To my knowledge this isn’t know to most of the S&S community so I’d like to share this.
To get straight to the point all you have to do is have 21 or less endurance, and have over 200% equip load. It is impossible to have more than 200% equip load even with the heaviest gear if you have 22 or more endurance. To have 200% equip load the easiest you will need the Ashen effigey shield from the Ziggurat of Dust, and greathammer preferably the Bonecrusher gotten from transmuting crypt keeper ashes with any greathammer and the full set of Titan armor from the castle of storms. You will also want any prayer although the higher the cost the better.
How to perform the glitch
Now that you have everything necessary all you have to do is cast a prayer at over 200% equip load and you will gain focus based on the cost of the prayer, the higher the prayer cost the better since you will get more focus that way. By doing this you will get more focus than your maximum and since focus determines stamina your stamina will increase as well.
As you can see the amount of stamina you get is pretty silly when used with something like divine blessed weapon which only has a focus cost of 40. Enjoy your unlimited stamina and remember to take the armor off after gaining true power. It is worth mentioning that the extra stamina and focus resets after resting which is the only real downside to this.