There is a word «разбежка» - break off (mainly in aviation). May be you saw the combination this word with preposition «при». For example: При разбежке самолёт набрал скорость взлёта – During break off the plan had got take-off speed. And yet it is in sport: jumping, triple jumping etc. I’ve noted your question first accidently. I am sure you will get a lot of answers, cowboy! Good luck!

It also could mean "scattering" like e.g. in paint-ball, where players scatter to their positions. In aviation, it is "take-off roll". In sports and everyday life, "разбег" (running start) is used.

разбежка = разбег - speeding up, running start прыжок с разбегу - running jump прыжок без разбега - standing jump Здесь нет места для разбега - There is no room to take one's run.

Thank you Andrey. This helps me understand the word in more than one usage. The cowboy comment was funny :) I guess it would be "cowgirl" since I'm female. :)

Thank you for your answer. Yes. I think it is like "При разбеге" as it is talking about sports when you would be running at the same time as doing something else. Спасибо. :)