Back to my 5x5 progress, doing well overall, last week I absolutely killed it, but this Monday and then today just felt... sluggish? I've been eating well, resting well, etc. Don't know what's up but just haven't been there this week. I switched up my pre-workout, but that really should not matter, right? After squats it just zaps all of my energy for the rest of the workout. Any help powering through is helpful.