High load, low rep squats fatigue you more than lower load, high rep sets. Everyone knows that.
But is it actually true?
I’ve got a surprise for you: research shows that in trained men, squatting 8 sets of 10 reps with just 70% of 1-rep max caused more than 2 times the fatigue as 8 sets of 3 reps with a scary 90% of 1-rep max.
Just think about it: after all these sets with high-load 180 lbs squats (90%), you may still be able to do 160 lbs squats.
However, after 8 sets of 140 lbs squats (70%), you will probably not be able to do one 160 lbs squat.
Just goes to show: light weights done for high reps are going to need a lot more recovery.
If you’re burnt out, you’re better off doing high-loads for lower reps than low-loads for higher reps.
Study: Bartolomei et al (2018): Comparison of the recovery response from high-intensity
and high-volume resistance exercise in trained men.