how much speedwork do you do? what kinds of speedwork?
Where do I find a trainning schedule for a 50 year old.
It is more about finding a trainning schedule for your level of ability. Also how many days a week do you run? What is your total mileage? It is all about knowing what your body can handle without causing overtraining.
Also does your body ever get some rest? If you are running 5k's all the time you may not have the time to recover if you implement a more demanding training program.
When I raced 5k's (competitvely) I introduced a number of speed workouts. I would put in two a week, along with two easy runs (short to medium mileage), one long run, and usually a tempo run or moderate pace run.
example(s):
repeat 800's (6 x 800 at a little more than race pace)
repeat miles (4 x 1 mile on a track at a little faster than race pace, rest (jog) 3 - 5 min)
Fartlek workouts (on grass, if possible) (2 sets of 8 x 60 sec sprint, with 90 sec rest in between, and 5 min rest between sets)
Ladder workouts 200, 400, 800, 1200, 1 mile and back down (at race pace, rest the distance you ran)
Repeat Hills (approx 400m - 800m in distance, this being the last 200m being uphill, a moderate incline, rest going back to start)
ect..,
All these examples are based on my training (I am no expert), but if you implement them into your training program and adjust them accordingly you could see improvements in your time.
The main thing is do the workouts that respond best to your body. If the hills hurt the knees, back, ect. then do the repeats on the track. Also work at a pace comfortable for you, overtraining leads to injuries. Every fourth week should be rest and recovery (low/slow mileage).
If you have a friend to run with it is always better, keeps you honest.
Hope this helps
Good luck