70%

Never give 100%. That may not sound like good advice, especially in our driven/competitive culture, but honestly after 30+ years of burnout it's the best advice I can give anybody. Save at least 30% of your time/energy for yourself. Nobody else is going to make sure you get what you need - your boss, your coach, your mentor, even your friends and family - no one will ever ask you to do less or only what's necessary. We're trained to push ourselves and others, always. Only you are responsible for making sure you have enough gas in the tank to get to a station after a long journey. Save that last part of the tank for refueling. Nothing is worth running on fumes, nor are you doing anyone any favors playing martyr and driving yourself into a ditch. For myself this has meant gradually accepting that I need downtime to rest, read, and relax - I've made career sacrifices to maintain a healthy work/life balance, and I've made lifestyle sacrifices to live on less. I've also had to start making time for things I always made excuses for never doing - like cooking whole meals, exercising, and sleeping more. Not having enough time for any of these isn't a good excuse. If you don't make the time now you may not have as much time in the long run as you hoped. And while I still struggle to balance at times, I remind myself that my ultimate goal is to meet what I need not just what others ask of me.