On Sunday, my legs felt tight and sore, but I decided to do my long run anyway.

I did the long run, but it was painfully slow.

As you can see, some of my miles were close to and over 10:00 per mile. But here’s the good news. That remarkably slow long run really helped me recover from the previous day’s tempo run. This morning after the previous day’s long slow run, I felt like my legs had a session in a hyperbarbic chamber; they experienced very little strain and all the oxygen they needed for over 90 minutes.

Many distance coaches and trainers argue that this is one of the primary roles of the long slow run. In addition to all the other cardiovascular, circulatory and endurance benefits, getting oxygen rich blood out to muscles in need of repair is crucial.

My plan this summer, in addition to regular mileage during the week, is to continue with a tempo run on Saturday followed by a long slow distance run on Sunday.

Also, I’m going to continue to plenty of Active Isolated Stretching. I have Jim Wharton’s “Stretch Book,” and I’d recommend it to anyone.

That said, it is very hard to cultivate aerobic fitness unless some other key ingredients are not being added at the same time. Heavy volume without good form leads to injury. With the occasional session of 8 to 10 x 60-100 meter strides, the body learns what to do in order to run most efficiently.

Once a runner achieves a reasonable level of aerobic fitness and solid running form, the next stages of competitive development fall into place much more easily. Sessions at maximum heart rate or aerobic threshold become more effective and are less likely to lead to injury or burnout.

For beginning competitive runners in high school or at the middle school level, attaining a solid level of fitness is often the greatest obstacle. It takes time to get fit and track and cross country seasons just aren’t long enough. It’s extremely important to train in the off-season!

Here’s an excellent article about different types of fitness.