25 year old male, been running for 4 1/2 years, been training seriously for about 3 years, personal bests are 18:26 in the 5k, 29:29 in the 8k, and 1:21:59 in the half marathon. Currently training for a half in may where I hope to get around 1:20 but also want to get faster in all 3 distances. Never ran in school and only self coached. I’ve come a long way but hope to get better and hope to win a race one day. I’ve built my way up to 60-70 miles per week doing about 9-10 miles per day in single runs with the easy runs, intervals once or twice and tempos and long runs every once in a while with a day off every 6 or 7 days but a lot of the time my leg muscles are beat even though I’m running extra slow some days. I take that as a sign as I’m overtraining. So id like to know what would be a good training plan to get to my true potential. Or do you think I’m close to my ceiling already? I really appreciate the responses.