"I read your comment about "feeling" the run and have heard you say this in the past. I'm sort of caught between running a strict training "plan" w/a set pace and distance v. running time and feeling the pace. In truth, a faster pace feels good even on long runs. I know the goal is not to get hurt but I also enjoy the challenge of a strong run whether it is a short or long distance. Any suggestions?"
Training Plans and Weather Prediction
To answer Scott's question, when I'm describing feeling the run I'm talking about listening to how your body is reacting to the run in that moment and adjusting the planned run to facilitate the most efficient use of training time. Think of a training plan like a weather forecast, but without doppler radar, and the internet... those tools are generally reserved for the college and pro athletes. Based on today's weather you can come close to predicting most of tomorrow's weather, and maybe the day after that, but any further and it's a shot in the dark. When you're predicting tomorrow's weather you have to take specific measurements today, total change in barometric pressure, cloud cover, wind direction, wind speed, etc., the more analysis the more accurate the prediction, but when tomorrow arrives it's still important to re-check the variables, see where they line-up with the prediction and make adjusts accordingly. Weather analysis is the same concept that I'm talking about when I say you need to feel the run.
Feeling The Run
The day before a training run it's important to take note of specifics: stress levels, energy levels, fatigue, sleep hours, diet, etc., again, the more identified variables the more accurate the prediction and then based on everything you've just identified you can make some predictions about what type of run you should do tomorrow. When you're about to go on the run the next day, however, go over the check list and see if everything is still in-line with the predictions you made the day before. If you feel really fatigued, and on your schedule you have a speed workout planned, it may be a better option to push that day back one more day and take an easy day. This will give your body full use of itself before tackling a workout that demands everything you've got. Maybe you're feeling really recovered and full of energy, bumping up your long run may be a good idea, especially if it fits better into your schedule.
While you're on the run it's even more important to go through some kind of check list to make sure most things are adding up to a positive training effect. How do my legs feel? Am I breathing harder than usual? Can I concentrate as well as I'm used to? If something doesn't feel right, it probably isn't and it's better to be under-trained than over-trained. Ending the workout early will save frustration through-out the training season and most likely eliminate the risk of injury. The more you record your data (training log) the better you'll be able to pick out indicators of something going really well or something going horribly wrong.
Strict Training Schedule vs Customizable Training Schedule?
If you just stick to the strict schedule and ignore how things are reacting in terms of your own physiology, well, you may survive, but the odds are much higher that you're not going to be as fit as you may have been. It's all a balance of historical data, real-world data, and educated guesses. So, it is important to set out some type of schedule, but adhering to it because it's on paper and ignoring how you feel isn't going to produce the results you want. On the same note, if a training plan is dictated by pace and distance it doesn't take into account terrain or the differences in rates of adaptation. *There are a lot of assumptions being made in the following example, the example is to point out concepts, not hard fact. Don't over analyze it, please.
If three people are following the same plan, and they're at the same fitness level and Day One of the plan calls for a 6 mile run at 5:00 min./mi. pace; one runner(A) lives at the beach, one runner(B) lives in foothills, and one runner(C) lives in the mountains. Again, we've already decided that all three runners are at the exact same fitness level. So, they all go out for their run, (A) finishes in 0:30:00 with an average heart rate of 160 bpm, (B) finishes in 0:35:00 with an average heart rate of 170 bpm, and (C) finishes in 0:45:00 with an average heart rate of 180 bpm. Day Two of plan calls for a 10 mile run at 7:00 min./mi. pace. (A) finishes in 1:08:00 avg. heart rate of 155 bpm, (B) finishes in 1:15:00 with an avg. heart rate of 162 bpm, and (C) finishes in 1:45:00 with an avg. heart rate of 178 bpm. Day Three of the plan calls for a 12 mile tempo run. (A) is the only runner that can hit the time, (B) injuries his Achilles tendon, and (C) stops halfway due to exhaustion. Why? They all had the same training plan, right? By Day Three (A) has run 1:38:00 with an avg. heart rate of 157.5 bpm, (B) has run 1:50:00 with an avg. heart rate of 166 bpm, (C) has run 2:30:00 with an avg. heart rate of 179 bpm. From a sheer time stand point there's a noticeable difference, and from a heart rate standpoint (very accurate measure of intensity) another noticeable difference. When the training plan changes to time and feel (intensity) all the runners run different times, but their average heart rates (intensity) will be very close. Doesn't mean they're going to react the same to the training, but that's where training is a gray area not black and white. What works for me, may not work for you, even though we both run a 1:15:00 half-marathon.
Now, what if each runner is training on the exact same course? The main difference is going how each runner is reacting to the training plan. If (A) is adapting well and has only moderate amounts of fatigue post-run, no soreness, and injuries are obsolete, than the training plan is working well. If (B) is too tired to complete most of the workouts after the first two weeks, than it's a good indication that the training load is too much or not the right pattern of training stress. If (C) feels the same amount of fatigue as (A), but is getting injuries every other run than the training load isn't patterned correctly or the load is too much. The key is to take notes, and make the right call pre-run and during the run (feel the run) to ensure things are matching up.
Fast, Slow, or Slower Runs Throughout the Week
As far as balancing the types of runs, a good general rule of thumb that I follow: Each week set out two to three quality runs, again the numbers depend on how you're reacting to training, one or two runs make-up 20% to 35% of your total weekly time/mileage, and one fast paced. As far as the intensity here's a good break-down of weekly training intensity: 60 - 30 - 10. 60% of your weekly running is done at a low intensity (your goal is to work on form) 30% is at a moderate intensity (long runs to help induce fatigue) and 10% at a high intensity (applying your learned form at a faster pace.)
Hopefully this helps, hopefully it sparks more questions, and hopefully you enjoyed it.