Action: Start by leaning back slightly—this is the top position of the movement. Next, break your knees slowly and lower your body as far as you can without falling backward. If you feel like you’ve gone too far, you can use your supporting hand to pull yourself back up. Once you reach the bottom of the movement, push yourself back up to the top without “locking out” and repeat.
Listen to your body. If you have a training day scheduled on paper but feel like rubbish, a day off focused on quality nutrition and adequate rest might actually improve your results. After all, you damage muscle in the gym; you build it with quality rest and nutrition. Pushing through when you're overly tired can be a recipe for disaster or injury.