The Science of Cross Training To Build Trail-Running Fitness
This article originally appeared on Trail Runner
We tend to think of cross-training as the ugly stepchild to our preferred sport or what runners are forced to succumb to when injured. But as the winter months approach and many look to bring their volume and potential intensity down through the holidays, is it possible to utilize cross-training to gain fitness and improve running economy?
We are fresh off the NCAA Cross Country Championships, held in Charlottesville, Virginia, where female champion Parker Valby (University of Florida), sent waves at the pre-race press conference by disclosing that she ran a maximum of two to three days per week this fall, supplementing the remainder of her days with a lot of elliptical and cross-training sessions. Valby sustained calcaneal and cuboid stress fractures in early 2022 and has been vocal about wanting to avoid running-related injuries moving forward. She confirmed that she participated in workouts and "occasional" long runs. This is a unique training model for a Division I athlete of her caliber but could provide insight into the evolving approach to high-level run training while minimizing injury and maximizing longevity in the sport.
To get better at something, you often need to do more of the activity consistently. This includes maintaining base fitness between training cycles, a critical component in lessening the risk of running-related injuries during race season. If you are coming off a hefty fall season of racing feeling incredible or feeling slightly burned out, healthy or nursing some lingering twinges, a masters athlete aiming to take a preventative approach to running-related injuries, or simply looking to diversify your training without adding more high-impact stress on the body, implementing cross-training into your routine could be of huge benefit. But what types of cross-training are most ideal to build running-specific fitness? Let's dive into the modalities that best mimic running movement patterns and maximize running economy gains and how to implement them into a training plan.
RELATED: The Secrets to Success of Cross-Training for Trail and Ultrarunners
The Science Of Cross-Training For Running Performance
A study from 2018 assessed the effects that different cross-training modalities have on running performance and injury risks. The researchers compared movement quality, running economy and performance, injury-related biomechanical variables, and hip muscle strength before and after training with different cross-training modalities in high school runners. In the study, runners replaced two days of easy running per week with four-week cross-training sessions. The runners were separated into three groups: cycling, indoor elliptical, and outdoor elliptical bike (the equivalent of an Elliptigo bike). The study found that elliptical bike training improved functional movement screen scores and running economy before and after training and was the only modality to improve these. All groups demonstrated improvements in 3,000-meter performances, but large effects were only found in the cycle and elliptical bike groups. This underscores that both may be the most effective cross-training modalities to incorporate in early-season training to improve running performance.
RELATED: 13 Cross-Training Exercises Runners Can Do At Home
Another study from the Journal of Strength and Conditioning Research performed a similar four-week study on experienced runners, having half the group do elliptical bike-only training and the other half do run-only training. The researchers assessed maximal oxygen consumption, ventilatory threshold, respiratory compensation point, running economy, and 5,000-meter time trial fitness. The study found no significant differences between the two groups, with a significant increase in ventilatory threshold for both groups and no significant group differences for any of the variables tested at any time point, suggesting that elliptical bike training can be a very effective cross-training method to maintain and improve physiological and performance variables in experienced runners.
A retrospective study from 2019 surveyed about 300 lifelong runners with an average age of 50 who had previously attended a four-day workshop on how to become lifelong runners, spanning from 2007-2018. The study examined the participants' running frequency, injuries, body weight changes, and supplemental training as they aged. The researchers found that 88 percent of the runners implemented cross-training into their training, with indoor cycling being the most commonly chosen method. Ninety percent of all participants surveyed stated they were still running. For those over the age of 60 compared to those under the age of 60, there was no difference in running interruption due to injury. The study concluded that the participants could continue their favorite physical activity (running) after 60 and beyond with the intentional implementation of weekly cross-training.
RELATED: 4-Week Plans for Running, Nutrition and Cross-Training
A Coach's Take on Cross-Training
Specificity is always king in getting better at one's chosen sport. In general, consistency over time and adding more miles to the aerobic fitness bank leads to steady improvements for runners, especially those newer to the sport or who have lacked consistency in the past. However, it's a fine line to toe with running-related injuries and, for some, mental burnout. For others, it can be as simple as weather and accessibility. For many high-level trail and mountain athletes - take Kilian Jornet and Emilie Forsberg as prime examples - living in the mountains of Norway, access to run in their preferred environment becomes impossible in the winter months, and as a result, they both transition to skiing as their primary mode of training. For this article, I will focus on the most common indoor modes of cross-training that are more readily available to most of our readers.
So, who benefits from implementing cross-training into their training, and how should each of these groups weave cross-training sessions into their training? There are always nuances to questions like this, but I'll guide you through the decision-making heuristics I use with my athletes, elite and amateur alike.
Athletes looking to increase their overall training volume may not feel confident in their body's durability to start implementing run doubles (running twice in one day). Science tells us that we can obtain similar, if not identical, gains in maximal oxygen consumption and running economy via cross-training, with an elliptical bike demonstrating the most crossover to running. Running in the morning, anywhere from 45 to 80 minutes, followed up by an afternoon cross-training session of 30 to 40 minutes, could be very beneficial for this demographic of runners. This can be a great, non-impact way to transition runners to take on run doubles. It can also be of benefit to runners who need to focus on time on feet vs. mileage (i.e., when training for a marathon, if a 20-mile long run takes upwards of four hours and poses too much of an injury risk) and can help build the aerobic engine in a safe, low-risk way.
