Mastering Cold-Weather Endurance: Lessons from a U.S. Biathlon Athlete

By Vincent Bonacci

I am a member of the United States Biathlon Team, a sport that combines cross-country skiing and shooting. This means that in addition to the rigors of training and competing in any endurance sport, I have to contend with the challenges that arise from doing so outside during the winter. Over the past few years, I have made numerous mistakes on this front, and while that can be frustrating in the moment, I have been lucky to learn from those mistakes and reach a point where I can say that I have my winter training and racing routines solidified, allowing me to go into the season confident in the knowledge that I am not leaving anything obvious on the table. 

While it may sound simple, the most important element of performing through the winter season is the ability to stay healthy. Due to the increased risk of infection in the colder months, it is crucial to avoid the nutrient deficiencies, viruses, and head colds that can derail training and keep me from performing at my top level. To that end, I never skimp on my vitamins when I am training or racing. I love to use products like MultiV and HALO, as they give me everything I need in one trustworthy formula, instead of trying to mess around with taking a bunch of individual supplements every day. Outside of supplements, making sure that I stay as warm and dry as possible is key to staying healthy. 

The other most important consideration when training and racing in the cold is fueling. I personally always err on the side of overfueling for races and training, and I have found that to be far and away the most effective way to keep my energy levels up through the winter race season. In the cold, even if it seems like you’re going super easy, your body is using a lot of energy just to stay warm, so if in doubt, always eat more for fuel and recovery than you think you need.

With that in mind, here are the strategies I implement during training and racing to stay healthy and well-fueled. My normal winter training day involves a combination of skiing and shooting, coupled with a light run or strength session. In order to fuel that work, I almost always start the day with a bowl of oatmeal or muesli with yogurt and coffee, and some fruit if it is available. After breakfast, I assemble all the things I will need for the workout and head to the venue to start training. In order to help me stay warm and healthy, I always bring extra gloves for warmup and cooldown, some warm EFS in an insulated bottle, and dry clothes to change into immediately after the session. If I am doing intensity, or skiing for longer than 90 minutes, I also bring a Liquid Shot or two, which I find keeps my energy up without causing any GI distress. Immediately following training, I make sure to drink a serving of Ultragen, which is the most convenient way for me to start the process of refueling and recovery before having a small meal when I get home. 

On race days, I try to keep my fueling as similar to training as possible, as I find that this minimizes the risk of bonking, cramping, or being hit with GI stress during competition. Most of my races are held in the late morning, so it is quite easy to plan from breakfast to the race. For breakfast, which I eat 3.5 hours before race time, I almost always go for my trusty oatmeal with yogurt. The yogurt adds some protein and flavor, and importantly for me, it thins the meal out so that I am able to eat a decent portion. I always try to get down as much as I can, as this is my last “real food” before the race. Where my routine differs a bit on race day, however, is in how I fuel from breakfast until the end of the race. My competitions last between 25 and 50 minutes, and I have to be able to sustain 92% or more of my max heart rate over that duration. That combination of intensity and duration means that I aim to take on all of my fuel before the race begins, as I tend to have a hard time getting anything down when I am gasping for air. Additionally, I get extremely nervous before competition, so I struggle to eat any foods that take too much chewing, or have too much flavor. If you are able to eat more luxurious foods, I am jealous, but sticking to liquid carbs is what I have found works well for me. 

My go-to fueling strategy on raceday is one 500ml bottle with about 300ml of EFS and a scoop of PreRace in it, and another 750ml bottle with only EFS. I sip from the EFS bottle until about 40 minutes before the start, at which point I drink all of the PreRace at once, as I want to make sure that I have the full effect of the caffeine at the start. One thing I have added to my routine more recently is having a Liquid Shot in the final 30 minutes before the race begins. 

On the rare occasions that I do a race long enough to require fuel during, I use a high-concentration bottle of EFS-PRO. It’s the only high-carb mix I’ve found that has a mild enough flavor to allow me to get it down while I’m on the limit. Post-race, I always go for a full serving of Ultragen, which is easy enough on my stomach to allow me to get it down, even when my mind is telling me that I need anything but food. Getting those carbs and protein immediately after a hard effort is the first step to recovering well enough to sustain me through an entire winter race season.