I think the number one problem runners have is running too fast, too often. It is their dream of running faster in races or win prizes that motivate them to push faster than their bodies can handle. It is a good coach who recognizes that common problem and takes measures to prevent overtraining.
One measure taken is setting reasonable to training volumes for runners. And, the volumes are personalized. Joe may run well on 1 hour runs and Jack can alternate 1 and 1.5 hour runs yet still show no signs of overtraining.
Another measure taken is to limit the frequency of races. Many runners get greedy and want to race every weekend. Some runners should race once every 2 or 3 weeks in order to avoid dipping into their well of reserves! Others may be able to race every weekend, but they need to be held back from doing hard workouts between the frequent races.
Finally, a measure I use, along with the others, is to personalize the pace a runner uses in training. I do this to give a runner a reasonable idea of what they should be doing. I do realate an EFFORT to go along with a pace, and this is a key to the successful use of paces.
For example, I may tell Fred, an 18:00 5k runner, that his distance pace is 7:26 per mile or slower and that anything faster that is a hard workout pace. I may tell Laura, a 16:40 5k runner, that her distance is 6:55 or slower and that anything faster than that is a hard workout pace. Both runners now have an idea what is reasonable. They are more likely to avoid running too fast on days between their harder workouts if they know what is realistic.
I do provide flexibility within the organization of training so that runners can adjust to how they are feeling. This is another key. If Joe feels very tired, he can as slowly as he wants. If his harder workout is set for today and he is tired, I'll cancel the workout or tell him ahead of time that he can cancel it. I do ask that it be cancelled for physical rather than mental reasons. And, if it is a mental thing, such as "I have anxiety about the training paces written." then I turn it into a fartlek workout where the athlete runs for time segments instead of by pace. I'll say, "Run 8 x 2 minutes at 5k effort, jog 2 minute recovceries, during a 60 minute run. Run anywhere the appeals to you: park, trail, et cetra."
To summarize, the problems runners have typically relate to running too fast, too often, and some ways to overcome the problem are as follows:
1) set reasonable training schedules, ones that do not include workouts which are too fast, too long, or too frequent and avoid racing more often than your body can handle;
2) set reasonable training and racing paces and durations to run;
3) provide flexibility to adjust the training if fatigue or injury or illness or motivation are taking hold (giving mature athletes the freedom to make changes that are reasonable and realistic);
4) run in mentally appealing places, for they tend to ensure enjoyment of the sport; which provides satisfaction and peace of mind.
Tinman