The first time I got HIIT

I mentioned a couple of articles ago the inclusion of the Tabata Protocol in my workout.  Today was the first time I tried it.

The basic principle is that you do 4 minutes of very hard work and it's somehow equivalent to an hour of cardio.  While initially somewhat sceptical, I found it hard to turn down such a huge potential improvement in training efficiency.  If I can do this in four minutes (eleven once you include warm-up and cool-down), then that leaves a lot of time afterwards for weights and strength training.

There's indeed a compression effect going on : 1 hour of pain in 4 minutes of time.  Efficiency has downsides.

I downloaded a little gadgety Tabata timer for my Samsung (the most gym-unfriendly phone on the planet) and got on a stationary bike.  I also wore my heart rate monitor, the very imperfect results of which are below.

Results


I know - that doesn't tell you very much.  I'll get into that in a minute.

So the way it works is you do a 4 or 5 minute warm-up without straining yourself, then you set off the timer and for 20 seconds, you go hell-for-leather, pedalling as hard and fast as you can against a resistance that means you have to make an effort to get the pedals to go around.  Then you rest for exactly 10 seconds.  Then you do another 20 seconds of crazy effort - eight repetitions of effort in total.  Then you cool down for a couple of minutes of easy pedalling.

Conclusions?  Well it hurts.  Obviously.  My heart rate spiked quite violently and after the third or fourth repetition you can feel the lactic acid building up in your thighs.  The 10 seconds rest really aren't sufficient to get your heart rate down any significant amount before you have to get going again, and for a measly four minutes exercise, it's far more tiring than it has any right to be.

Afterwards, I found that all the weight training exercises I did felt as though they were being done on tired muscles.  Clearly the protocol has an effect on the entire metabolism.

Garmin Forefunner 210 Fail

This is annoying.  My Garmin HRM is basically useless for interval training.  You can see the heart rate graph below

The long straight lines had me confused, so I fiddled and hacked and found a way to get the raw information from the HRM into a spreadsheet, and what I found was a table that looks like this.

Total Time	Time	Heart Rate	Sample Gap
613.35	10:24:01	124	00:00:00
613.35	10:24:02	123	00:00:01
613.35	10:24:23	128	00:00:21
613.35	10:24:40	133	00:00:17
613.35	10:24:52	128	00:00:12
613.35	10:25:31	133	00:00:39
613.35	10:25:47	128	00:00:16
613.35	10:27:39	133	00:01:52
613.35	10:28:02	128	00:00:23
613.35	10:28:19	133	00:00:17
613.35	10:28:30	138	00:00:11
613.35	10:28:55	143	00:00:25
613.35	10:29:07	148	00:00:12
613.35	10:29:16	153	00:00:09
613.35	10:29:21	158	00:00:05
613.35	10:29:27	163	00:00:06
613.35	10:29:43	158	00:00:16
613.35	10:30:20	163	00:00:37
613.35	10:30:27	168	00:00:07
613.35	10:30:45	163	00:00:18
613.35	10:33:03	168	00:02:18
613.35	10:34:13	162	00:01:10
613.35	10:34:14	162	00:00:01

 

So what we have here is a total of 23 readings over a 10-minute period, for an average sample rate of one heart rate reading every 26.7 seconds.  The first four minutes are warm-up, so the real data starts at 10:28:02.  I have no idea how my heart rate went up or down during the work and rest phases.  There are gaps of up to 2:18 between the samples.  The data's almost useless except for the fact that I know my heart rate went up to 168, so I made a decent effort.

 

Next time, I'm going to leave the Samsung in the changing room and use the Garmin's internal interval timer to time the laps.  Downside : no music.  Upside : perhaps it'll measure the heart rate correctly.