My suggestion based on personal experience is to implement moderate exercises in your daily routine. Especially, if your professional life is more passive, then doing regular physical activities can significantly improve productivity and mental state. Moreover, doing a workout at the start of the day can positively affect one's performance during the rest of it. In this case, you do not need to squeeze out those hundred and ten percent of yourself in that training session. The goal here is to develop a positive routine that affects you in a good way for the long term. This is a way to kickstart the day and boost professional performance by leaving some energy for later. Do not get me wrong here, you are still doing serious training sessions and pushing yourself hard. Nevertheless, it is mental training too. The hardest part here is to get going in early mornings, but when you are there in that gym and starting to move, then you get the great feeling of how energy is compounding. Pro tip: try cold shower after working out and you might be doubling up on those positive mental gains.