Do only what makes sense to you
I believe that people who build their work in accordance with their values rarely burnout. As a famous quote says, "Find a job you enjoy doing, and you will never have to work a day in your life." I obtained three higher education degrees and tried several professions until I found something that reflects all my values. It gives me plenty of life energy, and this compensates for even the strongest fatigue.
We think that the more we work, the better we perform. That is not always the case. We need to give ourselves time to restore and recharge. Do activities that allow you to let go and switch gears (golf, knitting, cycling — whatever works). Even if we love what we do, our body and mind need a rest from it.
Changing the settings in which we work is very useful as well. For those who can do so, try to find new inspiring places to work. For example, I am more productive in sunny weather, so when winter starts in Switzerland, I usually take a trip to California or the South of France for a few weeks to recharge.