Dear Coach: I have just turned 50 and want to run a sub- 3:30 marathon to qualify for Boston. My best marathon is a 3:42. I have run a 43 minute 10K. I usually train at 8:15 to 8:30 per mile pace. I start my marathons at a 7:30 pace for the first miles to build up " time in the bank," and am usually on pace until 20 or 21 miles. I always seem to hit the wall. Can you give me any tips? Bill

Dear Bill: A sub 3:30 is not out of the question, especially on a cool day on a fast course. However, you need to make a couple of changes. First, slow down your normal training pace to nine minute miles because you are most likely training too hard. Wearing a heart monitor can help with this problem. Second, I recommend that you do several Predicted Marathon Pace (PMP) workouts during marathon training, starting at three miles and building up to ten nonstop PMP miles. In your case, a 3:30 marathon is an 8:00 minutes per mile pace so you need to do your PMP between 7:50 and 7:55 minutes per mile. This cushion makes allowance for slowing down just a bit in the last few miles of the race. My personal experience as well as that of the runners I coach is that it is possible to run an evenly paced marathon or even a negative split (second half faster than the first) when you run a realistic and disciplined pace. You have gone out way too fast in your past races. That is called "hitting the wall" and my guess is that you have probably ended up walking a lot at the end.

Dear Coach: I have read Roy Benson's Precision Running books and Jack Daniels' Running Formula. There seems to be some difference between the two coaches in regard to establishing training intensities for each physiological area being developed. Daniels focuses on training pace while Benson focuses on heart rate. Please comment. John

Dear John: You cannot go wrong following the principles of Benson or Daniels. There are far more similarities than differences. Both agree that sensible training incorporates the following elements: easy recovery runs, long slow runs, anaerobic threshold training, economy (400 repeats), and peaking. I prefer Benson's heart rate approach because it takes the guesswork out of training. Daniels' approach is great for veteran runners who know their current pace and know how that pace translates to various training paces. However, Daniels' advice does not help those who are relatively new to running or those returning from injury. A heart monitor is particularly useful when running an unfamiliar course because I do not have to be concerned about my pace. I simply run by heart rate, knowing that I am training appropriately. A heart monitor is also great for those who have never done speed work or don't know how to do it. You can do an anaerobic threshold run without knowing your race pace just by running at 80 to 85 percent of your maximum heart rate. Also, there many type A runners who will overtrain unless they wear a heart monitor which beeps to remind them to slow down.

Coach Kirt West is a private coach for motivated adult runners. Questions for him can be sent to him at kirtwest@erols.com