I get that. RPE (effort level) is a good thing to focus on if a little unsure about pacing. The longer the rep, the slightly lower you want the effort level to be . It’s a tricky one though. For yourself, someone who runs 5k in about 28 mins, it’s not as important to slow the pace down. As 30 mins around 5k pace is close to 5k pace for you. But we also have runners who do 5k in less than 20 mins. So if they were to run the whole 30 mins at 5k pace they end up doing 7,5km at 5k pace which is too much for them and would increase the risk of injury. So the pacing is probably more important for them to get right than yourself (does that make sense?). If not ask or feel free to ignore me. But looking at your Strava the pace was good. So well done Philippa.