[quote]Mike,what would you recommend doing for the post chain when i do these?
RDLs and similar lower body pulling movements aimed at strengthening the posterior chain.
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I will push back a bit more here. I think front squats are a pretty crappy exercise for sprinters especially if you're trying to push a front squat max. Big waste of energy I have found. Sprinting is a back dominant activity. Front squats are a front dominant activity. I might consider something like Barto mentioned though.
Front squats are great for your core but no more so than something like a snatch, jerk, or an overhead squat.