torsdag 21 juni 2018

Gamifying Timed Static Contractions with Phidget Load Cells

Arguably, the very best lower body resistance exercise you can do is the squat (even if it, of course, in a balanced and varied training program should be complemented with at least calf raises and deadlifts) and the very best way to perform the squat is either on a leg extension machine - if you're inclined to machines - or with a barbell in a smith rack with a well-educated trainer that you trust and respect as an extra, intelligent spotter aside of the, by comparison, rather dimwitted rack - if you're more of a fan of free weights (or why not alternate between them?).

However, both of these alternatives normally require access to a well-equipped gym. So what if you prefer to train at home? (Either because of limited time, little money, cheapness, shyness, or any other imaginable reason for not going to the gym.)

Well, if you're just starting out, or sedated, body-weight squats will take you quite far, but once you can easily handle more than 90 second under load even in the deeper, harder range of motion of the squat, the next natural progression, the unilateral one-legged squat, is still likely to be out of reach.

So what do to when your grip or arms give up before your legs do when holding heavy dumbbells to increase the resistance for the squats? Or you don't want to pre-exhaust your grip and arms during the squats when you do upper-body pulling and pushing exercises afterwards?

Try Timed Static Contractions (TSC). On http://baye.com/qa-isometrics-muscle-mass/, you can see Drew Baye perform his TSC Band Squat and on http://baye.com/qa-bodyweight-tsc-grip/ you can see Steve Maxwell perform his "hip belt squat" with a gi belt. Baye attributes the development of band squats to Maxwell. It's from Baye I've learned about TSC, especially through his thin but informative book "Timed Static Contraction Training" but when searching for the photo of Maxwell, I saw that he has written a book on functional isometrics, too.

The benefits of TSC training with a band such as a towing strap includes:
  • you just need one piece of cheap and light equipment (the towing strap) that you can easily bring with you everywhere
  • that means that you also can perform them virtually everywhere
  • as long as you ease into your contractions, it's a very safe form of training
  • if you also follow the protocol with a moderate first phase, followed by a second phase of ~75% of effort before the final, all-out, maximum effort contraction against the unyielding band, the pre-exhaustion during the first two phases make it virtually impossible for you to hurt yourself during the max-phase
  • strictly speaking, the mode of resistance training doesn't matter: you can develop increased strength, bigger muscles, and improved conditioning via all kinds of different ways of resistance training, including TSC
However, there are a couple of troublesome drawbacks with TSC as well:
  • don't get fooled by the simple set-up - they are hard to perform. If you've done them right, you should have trouble keeping the maximum effort throughout the complete last phase. You need to have the resolve to work through the pain and your brain screaming at you to ease off. Basicallly, you should be so spent afterwards that you should have trouble to remain standing.
  • furthermore - they are boooooooring as hell. Try to keep focused and concentrated on keeping up the necessary effort during 90 seconds - it's harder than you think. That's my main challenge. My mind starts to wander (what's for dinner? Mmmm, dinner... What about that deadline at work?) - and as soon as my concentration wavers even for a split-second, so does the intensity of my effort in the contraction phase I'm currently in, my muscles get some unintentional rest and sabotage the full result of the workout.
  • they don't offer any form of feedback to gauge your effort by. Hence, you have no way of knowing whether you're progressing or unconsciously holding back so you're really plateauing or even regressing.
To combat the last two drawbacks, what if we can gamify it somehow?

Enter a couple of Phidgets load-cells and a Phidget bridge to connect to one's laptop, as well as some nylon webbing, webbing lock, and carabiners to connect the load-cell to the person.

(And to be fair: I am far from the only one with this idea. For instance, "Matt Manning" wrote in his comment from January 3, 2018, on http://baye.com/qa-mmf-tsc/: "I’m measuring force via a load cell plotting a graph on a laptop." - which is pretty much exactly what I'm doing, too.)


The small loops are for one's feet, the big, loosely tied loop goes around one's waist. The webbing lock is to be able to adjust the length in order to get the right bend in the legs (thighs parallel with floor is too deep as gravity will be a too big factor to overcome, almost standing straight is too high, but thighs around 45 degrees angle to floor is a good stance). I've tried to get the webbing lock in the small of my back, in order to avoid it digging into my hip or thigh. To have it close to one of the load cell carabiners would work, too, but I find it gets a bit unbalanced.

So how do we calibrate the load cells and get a plot going to be able to perform the TSC Band Squats with feedback? That will be the topic of an future blog post (when I've had a chance to try it out for a while and workout the kinks).