RELATED: The Do's and Don't's of Cross-Training
Cross-Training For Masters Athletes
Masters athletes. As we age, the focus has to shift towards recovery and the prolonged time it takes to recover from higher intensity and high volume work, or else injury risk eclipses any gains being made. Building in an active recovery day, via 45 to 60 minutes on the elliptical bike, indoor elliptical, or bike, following a day of speedwork or a long run can help flush out the legs without adding unnecessary impact and stress to the body. Replacing easy recovery runs with two sessions of easy effort cross-training could yield the same fitness stimulus with less running-related injury risk.
RELATED: How Cross-Country Ski Training May Change Your Thinking On Running
Cross-Training For Adolescent Athletes
Adolescent athletes, particularly in the off-season. Early specialization has been known to lead to a myriad of issues for young athletes, including injury, mental burnout, and the development of eating disorders. Similar to masters athletes, intentionally structuring two days per week of cross-training, at no more than 45 to 60 minutes at a time, in place of two days of easy running can help prevent overuse injuries and also helps the adolescent athlete gain confidence in themselves ahead of their track or cross country season. A study from 2023 found that adolescent long-distance runners perceived a lack of cross-training ahead of their season as significantly contributing to running-related injuries.
RELATED: Cross Training Can Make Some Athletes Stronger And Faster
Cross Training To Improve Running Cadence
Athletes looking to improve their turnover but who cannot tolerate an additional day of running speedwork. Again, specificity will always take the cake here, but it is possible to mimic higher turnover and reinforcement of these movement patterns via cross-training. This can be structured in numerous ways depending on the athlete. It can look like a 45 to 70-minute cross-training session that ends in 20 to 30-second strides on 30 to 60-second easy recovery, just as an easy run with flat or hill strides could be structured. These sessions can be extrapolated to include longer intervals like 10 to 15 one-minute intervals at 5k to 10k effort on equal one-minute easy recoveries, to more prolonged threshold efforts such as five rounds of five minutes on 60 to 90 seconds of easy recovery. I recommend structuring these types of sessions on an elliptical bike, indoor elliptical, or bike and keeping an eye on heart rate for the intervals, as variation in modality can impact one's ability to mimic the same heart rate for equivalent running efforts.
RELATED: The Science of Hemoglobin Mass and Endurance Performance
The Mental Benefits of Cross-Training
Athletes who are feeling burned out over running. Logging many miles and jumping from training block to training block can be a recipe for hating the sport that an athlete always loved. Still, the thought of losing fitness by not running often keeps these athletes in an unfortunate holding pattern. Mixing things up via cross-training can be a great way to ease that fear, lessen the likelihood of impeding running-related injury, and keep the athlete feeling like an athlete. For this group, it's important to keep everything easy and aerobic for a couple of weeks, then slowly add interval-type work to keep them feeling fresh. Maybe even more important for this group of athletes is to not fixate on the types of cross-training that are most specific to running or yield the most fitness gains. Instead, choose what sounds the most adventurous and fun to get the mind back to approaching exercise as play.
RELATED: The Evolution of Running Training Theory
Cross-Training For Injury
Injured athletes: the most commonly associated demographic who employs cross-training. It's never fun to be injured, but the science should comfort athletes going through a rough patch, clearly demonstrating that aerobic fitness, maximal oxygen consumption, and running economy can be maintained and developed through cross-training. The most pertinent point here to underscore is that if you are an athlete going through injury, and depending on your level of training, you do not need to try to get in the same amount of training hours that you did while running, especially if you were frequently logging two to three hours and beyond for your long runs. Mixing in two days per week of interval sessions, aiming to do one session per week that incorporates longer threshold work and the other session being shorter, higher intensity work, and the remaining four to five days at a consistent, easy effort is enough to maintain and grow your fitness. It's important to strike a good balance between allowing the body to heal and recover (and also closely depending on the location of injury and clearance from your medical team to do these types of cross-training workouts) and not throwing it into overdrive with excessive cross-training.
RELATED: Ultra Legs, A Strength Routine For Ultrarunners
Is The Cross-Training Juice Worth The Squeeze?
For many athletes, cross-training is optional in their training. Still, it poses a great option for specific demographics of runners - and not just those forced to cross-train due to injury. Some athletes will benefit more from implementing cross-training into their training than others, and it's a theory that takes refinement to decide if cross-training is the best option for the athlete. The evidence above demonstrates that it can be helpful when balanced correctly and intentionally in a well-rounded training program. Above all else, maintaining and gaining fitness should be fun, regardless of fitness level, and cross-training can bring a fresh, new take to one's training while lessening the risk of running-related injuries.
For exclusive access to all of our fitness, gear, adventure, and travel stories, plus discounts on trips, events, and gear, sign up for Outside+ today.
