Ski Training for Runners

From Running Director Heidi Caldwell.

Running in Vermont in the winter is largely regarded as a sacrilegious act. Skiing is a way of life here, deeply embedded in the state’s culture, identity, and economy. Recreate however you please in the non-snowy months, but when it snows, you ski. Working at an Outdoor Center with a renowned Nordic trail system, I am reminded of this philosophy daily, because “why run when you can ski?”. 

The prospect of training through a northern Vermont winter for late February’s Olympic Marathon Trials was, naturally, daunting. Training on snowy, icy roads with unpredictable footing seemed far less than ideal, not to mention the tantalizing proximity of ski trails and mountains. I primarily identify as a runner but am also an avid skier, making powder days a struggle of wills - to run or to ski? At the outset, I was skeptical of using skiing for much of my training. Now two months in, I’m beginning to think winter training may be ideal for the runner-skier in me. While I’m a lover of all modes of skiing - backcountry, Skimo, alpine - I will focus here specifically on the merits of cross country skiing as a training option for runners.

The running limit

There is a clear ceiling when it comes to running training volume. Any runner who has tested their mileage limits and found themselves injured can attest to this, myself included. Running is a highly efficient workout while placing a high stress on your body, forcing a cap on how much of it we can do in a given week or session. This in itself is one of the most beautiful things about running: You can only do so much of it. In theory, this simple fact keeps us runners fresh, healthy, and great at time management. In reality, respecting the running ceiling and not overdoing it is far easier said than done.

This inescapable cap on running volume limits the training hours, and therefore the aerobic capacity, a running-only athlete can achieve. As someone who has never done well with high mileage and is new to the marathon distance, my running volume cap is relatively low. In my marathon build-up this past fall, my weekly mileage peaked out around 70 miles per week, a low load for a marathoner looking to break 2:45. Without the physiology or training background to sustain more mileage without injury, this put a definitive limit on the amount of running I could do.

The skiing bonus

For my current marathon build-up to Atlanta, I’m working to increase my total training volume by adding skiing to my regular weekly routine. Cross-country skiing is a low-impact, highly-aerobic activity. Some studies point to cross country skiing as the hardest sport and the highest VO2-max workout out there. With it’s full-body muscle recruitment and high cardiovascular demands, skiing is an endurance gold mine. Mixing skiing into a running-centric training plan removes the stress of pounding while adding huge aerobic and strength gains. 

When it comes to specific strength, skiing is a great resource for runners. Skiing targets the big three muscle powerhouses: glutes, hamstrings, and core. Skiing also does a great job of recruiting the adductors and other small stabilizing muscles that aid in running and injury prevention, but are not easily accessed through road running. Need more perks? The targeted strength demands of skiing are low load and continuous - perfect for a long distance runner. Even better, this is a strength workout you can do outside, away from the gym. 

One of the greatest advantages of using skiing for running training is it allows you to extend time on feet. This is particularly advantageous for marathon or ultra runners. It is far easier on the body to go for a three hour ski than a three hour run. Skiing three hours at a steady pace is taxing, but not in the same way an equivalent length run is. More three hour sessions boost not only aerobic capacity but also mental fortitude. After a few three hour skis, two hours on the road suddenly feels very manageable.

Another way to harness the potential of extended sessions is through “brick workouts”. Brick workouts denote the idea of “stacking” one mode of training on top of another. In this case, a run on top of a ski or vice versa. For example, two weeks ago I did a two hour run followed by a quick snack and change of clothes before hopping on skis for another hour. Next up, I plan to try out a two hour steady ski right into a 30-40 minute tempo. This would effectively mimic the final miles of a marathon, running at pace on fatigued legs, without the physical toll of a similar running-only effort. 

Finding the right mix

Skiing, of course, is not the perfect training for runners. Nothing mimics running like running. It would be hard to be competitive at Trials if I stepped to the starting line having only skied for the past three months. Over time, skiing builds up extra muscle you don’t need for running. There is a point where this added bulk makes the mechanics of running more taxing and less fluid, impeding your running economy. 

There is also a significant differential in cardiovascular stress between skiing and running. Skiing quickly elevates your heart rate on uphills but also allows it to lower substantially on downhills. In contrast, running puts a steady, constant demand on cardiac output. Given this inconsistency, I generally equate a 90 minute ski to  a 60 minute run of equal effort. Though not a 1:1 training equivalent, this differential highlights an important advantage: it is easier to go easy on skis than on foot. Despite all of our best intentions, most runners struggle to make their easy days truly easy. This means we are trying to recover in a perpetual “Level 2” or the dreaded “gray zone” training state. Skiing helps keep your heart rate in check and make recovery days true recovery days. 

So, what’s a runner to do? For this training cycle, I am focusing on doing my intensity days on the roads and my recovery days on the ski trails. Logging intensity on foot works the turnover, leg speed, and mobility needed to be fast on the roads. Skiing on recovery days gives my body a break from high impact of running while still getting a quality aerobic workout. As race day nears, I will start phasing out my hefty ski days to help ensure my body is primed and ready for a fun, fast marathon. 

The takeaway

Run less and ski more to gain a great deal more aerobic fitness, mental toughness, and training flexibility. Long term, consistency is key when it comes it running training. It is far more effective to do a little less running and a bit more cross training than it is to have the “perfect” training for 8 weeks and wind up injured. Accumulated training years is one of the most important indicators of running ability and fitness potential. Months of limited or no activity due to injury greatly diminish your stock pile of training years. Skiing has the potential to help you extend uninterrupted training years and decrease time on the injured bench. 

Use this to help you get creative and adventurous in your training. Remember that training plans will look different for each runner depending on training background, target race distance, time goals, and more. For me, this means using my skiing background to train for the biggest marathon of my career. Trust and listen to your body as you experiment with skiing and other modes of cross-training. Be confident in the power of non-traditional, alternative modes of training and, perhaps, achieve your healthiest, strongest fitness and mindset.

Snack break on a long easy classic cruise with friends.