Les:
I've seen this comment soooooooo many times. Now, I am Lydiardite so everything I say would be around Lydiardism. Many people say Lydiardism doesn't work because they stay at Lydiard's "marathon conditioning" and never advance to hill training, repetitions, time trials and sharpening phase. You're supposed to build up by running a lot for 2 to 3 months (not 3 years); then you work on resistance/plyometrics (strength training as well as suppling) then sharpen with lots of interval type work. Then on the top of that, you time trial (continuous effort without a break) as well as sprint work to maximize your top speed. Unless you do ALL that, it's nothing but a cake half cooked.
Now you have finally started to "balance your program" with those other elements of training, yes, your times will come down--probably quite dramatically. But I will predict, if you jump to conclusion that less running and gym work are the key to improving performance and omit foundation building in the next couple of seasons, rest assured, he will hit the wall and run out of gas. You MAY get lucky and improvement lasts a year or two or even three but you will never fulfill what you truly could have done without foundation work.
This is the biggest problem in this country when young 16, 17, 18 years old thinking this way, cut short on foundation aerobic work and they hit the peak in 2 or 3 years before they even reach 20 years old. And we all wonder why we never hear those high school wonders any more.