Strength and Stealth are two of GTA Online stats whose ways of increasing are somewhat obscure and this guide should lead you through getting the first one up to maximum without too much trouble or time wasted, without using any exploits.
GTA Online players usually rely on exploits or modders on PC for increasing Strength these days but there is a rather easy way of increasing the stat without doing either or even requiring a partner.
Strength is increased by one per cent for every 20 punches you land, meaning you need to land 2,000 punches in total to max the stat out. In other words, you need a whole lot of NPCs to punch in a period of time that is as short as possible.
Where and how to increase Strength quickly in GTA Online
This is where Vespucci Beach comes in. It is a highly-populated area in GTA Online and the prime location for punching people 2,000 times. The number may sound a bit scary at first but levelling the stat goes faster than you might expect.
The first step is to make your way to the location, seen on the map below, or on the link above.
Pick one of the three lanes to go along and punch a bunch of people. The red line is the most populated one during the day but if you clear it, you can circle back across the green one as it also features spots with huge groups of NPCs. During the night, the blue line is your best bet, on the boardwalk near the Ferris Wheels.
You can see an example of a large group of NPCs on the image below.
From this point on, you can do two things - start punching or call Lester, pay $5,000 to make Cops Turn a Blind Eye and then start punching. If you decide to pay Lester, you will get three minutes of uninterrupted punching so this is highly suggested when you run into a group of 10-15 NPCs.
If you happen to start punching before calling Lester, cops will eventually show up but it's better to just ignore them and keep slapping people around. They will eventually kill you but trying to lose them is just wasting precious time. Just start punching people again when you respawn.
As soon as you punch one, most will start running away while a few others will either try to fight back. The best way from here is to sprint towards and NPC and punch sooner than they are actually in your normal reach since this will cause your character to sprint faster than normal, catch up to them and hit them.
When you see two or three red NPC dots on the radar, it may be time to accept the fight as these will have more HP, allowing you to land more punches before they go down. Beat them up and then continue as usual.
Maxing out Strength by punching people along Vespucci beach will take you about two hours but it eventually becomes addictive enough to make it seem like you didn't spend as much time farming this particular stat.
What is the benefit of Strength in GTA Online?
Strength increases the damage you deal in melee but more importantly, it decreases the damage you take, which can be highly beneficial at lower ranks when your health pool isn't that big. Furthermore, it will cause you to lose less armour upon being shot, which should keep that low supply of armour just about enough to last through a heist.