I've heard that for push ups you should "inhale as you lower to the floor, and exhale when you press yourself up"
Does this apply for every single rep you do, or just every couple reps. I always end up holding my breath while doing push ups for 10 or so reps, should I be following the breathing pattern above for every rep?
Yes. Every time I have seen the suggestion of that breathing pattern with pushups, with demonstration provided (such as videos), the breathing pattern is per pushup. Personally, I find that, unless I am doing very slow pushups, I am breathing more shallowly when those regular breaths since fully (as fully as you can) filling and emptying the lungs is time-consuming, and doing so rapidly can lead to hyperventilation effects.
For me, it is strictly "inhale on the way down, exhale on the way down, one breath per one rep". I cannot support this scheme with any scientific evidence, but it works great for me personally as it creates rhythm for my push ups while allowing me to get enough oxygen to avoid getting tired too soon.
