ache on the outside of my shin

[VeloVT]

I developed a bad case of peroneal tendinitis training for a marathon last year (in my case it was an acute injury caused by a bad footfall but it's often an overuse injury). I also found massage to make a huge difference -- they did something called "postural release therapy" on me that was painful but very effective.

I am very diligent now about stretching my calves, as tight calves seemed to slow my healing & aggravate the condition.

Stretching all of the major muscles in your legs helps too.

There's a stretch you can do with a rope that I found useful when the inflammation had gone down but the tendons were still super tight -- sit on the floor with your legs stretched out in front of you, toes pointed towards the ceiling. Wrap the rope around the ball of one foot, and hold the rope about midway between your knee and your foot. Gradually pull on one side, so the sole of your foot turns towards that side (toes still pointed to the ceiling). Continue until you feel a stretch, hold and release. Do both sides on both feet.

You might also consider insoles like superfeet in your cycling shoes.