Two of my Favorite Winter Warriors!! |
This past weekend, many of my running friends headed off to
the Snowman Half Marathon that is part of the Winter Warriors series of races
here in Michigan. These are a crazy bunch of races put on in January, February,
and March, with cool names like Snowman, Ice Cube, and Mud Dogs. It is
basically a chance for a bunch of crazy runners to get out of the house and
stay motivated during the gloomy, frigid winter days. Besides being a lot of
fun, they have some truly cute bling and age group awards, and I was very
bummed to be sidelined with of all things, a tooth extraction.
Pretty cute!! |
Anyway, the cold weather racing raises lots of questions for
runners. The biggest ones are what to wear on one’s feet, which I mentioned in
my previous post on screw shoes, and what to wear on one’s body Two layers or
three? Gloves or mittens? Smartwool or Drifit or both? Balaclava or fleece
beanie, or both? There are so many choices on a given day that I am almost too
exhausted to actually run the race by the time I am dressed for it. Packing for
all the potentials is exhausting – but I digress.
One of the key questions runners might have on race day is “how
is this cold weather going to affect my race times?” I am going to put the idea
of footing aside for now. I want to just focus on the idea of the effects of
running in cold weather itself.
Before I ran in Michigan, I had never given much thought to
how cold affects running. And, having come from a place where the coldest
weather I usually had to deal with would be upper 30s maybe once or twice a
year, there was really no reason to think about it. My first race here was a 5k in about 3 degree
weather. I thought I was fairly fit, but my race time was much slower than I
anticipated. I was a little upset and could not figure out what was wrong. I
had been training well and had done several training runs faster than my race
time (and no I didn’t go out too fast).
My answer came a few weeks later when I was running with one of my new
friends, Corey, in the Playmakers group. He said to me something like, “Well
you know you can’t run as fast when the weather is that cold don’t you. It
affects your lung and your oxygen uptake.” That was news to me. I made a mental
note to look into it, but since I had no more races scheduled until warmer
weather, I did not follow up. I avoided the question the following year by
getting out of Michigan for the really cold winter months.
That brings me to this year where I have several races
planned during what is likely to be the coldest part of the winter. I decided
to look into this idea a bit further. I began by looking in some of my
running books. Most of them discussed the idea of hypothermia as a hazard but
did not really talk about race performance. In The Competitive Runner's Handbook by Glover and Glover, I did find
a mention related to race performance. They said, “The effect of cold on
performance depends on the severity of the conditions. Running in cold or
moderately cold weather (30 to 50 degrees Fahrenheit) yields fast race times ….
But excessive cold is another story. Exposure
to extreme cold reduces both the runner’s core body temperature and maximal
aerobic power, impairing performance.” They go on to say that the clothing
worn also restricts movement, which can also affect race times.
Thus I found the confirmation that my friend Corey was
correct (I didn’t doubt I would. Corey is one smart dude and a bad ass runner).
So my next thought was “Okay, well how much does it affect it?” For that I had
to turn to the Internet.
I found two really great sites that give information on
this. One is an excellent article by Matt Johnson on the web site Runner’sAcademy, that discusses the
key physiological components of the effects of cold on pace, including reduced
muscle contractions, changes in energy sources, changes in lactate production,
etc. If you are interested in understanding the physiology, the article is
definitely worth a look. The bottom line is that there is a predictable
performance decline in cold weather related to temperature, similar to that in
hot weather:
Air Temperature
|
Decrease in Performance
|
50 °
|
None
|
32 °
|
1-2%
|
20 °
|
3-4%
|
10 °
|
5-6%
|
0 °
|
8-9%
|
They give an example of a person at an 8 min/mile pace to
show the decline. The paces at the various temperatures would be 8:00, 8:07,
8:17, 8:26, and 8:41.
To figure out how this would play out for your particular
pace, you can do the math. The formula is pretty simple:
1. You need to
convert your running pace to seconds, i.e. 9:10 pace is 9 x 60 secs +10 secs =
550 seconds.
2. Next, multiply that by the proper % from the table for
the air temp at race time. For this let’s say it is 15 degrees. I will call that
between 4% and 5% so 4.5% (or .045 as a decimal) 550 x .045 = 24.75 sec
decrease. Let’s round it to 25 seconds.
3. Add that back to your pace per mile: 9:10 + :25 =
9:35. So for this example, someone who
would normally run a 9:10 pace could expect to run about a 9:35 pace in 15
degree weather.
If you are wondering how this would play out at other paces
and are not a math whiz, I found another page with a really nice table of temperature
and running performance. To take a look, click here.
If you look at this table, you will see that the performance
declines from 50 to 0 degrees are nearly identical to the performance declines
from 50 to 100 degrees. An 8:30 runner could expect almost equal effects of
temperature on performance at 100 degrees and 0 degrees. We all knew heat was a
killer for running pace, but I, for one, did not know that cold could have an
equal effect.
Suddenly my lackluster performance in the 5k at 3 degrees
did not look so bad. I had been hoping to run around a 7:15 pace that day but
had run 7:45. According to the chart, that would be just about right on.
So why is this important? Well first of all it can give you
an idea of how to pace yourself on those cold days. You will not be running a
PR, and to try by going out your normal 5k pace is setting yourself up for disaster and
a really ugly last mile or so. Adjust your pace and expectations to fit the
conditions. It also can give you the confidence to know that your training is
working even if the race times aren’t showing it right now. It also can help
when trying to do quality training in cold weather. Just as you would not
expect to run intervals and hit a target pace in 90 degree weather, you should
probably not expect to hit that pace in 10 degree weather either, even if the
roads are clear.
Yes, I still hate winter, and yes, I will still avoid
running in cold weather whenever possible, but when I do race in cold weather,
it is good to know what to expect and how to take into account conditions.
I love the hat! I wish there were more races that gave things other than T-Shirts.
ReplyDeleteIncredibly informative as always. I'll be passing this information on to my running friends. Thanks!
ReplyDeleteThat looks like my hat, medal and AG award. Wait, I think it is. :-) Now that I know how the temps impact my pace, how about ice, snow & yak-trax?
ReplyDelete