The phrase "a long rep" is correct and usable in written English.
It can be used in contexts related to fitness, sales, or any situation where "rep" refers to a repetition of an exercise or a representation of something, and "long" describes the duration or extent of that repetition.
Example: "After completing a long rep of squats, I felt the burn in my legs."
Alternatives: "an extended repetition" or "a lengthy representation".
Edwards had been a long-time rep for Richard Desmond's Express Newspapers, publisher of the Daily and Sunday Express, until earlier this year.
Luxury car manufacturers have a long and distinctive rep for gratuitously slipping in a bit of sex among the otherwise shiny, but boring, business of selling cars.
"The Messenger app was removed from the appstore [sic] as it has not been updated in quite a long time," a Yahoo rep noted in a Yahoo Answers forum in response to a question about the app disappearing from the iTunes App Store.
That was very well received and ran quite a long time at Circle Rep, so as Angels was ending my directing was just starting to take off.
(I know, not an easy task to find someone like that). And if you see a long line of sales reps outside his office; run, even if you know him really well.
A desultory period as a journalist working for trade papers – Gas World, Nursery World and the Miller – was followed in 1948 by entry into the theatre as assistant stage manager on a 48-week tour of No Room at the Inn, and by a long, productive period as a rep actor.
Conventional loans are tougher on things like debt ratios (comparing monthly income to mortgage payments and recurring debts), but every FHA mortgage consumer should have their mortgage rep take a long and hard look at whether a conventional loan with a 3% down payment or a 620 credit score is a viable option.
The decision to toss out the standard college rejection letter in favor of this decidedly more personal and intimate approach was a "long time coming," explained the rep.
One (gi|56593923) was a long transcript from a 4-rep SINE and another (gi|56599038) a short one from a 1-rep SINE.
With her high-density rhymes in James Grieve's taut production for Paines Plough and Birmingham Rep, Jordan goes a long way to capturing the oblivion and the ecstasy, the lust and the camaraderie of the dancefloor.
