There are two rules for loading a barbell correctly:
1) Always use the largest plates available and
2) Never use more than one set of the same type of plate, unless it’s a 20kg plate.
Most people who are new to lifting (or those who have trained with bad habits for a long time), tend to look upon this as silly, anally-retentive, OCD gym owner nonsense.
Quite apart from making sure that your bar is not offensive to look at, there are 4 very important reasons why you should load it correctly:
1) It helps prevent mis-loads.
You, your coach and your training partners can very easily see and count the weight on the bar when there are 2 plates. If there are 6 or seven small plates on there, that’s more opportunities for potentially injurious mistakes to happen.
There is a standard way to load every weight increment – 60kg is done with 1 20kg plate on each side of a 20kg bar. 120 is 2 20s and a 10 on each side etc etc
If you load your bar correctly every time you train, you very quickly gain the ability recognise and instantly count what’s on the bar. You won’t even think about it after 3 months, you’ll just see the weight.
If you load the bar differently every time, you will have no opportunity to develop this instinct, and you’ll have to stop and count every single time. That slows your workout down, and greatly multiples your probability of making a mistake.
You only need to attempt to squat a mis-loaded bar ONCE in your lifting career to give yourself a very big problem. Therefore, you should train in a manner that makes it unlikely to happen.
2) If the bar needs to be dropped for any reason, the plates on the inside take the most beating, so the larger more durable ones like the 20s or 15s need to go here.
But you never need to drop the bar, right?
Well, as the old saying goes: even monkeys occasionally fall out of trees. Just like mis-loads, it only takes 1 instance of not dropping the bar when you should drop it to create a problem.
If you get in to trouble half way through a lift, you need to be able to bail. You do not need to have an overhead squat disappearing way behind you and be thinking “Oh no! I’d better not drop this because I’ve loaded a bunch of 5s onto each side and I’ll smash them”.
Putting the big plates on is safer, and preserves the equipment.
3) When you load your bar correctly, we ensure there are enough plates to distribute around the whole room.
If there’s a class of 20 people out there, and 5 people have loaded 75% of the gyms 5kg plates onto their bars, the other people in the room have a problem. Not fair.
4) If you’re ever visiting another another gym, loading your bar correctly means people won’t think you’ve been seized by some sort of 5kg-plate-hoarding insanity, and proceed to shun you for your foolishness.