Sore Quads - Lower Inside

Morning Men & Women!!!

3/4 of the way through a training cycle which will end with IMNC 70.3 in October. This cycle has many bricks, which I have been able to accomplish well without any lasting fatigue or pain during the run. Longest was 48 miles + 4 miles off the bike.

I have now run 3 Olympic Distance events, two last year and one this year. In each event the inside quad muscle above knee gets cramped and stays sore during the race. Usually this is immediate, this time it took about 3 miles for that effect to kick in. It is also then sore for a couple of days after.

My quick readings say that perhaps I have been overusing my quads on the bike and need to improve core strength to keep more muscles engaged?

An example of my last two bricks
43 miles at 19.8mph, 4 miles 8:20
48 miles 17 18.9mph (hillier course), 4 miles 8:20

This weeks splits:
27 miles at 18.4mps (tough hills), 6.2 miles 8:40 (on trails)

I feel well trained, specifically for the Olympic and feel good about the upcoming 70.3 but this quad pain has me confused.

This morning I started a daily core routine...hahaha