How Running in the Cold Impacts Race Performance

Winter is already upon us, and many runners are looking ahead to their final races of the year before some down time.

There are still a number of Turkey Trots for Thanksgiving, Christmas Day runs, and New Year’s Day races with good competition and maybe even some holiday-themed prizes.

When racing and working out at this time of year, the temperature is a concern for runners all over the country. Not only do many runners think running in the cold is bad for you, but it’s not an appealing thought to be standing on the starting line shivering in your spandex.

Today, we will look at the effects of cold temperatures on performance.

While it’s well-known that performance is impaired when it’s too hot, it’s also likely that performance will be impaired if it’s too cold.

The research on running in the cold

First, we will take a look at the scientific literature to see what happens to your body when it exercises in the cold. As is often the case with environmental factors, the military has taken a keen interest in the physiology of exercise in the cold.

This was the topic of a 1991 review by Thomas Doubt at the Naval Medical Research Institute. In this article, Doubt lists a number of changes that affect the body during exercise in low-temperatures:

• You rely on carbohydrates more and less on fats for energy

• 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)

• Your muscle contractions are less powerful, which demands an increase in fast-twitch muscle fiber usage, perhaps explaining the higher lactate production

All of these adaptations have consequences for running: relying more on carbohydrates will drain your energy reserves faster on long runs, and could spell trouble in a winter marathon. Higher lactate production, and less efficient muscle contractions are also problematic for shorter races.

Fortunately, Doubt points out that these effects can be mitigated with warm clothing and moderate activity (like jogging) to maintain your body temperature. However, short to medium-length bouts of high-intensity don’t seem to be as effective at boosting body or muscle temperatures. This means it is best to use a continuous workout rather than short bouts of exercise as once you cool down you will struggle to warm back up during a race or workout!

Potential reasons for performance decline in cold weather

Reviewing more recent literature, in a 2006 article, Lawrence Armstrong (not Lance, don’t worry!) at the University of Connecticut speculated that some of the performance drops associated with cold weather may be the result of having a higher baseline metabolic rate, which is one of the body’s mechanisms to maintaining core temperature.

Shivering is a good example of this; though your metabolic rate is higher in the cold even when you’re not shivering. Armstrong suggests this could “steal” energy that would otherwise be used for athletic performance.

Armstrong also cited several studies which demonstrate that dehydration is a risk in cold weather, as low temperatures increase urine output and diminish thirst. Water losses from breathing and sweating remain significant, even in cold temperatures, so staying hydrated should be a priority.

How the body adapts to running in the cold

A 2004 review by Myra Nimmo at the University of Strathclyde in the UK looked at how the body’s adaptations to cold vary based on the temperature outside.

Nimmo reworked many of the findings of Armstrong and Doubt; your body burns more carbohydrates, less fat, and has higher oxygen consumption at a given exercise intensity in colder temperatures.

Explosive power is also limited by the temperature of the muscles (which, Nimmo points out, can be significantly different to the body’s core temperature).

Nimmo found that these physiological changes become more drastic as your core temperature drops. This means from a performance standpoint, it is critically important to keep your body warm at all times when exercising in the cold.

She also noted that even though many of the military and athletic studies are done on “athletes”, endurance runners are especially vulnerable to performance deficits from cold temperatures due to their slim build. Environments that are cold and wet are also problematic, as they dramatically increase heat loss and render many fabrics ineffective.

According to Nimmo, the ideal temperature for endurance exercise is somewhere around 52 degrees Fahrenheit.

Final thoughts on running in the cold

From all of these studies, we can conclude that running in the cold can impact performance. Thankfully, our look into the research also revealed some helpful tips.

• It is important to stay warm before and during a workout or a race in the cold. As Doubt points out, it is much harder to bring it back up once it has dropped. Warming up before a race or workout becomes even more critical in the cold.

• Maintaining your carbohydrate and fluid intake levels are also important, as you’re more likely to “hit the wall” in training or in a long race during cold weather. Dehydration is a big risk too. To make sure it does not happen to you, read more research on the science of hitting the wall.

• Layering is always a good idea in the cold; it is easier to calibrate your optimal clothing level when you have several thinner layers versus one thick one. If you’re going to train or race in cold weather frequently, it’s probably worth investing in some technical cold-weather clothing, especially if you encounter cold and wet conditions frequently. Here is our guide to winter clothing and what to wear for any given temperature.

• Bitterly cold days are often not as bad as 33° and rainy; rain can make otherwise warm clothes useless. If you find yourself running in cold rain often:
  • Buy latex gloves. Latex is water proof; you can wear the latex gloves under or over your mittens. This will keep your hands dry. Once they get wet, your fingers are going to hurt!
  • Wear tight clothing. Loose clothes will sag more and weight you down. Not only will tight clothes feel more comfortable, but because they are closer to your skin, they can create a layer of warmth similar to that of a wetsuit.
  • Put Vaseline on exposed parts of your skin. Vaseline is water-resistant and it will help keep you warm if it’s windy.
  • Put newspaper in your shoes immediately after your run. The newspaper will soak up the water and help your shoes maintain their structure. Do not put shoes in the dryer or the oven – it will shrink the material and lessen their shelf life.

• It is better to start out a race or workout with too many layers on than not enough; you can always take something off during the race. Many larger races donate clothes found along the course to charity. Take a trip to your local thrift store and but a few $2 sweatshirts you can wear and throwaway mid-race without concern.

• If you have trouble staying motivated in the cold, read this 5 tips for winter running motivation.
• Finally, it will probably pay off to be realistic: just like you can’t expect to run at your best when it’s 95° out, the same goes for a 15° turkey trot. While you may not hit your PR, you can still get a competitive edge on other runners who aren’t prepared for the effects of cold temperatures.