How to run a 4-minute time trial

November 15, 2017  ●  2-minute read

Over the past week, I’ve run two four-minute time trials. I botched the first one by starting way too fast. The splits of the second trial were much more consistent. To get reliable results, I recommend the following:

  • Use an 8x 30-second format;
  • Set interval alarms for each 30″;
  • Start “slowly” (think 90%);
  • Increase the speed with each 30-second segment; and
  • Keep track of the intervals so that you can go all-out in the last 30 seconds.

Round One

This week, I’ve been trying to do an uphill four-minute time trial. I need the time trial as a baseline for some speed training.

I’d never done a four-minute time trial before, so I botched my first attempt. I started way too fast. I had to stop for a couple seconds midway through. My pace for the last minute was two-thirds that of the first.

Afterward, I could taste blood. My peak lactate was 12 mM. For several days, I had a cough that made me sound like I had tuberculosis (aka. “effort lung”).

That was the “smart like tractor” approach. I’m embarrassed to admit, it’s not the first time I’ve tried that technique.

The Smart-Like-Tractor Results

MINUTE m/min
1st 184
2nd 150
3rd 124
4th 122
Average 145

Round Two

I took it easy for a few days and then tried again today. Rather than use four one-minute interval alarms, I used eight 30-second alarms. I planned to start out “easy”, speed up after each alarm, and then sprint for the finish.

That worked much better.

The Smarter-Than-Tractor Results

MINUTE m/min
1st 128
2nd 137
3rd 139
4th 165
Average 142

The results are interesting. My ending pace in the last 30 seconds of the second trial was only slightly slower than my starting pace in the first 30 seconds of the first trial: 174 m/min versus 180 m/min. That’s only a 3% difference.

And I didn’t taste blood. And I don’t have any symptoms of exercise-induced tuberculosis.

Today had several lessons:

  • It’s possible to get the same average speed by starting “slow” and going faster with each segment. It’s also less effort and less training stress.
  • The trick is knowing what that first “slow” speed is and how much to increase it each time. (I started the first interval imagining 90%.*)
  • As I increased the speed of each interval, there were a couple times where I could feel the acidosis in my legs. The feeling was slight, and it felt manageable. It made me wonder: How long is it possible to maintain a slight feeling of acidosis without slowing down? What intensity would keep the acidosis feeling “slight”? (I’ve never done much speed training, so this is new territory for me.)
  • If I only have one shot at a 30-second near-maximal burst, where would I rather spend it? At the beginning of a sprint event or at the end? When my competitors are fresh or when they’re tired?

(* Thanks to Scott Johnston for the recommendation of 90%.)

Posted in: endurance training