Do the maths
This is my favourite gym mistake, mainly because it wasn’t just my fault.
I was doing a powerlifting course for eight-weeks leading into a novice competition.
The heaviest weight plates in most commercial gyms are 20kg, which means most of your gym-maths is based around this and a 20kg bar.
Powerlifting gyms also have 25kg plates which are the same sizes as 20kg plates, but usually in a different colour to avoid confusion.
My training partners for the session had a similar background in commercial gyms.
We all knew what 25kg plates were, but we rarely used them.
So there we were bench pressing away and working up to heavy sets for the session.
One guy was a bit stronger than me and his goal was to hit sets of five reps at 110kg.
I was a touch stronger than the other training partner with us, so we had a variety of plates that were getting changed for each lifter.
We had 1x25kg plates on each side of the bar and then adjusted the weights to suit.
I was first, lifting around 100kg.
Then the other guy went at about 90kg.
Then we went back to our strongest guy who was meant to lift his 110kg.
He got set up, unracked the weighted and proceeded to get two reps.
The third rep was slow, but he just made it.
The coach looked over and saw that it was hard, which it wasn’t meant to be.
Then he looked at the plates and knew why.
This guy had put on 25kg plates instead of the 20kg plates, so he was lifting an extra 10kg.
The best part is that he had never done one rep with 120kg, but now he had just done three!
So he hit a PB without even trying.