Combined with other abs exercises, ab crunches can form part of an effective training approach to develop six-pack abs. Here’s what you should know and how to get the most from them.
To crunch or not to crunch
First off let’s address the whole spinal flexion ‘thing’. While Ab Crunches do involve flexing your spine, it’s important to understand that spinal flexion isn’t inherently “bad”. Combining spinal flexion with compression may pose some risk (e.g., deadlifts, although this isn’t as clear cut as you might think either!), Crunches and the like are low-risk exercises providing you have a healthy spine.
If you have some underlying disk pathology then it’s best to follow the advice of your back pain specialist, otherwise well-performed Ab Crunches have the go-ahead from the safety police. A number of critical research reviews can confirm it, too.
While Crunches offer little risk they’re also useful for targeting your six-pack abs. Ab Crunches when done correctly can form part of a complete approach to training for strong and sexy abs.
So you want six-pack abs?
When we’re talking about six-pack abs we’re primarily talking about the development of your rectus abdominis muscle. Due to its large attachment sites at your ribcage and pelvis, your rectus abdominis acts as a primary flexor of your lumbar spine. Essentially, your rectus abdominis pulls your ribcage and pelvis closer together while flexing your spine. Ab Crunches train this function.
There are other exercises that’ll help you get abs as well. Like Cheesecake Push-aways, and Captain Crunch Throw-aways. But you know that anyway. While some exercises will grow your abs the best, you’ll never see them unless you put that cookie down!
The most effective Ab Crunches
Not all Crunches are created equal. Hundreds of low-tension Crunches done in limited ranges of motion are selling your results short. Instead, there are a few key upgrades you could make to ensure you’re getting the most from them.
Have an internal focus
When we’re talking about muscle development we’re just concerned with putting load across tissues. What the movement as a whole looks like on the outside (reps and weight), to a degree is no indicator of how “stimulating” that exercise is for the muscle you’re trying to target.
Let’s be perfectly clear; to get six-pack abs it’s essential you learn how to isolate and target your rectus abdominis most effectively. Maximizing mechanical tension by placing targeted load through those tissues are key.
You should look to include core exercises within your workouts too, to get the benefits of training your midsection with an integrated approach. These exercises should form the meat and veg of your plan, and will ensure you’re building abs that perform as well as they look. Unfortunately, most integrated core exercises lack the internal focus you can create with isolated movements such as Ab Crunches and Reverse Crunches.
Without knowing how to contract your abs in isolation, it’s the equivalent of wanting bigger biceps without knowing how to bicep curl correctly! Or refusing to do bicep curls because you think chin-ups are enough. For the genetically gifted few, maybe, but for most this closed mindset leaves results untapped.
This is where well-executed Ab Crunches come in. Having a greater internal focus will allow you to better target your rectus abdominis and get more from your Ab Crunches. Replicating the targeted tension you you can create with these can also be applied to other exercises as you get better at it.
Train your abs through a full range of motion
During a Crunch just like any other movement it’s important you train your muscles through their full range of motion. There are of course exceptions to this and we could argue that in some circumstances partial range training is beneficial. In most part, though, overloading a muscle at both it’s full active length and fully shortened position will ensure you receive maximal stimulation.
To get the most out of an Ab Crunch your rectus abdominis must go from a position of maximal length to minimal length:
As you lower your shoulders towards the floor during a Crunch then your rectus abdominis is contracting eccentrically – As the space between your ribcage and pelvis increases then your rectus abdominis is being lengthened.
As you lift lift yourself off the floor during a Crunch it’s made possible by a concentric shortening of your rectus abdominis – As your ribcage and pelvis are drawn closer to each other then your rectus abdominis is shortened.
Use an ab mat or rolled up towel
When you place either an ab mat or rolled-up towel under your lumbar spine it does something quite simple yet special. It creates the perfect environment where your rectus abdominis can move through its full active range of motion. In other words it allows your rectus abdominis to maximally lengthen and shorten.
Placing something in your lumbar groove allows for a full extension of your lumbar spine and anterior pelvic tilt. It allows you to maintain tension in your abdominals while they fully lengthen. This helps to create more tension at greater muscle lengths, which is an extremely potent trigger for muscle growth.
Having a pivot point in your lumbar region also makes things harder as your rectus abdominis contracts concentrically to pull your ribcage and pelvis closer to one-another. Not only is your rectus abdominis force to work harder, but other muscles of your core region are too.
Anecdotally, having an ab mat or towel in the right place can enhance the intrinsic focus we previously spoke about. It allows you to really zone-in on the area and the action you’re trying to perform.
If you’ve never used an ab mat or even a strategically rolled-up towel, then I’d highly encourage you start to. Remember, even the now adored ab wheel roll-out was once considered a gimmick. Once you start doing your Crunches like i’ve already explained then you’ll never look back. And, your abs will never have felt stronger.
Programming Ab Crunches
To develop six-pack abs Crunches are best combined with exercises such as roll-outs, hanging leg raises, decline reverse crunches, and body-saws. These produce the greatest levels of muscle activation in both the upper and lower regions of your rectus abdominis.
Ab mat crunches tend to work best in the 12-20 repetition range, for 2-4 sets at the end of a workout. To save time you can also try “staggered ab training”, and performing sets of abs exercises within the rest periods of non-competing exercises (e.g., between sets of presses or rows etc.). Strive for weekly progression and add load as appropriate.