I’ve often wrote and talked about the importance of single leg training. Single leg exercises—think lunges, split squats, RFESS and the like—train strength, stability, balance and range of motion. The following is true for all strength training exercises: after a certain point, loading it become challenging. With these single leg movements, it basically becomes really hard to hold the weights.
Loading the right weight is important because if it isn’t challenging enough, are you getting enough stimulus to grow more muscle or bone? Probably not. Knowing or finding the right amount of struggle is key.
In trying to help people find the right weights for a set of split squats, I’ve been saying that at the end of your set you should want to chuck those dumbbells to the floor and never touch them again. I'm exaggerating, which the best coaching cues do, by the way. But seriously, if those weights are so light that after doing 20 reps (10 on each side, to clarify), you hands should be fried and your forearms screaming.
It’s also normal that these heavy, annoying weights should pull you off balance. In fact, you’ll probably wobble at least once per set per leg—and that isn’t a bad thing! It likely means you’re being challenging appropriately. No wobble, probably too light. Whereas only wobbles are probably too heavy.
Without further ado, here is a set of split squats I did yesterday. It’s 1 minute and 25 seconds long. You’ll see the weights are heavy and I wobble a little bit. I have to grind out some of the reps. You can see the struggle on my face. I did 3 sets of 10 here, and while they were hard, they were not impossible, I probably have 3-5+ RIR - if I needed them.