Running at 5-Over

Finding Running Speed

After a summer and early fall of no racing so I could fully recover from back surgery in late June, I finally signed up to run the Las Vegas Half Marathon in mid-November. To get some idea of how I might compete, a couple weeks ago I ran a 5K time trial on the rolling, two lap course in Sugarhouse Park. Knowing that a half marathon time of around two hours would make me competitive in the 70-74 age group, I figured an initial time trial of around 9 minute miles would put me in the ballpark.

Since I had been doing no serious race training, I decided to use all the tools at my disposal to get my best time: metronome set at 90 strides/180 steps per minute; the swing-rite harness to ensure compact armswings and quick turnover; my favorite lightweight running shoes; and heart rate monitor. I conducted my normal pre race warmup routine and set off in perfect running conditions: cool, calm, and sunny.

My results were encouraging. My overall time of 27:32 was based on two evenly run laps at an 8:53/mile pace. I felt pretty strong throughout the run with no bad patches, with my stride rate in synch with the beeping of the metronome, and with a max HR in the mid 160s in the closing mile. Not bad and a good place to start refining my training strategy to prepare for the longer race.

To run faster I have to increase my stride length and/or frequency and/or reduce contact time. However, since I’ve always preached that the optimal stride frequency is 90s/180s my first inclination was to refocus on leg strength to increase stride length. But without sophisticated technical equipment, it is nearly impossible to estimate your stride length while running. Stride rate, on the other hand, can be managed by using the metronome and matching steps to beeps. Why not try a faster turnover rate? After all, I learned long ago through cycling if you “over-spin” you can backoff and quickly recover, but if you “over-grind” in too big of a gear you may not recover until the ride is over. So I decided on a simple experiment. I would repeat the time trial just five days later with the only change being running at “5-Over” the normal 90/180 cadence limits.

The results: 26:52 @ 95 beeps/minute, with nearly identical HR readings. In other words, the quicker cadence brought me home 40 seconds faster at the same levels of recorded effort. Let’s take a much closer look at what my inner geek can discover from the data.

• Time Trial #1 produced a time of 27.52 min @ 90/180 cadence – an 8:53/mi pace. Stride length was computed to have averaged 6.6 ft/stride or 3.3 ft/step from the formula (3.1 miles x 5280 ft/mi) divided by (27.56 minutes x 90 strides/minute).
• Time Trial #2 produced a time of 26.87 min @ 95/190 cadence – an 8:40/mi pace. Stride length was computed to have averaged 6.4 ft/stride or 3.2 ft/step from the formula (3.1 miles x 5280 ft/mi) divided by 26.87 minutes x 95 strides/minute).
• The performance gain from the faster turnover rate was significantly greater than the degradation of stride length of a hair over an inch per step.
• If I had been able to maintain my 6.6 ft stride length throughout Time Trial #2, my projected time would have been 26:06 – an eye opening improvement of 1:26!
• Because of the short time period between time trials, the 40 second improvement can only be attributed to my ability to run at the faster cadence, although I did struggle a bit to do so during the second lap.

Final conclusion: Based on the data generated from these two time trials, I will focus on becoming more comfortable at the faster cadence by applying a “hurry up” focus whether running, cycling, hiking, scootering, or swimming. I’ll practice “running quicker.”