Marathon pace test

Last night was another of my pace tests. To recap, this originally developed from an idea that a marathon is run at the maximum pace you can sustain for at least 10 miles without any cardiac drift. If your heart rate is rising at the end of the run, then you aren't going to be able to sustain that pace for a full marathon. You're looking for your maximum steady state pace. This doesn't guarantee your endurance is good for the 26.2 miles, but at least it gives you an idea of the heart rate to run at given proper endurance training. If you were to factor endurance in, you would want to be able to run 16 miles at least without any drift, but there's no way I'm going to be running 16 miles at marathon pace in training!

Of course, to do this test you have to have constant conditions, so it's best to do it as circuits to avoid varing terrain, gradient and weather (wind).

From marathon experience I now know that my marathon HR is 145bpm. The test then becomes more a question of what pace can I sustain at 145bpm, rather than what heart rate I should be running at.

A caveat on cardiac drift. It's not just lactate that causes it - temperature and dehydation can affect it. In the winter I don't tend to overheat, so I find I get up to mara HR fairly quickly and then hold it there. In the summer I spend the first few laps getting hotter and hotter so it takes a while before I hit a steady state and my HR stops rising. The pace is also likely to be lower due to the effects of heat - blood being used for cooling and not powering the muscles.

With me so far?

Here's the results of last night's run: a 1 mile warmup and then 5 2415m laps running at what I felt was marathon pace.

2415m (~1.5 miles) continuous laps. 1.5 miles warm up/cool down not included

Lap	Lap time	Mins/mile	bpm	%of max HR
1	10:56	07:17	132bpm	76%
2	10:50	07:13	138bpm	80%
3	10:53	07:15	141bpm	82%
4	10:59	07:19	141bpm	82%
5	10:54	07:16	141bpm	82%

Yet again fatigue has stopped me hitting marathon HR. I've never found fatigue affects my pace/HR relationship, just my ability to hit a pace, ie lower HR. What you have to watch out for is when you do see your pace/HR affected then that is a sign of overtraining.

So from the above, I'd say my current marathon pace at 18C (it'll hopefully be cooler in Abingdon) is 7:05/mile when extrapolated up to 145bpm.

Compare this to my previous test 6 months ago

Very pleased!