Why do I slow down in the cold?

I don’t know about you, but once the temps outside dip below 40 degrees my athletic performance is drastically impacted. My muscles just don’t seem to "fire" as efficiently as they do when it’s warmer out. I’ve always wondered why that is and if there’s anything I can do to lessen the impact. So I set out to research the topic.

A number of changes that occur during exercise in low-temperature settings:

1. Your body relies more heavily on carbohydrates and less on fats for its energy. This will drain your energy reserves faster on longer rides/runs.
2. Your lactate production is higher for a given intensity, indicating that you’re going deeper into “oxygen debt” to produce the necessary energy to maintain a given pace (as evidenced by a higher oxygen consumption rate in colder temperatures).
3. Your muscle contractions are less powerful, which demands an increase in fast-twitch muscle fiber usage, perhaps explaining the higher lactate production
4. A higher baseline metabolic rate, which is the body’s mechanisms to maintain core temperature.  This could steal energy that would otherwise be used for athletic performance.
5. Dehydration is a risk in cold weather, as low temperatures increase urine output and diminish thirst. You lose water from breathing and sweating even in cold temperatures.

The third reason above made the light bulb go off in my head. I’m more of an endurance athlete than sprinter. Years ago during performance testing with Robbie Ventura, he turned to me and said “You are like a diesel engine. You take a long time to warm up, but then you just go and go and go.” It was and is such a true statement. But definitely not something a woman wants to hear...“you are like a diesel engine.”

I tend to believe my body composition is made up of a higher percentage of slow-twitch fibers than fast-twitch. This explains my endurance capabilities vs lack of sprinting ability. I take about 10 miles to warm up on the bike. I’m gasping for air trying to keep up with the pack. But then after those 10 miles, I’m good to go. Knowing your own body will definitely help you prepare for a race or even simply a group ride/run. Prior to Robbie’s diesel engine comment, I would not spend much time warming up before a race. As a result I’d experience a very high heart rate the first 15 min of the race. So I changed my routine and would always do at least a 20 minute pre-race warm up. My race times improved immediately.

So, how do you lessen the effects of cold weather on your performance?

•  Stay hydrated...before, during and after the ride/run.
•  Keep your body warm before and during exercising. It’s harder to bring your body temperature up once it has dropped.
•  Wear several thin layers versus one thick one.
•   Invest in cold weather technical clothing. Also clothes that wick moisture away from your body. On windy days a wind proof layer on top can be very helpful.

Knowing the physiological reasons why your performance diminishes in colder weather may help you in your training. I know I’ve learned a few things researching for this post.

Stay warm, stay hydrated and enjoy the ride.

Sheri