If you walk into any gym in the country, you will see people making the same mistakes over and over again, and the biggest mistake you will see people making when performing barbell and dumbbell curls is lifting weights that are far too heavy for them.
Dumbbell and barbell curls are two common exercises that are pretty easy to master with regards to form and technique (check out the video below to see how to do bicep curls with correct form), but as soon as people lift exceedingly heavy weights, correct form goes out of the window.
You can usually see the strain in their faces when the weight is too heavy, but the really worrying thing is that they will often bend their back (and sometimes lean right back) in order to get more leverage, and this can easily lead to injury.
Plus you will often see people bringing their elbows away from their sides and getting in all sorts of dangerous positions in order to bring the dumbbell or the barbell up to their shoulders.
So they are obviously far more likely to suffer an injury if they don’t practice correct form, and the only way to guarantee perfect form is to lift weights that are manageable.
Of course you will need to keep on lifting heavier weights in order to progress, but you need to do so in a slow and steady manner.
If you can now manage to do 3 sets of 8 perfect barbell curls at 30 kg, for example, it’s best to move up to 32 or 32.5 kg and see if you can lift this weight with perfect form rather than move straight up to 35 or 40 kg and risk getting injured if you end up struggling to lift them.
It has to be said that it is usually men who are guilty of this because it’s all about ego. They don’t want other people in the gym (particularly girls) seeing them lifting light weights. They want to be seen lifting really heavy weights, even if it is patently obvious that these weights are far too heavy for them.
Anyway I just wanted to point this out because you can still reach a point where you are lifting really heavy weights with perfect form, but it doesn’t happen overnight.
You need to gradually increase the weight over time because this will ensure that you don’t injure yourself and possibly put you out of action for good because it’s very easy to arch your back and do some serious damage if you’re not careful.