abs is simply that your body fat is not low enough, simply there is fat between your skin and muscle which is blurring or obscuring the lines and definition of your six pack.
Your exercises are too easy
Choose exercises that are challenging for you in order to make strength gains. If you're still doing core activation exercises, heel slides and bridges months after having a baby or a new injury, it's just too easy. It's not that you'll lose strength, but you won't really gain any either.
"A strong core means the ability to lift more weight," he explains. "Strong lifts require a great deal of stability and core strength to execute with proper form."
A toning style core routine can be performed 4-6 days per week once you have built up your tolerance for those exercises, but if you become overly sore you may need to take a 48 hour break to allow muscles to properly heal. Just make sure you take at least one day off each week, even if you never get sore.
An overhand grip pull-up is the hardest to do, because it places more of the workload on your lats. The wider your grip, the less help your lats get from other muscles, making a rep harder.
If you are a beginner with no training experience, you will likely be unable to do a single pull-up. However, fit and active men should be able to do at least 4 to 8 pull-ups in one set. Fit and active women should be able to do at least 1 to 3 pull-ups in one set.