If it’s true that you are a string-bean on your upper-body, do exorsizes that will work many muscle groups. The core lifts. Bench, military, inclined/declined bench, push press, pull downs ect. Until you build a core, you should not be working on specific muscle groups. Considering you use almost every muscle in your body when sprinting. If I were to attempt a squat at 400 lbs – I would need a Lot more than quadriceps and powerful hamstrings to do it – – – When I run 100m dash I will need a Lot more of my upper body than just my biceps and triceps shoulders and back… Trust me – I’ve been to pro’s practices. The very best in the sport, I’ve seen what the pros do, even they – spend the valued bulk of their time doing non-specific lifts. You’d be suprised. They endulge in deadlifts and major body push-lifts. None of the olympic lifts concentrate on one specific muscle, that’s a fact.
– Upper body mentioned 4 times, lower body mentioned 1 time. –
By the way, your lower body is not strong enough. Until you can squat well over at least 400 lbs you are not there yet. This should be first and foremost (that’s not to say don’t lift your upper-body at all). Let’s remember that you’re a runner if I am correct? So at what point (even if you are skinny up top), does your lower-body take the backseat to the Upper-body?? Professional sprinters have ungodly, freakish squat, deadlift and lower body stats in general. However, while Maurice Greene can bench a little over 300 lbs (First person witnessed), this is a common figure for guys who weigh 175. On the flipside, none of these common-guys could even come close to Greenes out of the atmosphere over 600 lbs squat.
In truth, there should never be a question of upper-body vs lower-body.
Good question, keep working hard!