When beating egg white until the egg white becomes stiff you beat the egg white for at least 5 minutes.
When beating the egg whites with a hand mixer it takes around 5 minutes because it can take while for the sugar to dissolve and for the egg white to become stiff.
You could also beat the egg whites using an electric mixer which will beat the egg whites up within a couple minutes instead of using your hand mixer.
I prefer to use the electric hand mixer to beat the egg whites faster than doing all the work using a hand mixer alone.
It saves the pain in my wrist and arms although it's a good workout but you could get carpal tunnel mixing the egg whites by hand.
An electric hand mixer is a wonderful kitchen product to have.