Everyone has seen this runner: They toe the line at the local 5,000-meter race, go out at 6:30 pace for the first mile, subsequently slowing down to 7:30 pace on the third one. When you approach their gasping form as they hang onto a signpost, they tell you, 'I could have raced this one, but this was only a tempo run.'
When I coached weekly workouts it was my "job" to provide training which worked as many energy systems as possible.
(ED. COMMENT: My coach reminded me we used to do tempo runs as part of the group's training, for which he is correct...a few things changed some over the course of a few years...sometimes change does not always move toward the more beneficial.)
One day a week we did a lot of aerobic-to-threshold-pace stuff at a short (one-to-two-minute) duration. The second workout of the week consisted of efforts lasting anywhere from two-to-five minutes. Several members of the training group liked the longer repeats a great deal. But it was difficult to encourage tempo running as a solo workout outside of training sessions.
I didn't run regular tempo workouts, either. Yes, there were the occasional "anti-social" Wednesday evening beach runs, where I'd go out at a low-seven-minute pace for as long as my lungs could stand, then push a little harder for the last three miles. But it wasn't until I became treadmill-bound and more-closely focused on my own training I started to look a little more closely at the tempo run.
Most recreational runners don't like tempo running; I'm not certain if it is because they don't know what pace to run, they think tempo runs are too painful, or they'd much rather socialize during their runs. But I can tell you they're missing out on some free speed at a low (time) cost-to-(speed) benefit ratio.
First, let's look at what constitutes a tempo run. Dr. Jack Daniels, in "Running Formula," says that (ideally) twenty (to-thirty) minutes of steady running at threshold pace is a tempo run. That's twenty minutes of steady running at an effort level where our body uses the lactate as fast as it is produced from carbohydrate metabolism during physical exercise.
For example, a person who runs a 21-minute 5,000-meters would - according to Daniels - run tempo runs at about 7:10/mile pace (for those who speak treadmill, that's about 8.4 mph). If you still don't have a copy of "Running Formula," never fear. Take your 5,000-meter race pace per mile and add 25-30 seconds.
Are tempo runs painful? I will say they are no easy, breezy walk in the park. After running my first tempo run in about a year - and my first tempo run on a treadmill - my average heart rate was about five beats higher across the board, and my max heart rate near the end was just shy of 85 percent of maximum. For those runners who prefer to not inflict twenty minutes of "comfortably hard" effort on themselves, Daniels recommends what he calls "cruise intervals" of one-mile or ten-minutes, broken up with 30-to-60-seconds of recovery.
Another challenge of tempo running comes from having the right course. The right circuit or course can make all the difference. If your favorite training stretch - for example, from the hotel where Suzanne and I like to stay to Audubon Park and back - has a lot of intersections and traffic, it's easier for me to run "cruise intervals." A good, lightly-trafficked and distance-marked loop or bike path, like the 4.25-mile or 5.8-mile loops on Pensacola Beach, are good for tempo work. Levees and rails-to-trails are also good.
And it doesn't necessarily have to be a solitary affair. Social runners who are at or near the same ability level can work together and ensure the run tempo does not slack off.
Tempo work is probably one of the most under-appreciated, and under-used, workouts which are available to the self-coached runner. The only things necessary for longer-distance speed gains are to know the proper pace, set aside twenty quality minutes, and keep pushing the entire piece.