cracks

I seem to always develope cracks next to the stringer of my board on the side where my front foot pops up. I have a sneaking suspicion it is because I am quite a heavy footed surfer...does anyone have any tips on how to repair these cracks? Or maybe tricks in which could help me to avoid this happening in the future? This has happened to two of my boards now..and it pisses me off!!! My next board will definately be a custom board, with heavy glassing 
