11/03/2025
Want to get stronger? When you’re working out, stop. (and then rest, and repeat)
This week I learned some more about isometric holds and why they are really important for safe workouts. ISOMETRIC means holding your muscle at the same (iso) length (metric) as you’re doing resistance training. So, essentially, holding still in your stress position, rather than moving the weight up or down. Think plank, wall sit, deadlift hold. Or … your three-breath yoga pose.
Here’s why it’s so important.
TENDONS are straps of connective tissue attaching your muscles to your bones. They transfer the force of the contracting muscle to the bone, creating movement (or preventing it). As a tendon is loaded, the load goes first through the strongest fibres. It makes sense for the body to pick the A-team, right? Any weaker or damaged fibres are shielded from the stress of the lift.
If the load continues, however, the stronger fibres within the tendon tire, and the body only THEN recruits the B-team of weaker fibres, giving them a chance to strengthen up. This is why weight training makes us stronger.
How to get injured: load your muscle enough that your tendon recruits weak tissues (the process I describe above) and do it fast enough to rupture the tendon before you can realise that the B-team isn’t up to this match. Go lifting big weights fast, till you can’t.
How to get stronger: load the muscle enough to engage the tendon (this can be 6/10 effort) and hold it there for 20 seconds. Here’s the weird - THEN REST. Seriously. REST and repeat.
Here’s how it works.
If you do this 8 times, 20 seconds on and a minute off, you’ve sent the signal to your tendon that it needs the B-team, and it needs it to be better. 20 seconds is as long as it takes to get your brain to get that instruction. Keeping the stress on after that initial period just increases the risk of injury. So resting and repeating maximises the signal and minimises the damage.
Work smart not hard.
You can read more about Dr Keith Baar’s work all over the internet.