The prone plank is one of the most commonly performed (and unremarkable) exercises in gyms across the country. For those of you who aren't familiar with it (really?), you get on your elbows and toes and use your abs, glutes and various core muscles to support your bodyweight.
It's the among the most basic core stability exercises you can do and carries a lot of value in teaching a client how to properly engage their abs and glutes to support their bodyweight instead of just letting everything hang on their lumbar spine.
While this is an important exercise to teach people, I have to ask the question: why do we continue to have clients hold the plank for as long as possible?
I see, very often, trainers asking their clients to hold the plank for a long-ass time. "You did 65 seconds last week, lets get 70 this week". Adding time to the plank is not the same as adding plates to the squat. Those extra 5 seconds aren't really doing anything for your client except increasing the amount of time you get to sit there and look at your watch. Above a certain amount of time (my threshold is a great 45-second plank) I feel that continuing to hold the plank is providing diminishing returns. The client will continue to get more and more tired and their form will diminish significantly. They'll be able to fight to stay up, but they'll do it with crummy form. Comparatively, you wouldn't have a client work up to a 225 deadlift and then simply see how many reps they could add each week, would you? (I hope not).
No, you'd add weight to make it harder and find other variations to build up their standard lift. The same should go for the plank. After my clients prove a particular amount of efficacy with this exercise I will simply move them on to a more difficult variation that they will continue to receive benefits from.
Here are some of the progressions and variations I like to work through:
The first progression I take people to is the one I call the foot-march plank. Essentially you're in a plank position and you alternate lifting each foot for a brief second (the video shows them holding it for a bit longer than I do). The point here is to keep your hips down in the ideal plank position rather than jacking them up into the air.
Next I'll progress up to the arm-march plank, which is a bit more difficult. It's very similar to the foot-march plank since you're taking away a point of support and adding in an anti-rotation component. This one is pretty brutal and you can get some good life out of this one.
The follow up to this one is the plate-switch plank, which starts to add some external resistance. This can also be done by sliding a plate or a sandbag under your body. This, again, appears to be a pretty subtle change but in reality it feels like a whole different exercise.
The final plank progression (that I'll divulge to you) is one of my favorites, the bodysaw plank. I love this exercise because it requires a ton of core strength to brace yourself as you increase the moment arm through the course of the exercise. This variation itself carries with it about a dozen brutal ways to perform it. The standard is on your elbows, but to make it harder you can use straight arms, put your feet on a plate, use a resistance bad, add tempo or pauses, add a weight vest or even just use one leg at a time.
Don't be hasty with your decision to progress a client to a harder exercise. Make sure they understand bracing and activation and can really use their musculature to support their spine. Give these variations and progressions a shot and see if your clients like it more (and improve more) than just a holding a plank for 2 minutes.
Have a great day and go lift some heavy shit!