January 03, 2012

Lactate threshold runs

On Sunday, as I lounged on the couch recovering from my long run the day before officially beginning my 18-week program in preparation for the Vancouver marathon, I thought it worthwhile to re-read the advice on why and how to do each of the sessions with the benefit of having followed the training structure for three months late last year.

My training is similar to what I did for my most recent marathon(s), except that I am starting my Advanced Marathoning program six weeks earlier by following an 18-week version and it's the next size up with a higher weekly volume (113-137km, from 88-113km).

This first week is as follows:
Mon recovery 8km
Tues lactate threshold 14km incl 6km at half-marathon race pace
Wed medium-long run 19km
Thur recovery 10km
Fri general aerobic 16km
Sat recovery 10km
Sun long run 27km

Details can make all the difference in preparing for and executing a training session. So I revisited the explanations on each type of session, and decided what that meant in terms of pacing this time around;  2011 was my best running year hands down, in which I improved my marathon PR from 2008 by 64 seconds.

While I didn't improve my 10km and half marathon PBs, also from 2008, I believe I am starting 2012 in my best shape ever and am aiming to up the ante in my training by targetting a faster half-marathon and marathon goal race pace. (Of course the key is being able to achieve those goals, but the first step is feeling confident enough to commit to trying.)

This time I am planning to use a heart rate monitor, particularly in the sessions at half-marathon and marathon race pace, and the long runs. Nearly all my training from 2001 until 2005, mainly as a triathlete, was done based on heart rate, which taught me a lot about pacing and what different levels of effort, as defined by the target heart-rate zones, usually 4 or 5, feel like in beats per minute.

As my next coach didn't focus on heart rate, I haven't paid attention to it since then. One important reason for me to start using it now is Mr Garmin. Since using it, I've found myself getting stressed and/or annoyed when Mr Garmin's assessment of my pace didn't correspond to what I thought it was and/or the level of effort I felt I was putting in.

Sometimes it was simply the weather or my surrounds that made Mr Garmin less reliable, other times it was my own tiredness from training that caused my pace to fall short. Using heart rate is an excellent way to help guide and gauge your sessions. Since Mr Garmin is measuring distance, pace, etc, already, I've decided to add my beats per minute to the mix.

Today's session was a lactate threshold run, defined in Advanced Marathoning as " tempo runs in which you run for at least 20 minutes at your lactate-threshold pace. This corresponds closely with your current 15K to half marathon race pace. For most marathoners, this pace range corresponds with about 82 to 91 percent of maximal heart rate."

I dug up some facts from the past. On July 11, 2001, I had a lactate threshold transition test done in Sydney, Australia. I ran on a treadmill set at a 1 percent gradient. Temperature was 20 degrees Celsius. My lactate threshold point then was measured at 13.0 kph, my heart rate at 170, while my anaerobic threshold point was measured at 14.6 kph, with my HR there at 170. My max heart rate was measured at 184 while I ran, briefly, at 18.0 kph.

That was, of course, 10 years ago.

Another measurement was from the 2003 Gold Coast Marathon, during which I lowered my PB for the distance from 4:11 to 3:24, my average heart rate was 168, according to my notes from that race.

Your heart rate (including the max) drops with age. On the flipside, as you get fitter (and there's no doubt I am much fitter now than in July 2001), you can longer sustain running at a higher heart rate.

Based on my max heart rate as measured in 2001, my heart rate should stay between about 150 to 167 during lactate threshold runs. Confirming that those are the right numbers for me indeed, is a matter of recording my heart rate in training (though, of course, I could also get another test done). 

After warming up for 5km, I had a 6km effort at half marathon race pace, followed by a 3km cooldown.

I made sure to ease into the speedy part as it's early in the season (another reminder I picked up from re-reading advice on the training); I felt good throughout, and was pleased with 25:13:30, an average of 4:12/km (or a 88:48 half marathon), for the 6km effort. My average heart rate was 162, acccording to Mr Garmin. Seems that zone still works pretty well.

A few more notes on lactate threshold training:

In Alberto Salazar's Guide to Road Racing, Salazar says "... the bottom line is that you can train your body to be more efficient in its use of lactic acid [or lactate]. This shifts the lactic acid threshold to higher speeds - preparing you to race that much more quickly. Because this shift in lactic acid threshold is a separate effect from changes in VO2max or improvements in running efficiency, it gives you a third variable on which to target your training."

In The Competitive Runner's Handbook, Bob Glover and Shelly-lynn Florence Glover say, "Lactate threshold training is primarily at a pace slightly slower than 10K race pace (15K to half marathon pace). Tempo runs are the most effective way to improve lactate threshold. These workouts are particularly important for half-marathon and marathon training, but still valuable for 5Ks and 10Ks."

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