In the past 2 months i've recorded a feature and recorded for additional photography on a feature both with a torn ligament in my left foot. The damage actually came from running 5 miles in order to recover from a 20hr day two days prior. I managed to get through it ok (still have remenants of the pain) but stress levels were definitely increased because of the injury. I used vet wrap to support my foot and used ice baths (in the evening)+ cooling gel for swellings plus deep heat and some iboprufen rub for the pain/ache. I did (before the injury) run at least 12 miles per week and used to do a reasonable amount of biometric exercise - crunches, the plank, sit ups, diamond press ups, various stretches etc every week. I do think exercise is invaluable for both the recordist and definitely the boom op but i am wary of weights in the gym and over stressing joints in very specific areas. I have been lucky enough to work with a few very high level martial artist (now stunt men) and also had some good advice from my family many of whom are pro rugby players and my sister is an olympic rowing coach. They have all said 2 things that have stayed with me:- 1 is that booming and booming with the bag places the biggest strain on the core so core exercises and posture (straight back) exercises are critically important to reduce stress on your back, your arms and therefore your brain. 2- The happy face sad face principle - which is any exercise or exertion you do in one direction you should do the same amount or at least try in the other direction. So being pulled forward all the time needs to be counteracted with exercises like 'supermans' which is basically pulling yourself back. A good friend of mine who is/was also a sound man has recently had to retire due to massive back and leg problems and he's younger than me. So i think you can never underestimate this issue, i'd rather have an injury i can fix than a condition which i have to manage.