early paced dogs ie sprinters and short distance ones do not take in the any where near the air they need for the first half the race

where as longer distance ones start off (genearlly) slower than the sprinters building up the air as they travel

so the sprinter tpyes dont have the reserve to go longer disatance

its down to the mussel make up while built the same the mussel acts slightly differant in each type

if you take two dogs one sprinter one longer distance type and run them over the sprint the sprinter will win and the other wont even be pantting

now take the same dogs push it to 525 yards the sprinter will be stressed and again the stayer will be fine but if you push the distance out to say 600 yards or more the sprinter will fall back and back while the stayer will get stronger and stronger

hope you see where i am coming from ill try to find an online paper on it tonight for you

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