What's wrong with your calves? Do they tighten up on you after running? Any shin splints? You don't need larger calf muscles to increase running endurance, just look at most world class runners bodies and you can see they are lean.
Try more water and potassium before a workout and immediately following. For your push ups , remember to keep your core section (your abs and glutes) held tightly together as much as possible. Allowing yourself to flex or loosen up while performing a push up doesn't allow you to maximize the bodies muscles in a group effort to accomplish work.
Don't flare your arms out like you see people do. Keep them tucked in like chicken wings, and you can engage your triceps, lats, and upper delts. If your arms get out from you, it becomes a solo show for your pecs and small part of your biceps.
On your descent, pull your shoulder blades back as far as you can, this will push your chest down to its maxium range, thus giving you the shortest distance to travel to complete more in a set time period.
Other bad things people to hinder thier push ups are leaning to far forward when pushing or descending. Or placing the hands too far out or inversely too close under themselves.
"Kid, I've sat on the department ****ter longer than you've been a cop." (CatDoc to Chevy SS, the single greatest post ever on RP!)
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