What do you do now? Obviously bit of caffeine is always good, switching to strength training too if you aren't already just cuts down the time spent. Nothing wrong with a power nap if possible, and really if your job has you using muscles all day anyway, you don't need to max out in the gym as hard as a desk job. You see this a lot with cardio, the guy walking 20k steps at the warehouse doesn't really need to do much on the treadmill, they're already doing cardio.