I’m in week 19 of my plan, and fighting right side posterior shin splints. It seems to pop up when I wear my speed shoes as trainers- potentially because they don’t provide a lot of shock absorption on the cement here in Florida. But I am perplexed as to why it’s ALWAYS on the right and the left is FINE.
Could it be a mechanical issue? In looking at the Garmin ground contact balance I am right at 50% r/l for most runs with some slightly off by less than a half % on either side (not always one side). I am an underpronating upper midfoot striker and I wear the hell out of the outersole of my shoes on both sides.
Any thoughts or suggestions on what I can do, besides shift some load from recovery/foundation runs to the bike?
Nearly all running-related injuries are unilateral, affecting one side of the body only. It is true that shin splints are more likely than most other injuries to manifest bilaterally in beginning runners, but what you are experiencing still isn’t at all uncommon. I recommend you minimize your use of the racing flats and, as you suggest, shift some of your running to the bike. Shin splints are typically fairly easy to curb if you don’t let them get out of hand.