Discover the Fountain of Youth

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Decreasing-time workouts are your key

Over the past 25 years, I have experimented with decreasing time workouts, and now believe they are …

Illustration by Kevin Howdeshell

Over the past 25 years, I have experimented with decreasing time workouts, and now believe they are a runner’s Fountain of Youth. In these workouts, the pace increases throughout the run, and since there is no rest period, they may be the toughest workout a master can do—but offer the greatest reward.

Previously, I only recommended them for the young guns but, after working with numerous masters, found that decreasing-time workouts are beneficial for all ages. However, you should be a seasoned master trail runner and/or have a well-developed base before adding decreasing-time workouts to your schedule.

So Simple a Trail Runner Can Do It

The concept is simple—repeat intervals, up to five times, running each one faster than the previous. You will learn pacing, how to push mentally and physically harder as you fatigue and to run negative splits (the ability to run the second half of your workout or race faster than the first half).

Starting Out

Pick a loop of one-half mile to three miles, depending on the length of the race or run you are training for (see below).

Interval Distance Race Distance
Half mile 5K to 10K
One mile 10K to 10 miles
Two miles 10 to 15 miles
Three miles 15 to 100 miles

This workout is taxing, so tackle it when you are well rested.

For this example, I’ll use interval pacing for a 40-something-year-old master running a two-mile loop. In the first session, do three repeats. Run the first loop conservatively, i.e. add 30 seconds to your average running pace. If you usually run a mile in 8 minutes, run the first loop at 8:30 pace or 17 minutes. For our 40-something runner, loop two should be 15 seconds faster, i.e. 16:45, and loop three should be 16:30. Though running still slower than your normal pace, you will have increased your effort as the workout progressed.

A Sliding Scale

See chart below for scaling the interval time reduction per repeat (in seconds) based upon age

Age 40-49 50-59 60 and over
Interval Distance
Half mile 7 5 2
One mile 10 7 5
Two miles 15 10 7
Three miles 20 15 10

Upping the Ante

Providing the three-loop workout went well (see caveat below), on the next decreasing-time workout, our 40-something runner would add another loop, again increasing the pace by another 15 seconds (16:15). The next week, he could add a fifth loop, shooting for 16 minutes, for a total of 10 miles.

Now for the caveat. No matter how fast you run a particular loop, each ensuing loop must be 15 seconds faster than the previous. For example, even if you run a loop 25 seconds faster than the previous one, say from 17:00 to 16:35, your next loop should be 16:20—15 seconds faster. If you can’t run 15 seconds faster, the workout is over. Try again another day. You are either too tired or you ran a previous loop too fast. The benefit is considerably less if you run the next two-mile loop only five seconds faster. Adhering to the time reduction forces you to push harder and increase the pace as you tire, simulating end-of-race fatigue, training you to fight “through the wall.”

Pick Up the Pace

After you have worked up to five loops, the goal is to increase your pace per loop. A recent hard trail run or race indicates your potential pace for loop five. Using the example above for a 40-something, if your comfortable pace is 8 minutes per mile, but your race pace is 7 minutes per mile, on a two-mile loop, your ultimate pace goal should be loops of 15:00, 14:45, 14:30, 14:15 and 14:00.


Over time, you should notice that your pace on the first loop may become inexplicably faster, which means the negative time workouts are working their magic.

Adjust the time reduction based on your age, fitness level and repeat distance. Although you could do this workout every week, be conservative and do it every other week, adding them to your training about eight to 10 weeks before a key race or run.

You will think you have found the Holy Grail of trail running. You will be able to pace yourself and to run negative splits. You will have untold energy as you near the end of a race. And, once again, you will have recovered some of that lost youth.

A Case Study

When I worked as a trainer in Houston, Texas, on Wednesday nights, we ran decreasing-time workouts on a three-mile loop in a park. Loop one was 21 minutes (7 minutes-per-mile pace). Loop two was 20 minutes, loop three 19 and loop four 18. If you had energy in the tank, loop five was sub-18 minutes.

That summer, as an early 40s master with my much younger partner, we did the four-day Border to Border Triathlon team race in Minnesota. Day three was a 50-mile run where the two team members alternate running. we chose one-mile intervals. Completing the 50 miles in 5 hours 13 minutes, we averaged 6:15 minute miles—which we attributed to our training with decreasing-time intervals.

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