I make the point in Target Tendonitis that it’s not the best idea to be on a restrictive diet when you’re trying to rehabilitate a tendon. Ideally, you want a surplus of nutrients available to fix things up, not force your body to choose how to allocate resources between repair projects. Basically, dieting for tendonitis is a bad idea.
I’m not against dieting per se, though. What you eat is supremely important to your health, and various diets are great for accomplishing various goals. It doesn’t all have to be fat loss all the time.
I myself have been dieting (almost fasting) fairly frequently for the past few months. Although I’m definitely carnivorous, I do a five-day long, full-vegan “week” every month and a half or so. During these times, I go down to less than a thousand calories a day, almost totally eliminate protein, throw myself into ketosis, and generally just exist on thin soups and crackers. (You can read about a representative week here if you want.)
Why go through all that trouble? Well, this particular diet accomplishes a number of things. One, you lose a little belly fat each time around…and it tends to stay off. Two, satellite cell production is increased. Nice for us older folks. Three, it’s a break from the regular eating schedule. Four, depending on how you set things up, you can often save money. And five, there’s good evidence that it can increase longevity.
So there are a lot of benefits. But one thing I don’t do during these times is work out with my normal volume and intensity. While I will still generally hit the gym, I only do one or two sets of any given exercise, and I don’t go all-out or anything close to it. I’ll generally use about 85-90% of my normal weight and leave a couple of reps in the hole. These workouts are just to help preserve muscle mass and accelerate fat loss. In other words, I’m using exercise to increase the positive effects of the diet, not build new muscle.
I also don’t try to rehabilitate anything if I have an injury. In fact, if I’m injured and am planning on rehabbing it, I’ll hold off on the diet week until I’m finished.
The bottom line is, your body needs nutrients for both building and repair. The best rehab program in the world will fail if the right building blocks aren’t available. So while I’m pro-diet for a lot of conditions, long-term tendon issues (which are almost always tendonosis, not tendonitis) aren’t among them.