Cross-Training: What's The Point?

Cross-training is often the most overlooked part of a runner's training cycle. Intuitively, it makes sense that the best way to train for a marathon is to run more and run often. But like any other sport, developing the different systems of your body is important for improving your body's ability to adapt to the demands of the sport. Consider soccer players - they may scrimmage and run drills often, but the time they spend in the gym is what makes the difference in how powerful their kick is. 

It's not as obvious in endurance sports where the competitive advantage is found, so it can be easy to skip cross-training days and treat them as rest days instead. While rest is crucial to a successful running cycle, it is completely different from what cross-training does for you. Today's blog will explore why you should cross-train, and what it might look like. Furthermore, we will dive into why MOTIVNY's classes will be your best friend for smart cross-training programming.

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Below are a few big reasons why you should cross-train:

  • Improve the resiliency of your joints to avoid injury
  • Strengthen your running muscles to improve your running power
  • Strengthen your NON-running muscles to keep your body balanced
  • Work on your mobility to combat the repetitive nature of running

While these reasons are valid for all runners, which ones you prioritize may depend on your body, your running experience, and where in your training cycle you are. For example, your off-season is the best time to strengthen your running muscles, while the mileage demand is low. On the other hand, mobility and joint resiliency become more and more important later into your training cycle as the load on your legs add up. That being said, both are always essential for a healthy productive training cycle. From here, we are going to explore the difference between HIIT and weightlifting for your strength goals. For tips on mobility, check out this blog on Kinstretch by Doctor of Physical Therapy James Chung.



High intensity interval training may seem like a perfectly acceptable method for cross-training, and is certainly one of the most common types of classes offered in NYC fitness studios. While HIIT training can be a great way of increasing your lactate threshold (read: improve your cardiovascular economy), it is probably one of the last things you want to be doing as you get deeper into your high mileage weeks of your training cycle.

A good running program gradually increases weekly mileage in a way that doesn't ever overload your body all at once. But by adding burpees, jump squats, etc. to the program, you are adding excessive force and shock through your bones and joints that isn't accounted for in your program. Moreover, you are depleting the energy stores in your muscles that you need for your runs. If you feel worse on your runs because of your cross-training, you will be even less likely to keep cross-training. 



Strength programming in comparison is highly flexible and can be adapted to fit every part of your training cycle, even down to the very last week. During your off season and base building, you should be lifting heavy to build strength and power while your mileage is low. 


As you approach peak mileage weeks, your strength priorities will shift to maintaining strength while conserving energy, as well as emphasizing movements that explore all ranges of motion. Running takes your joints through a very limited range of motion, and your body follows a "use it or lose it" rule - if you don't use your joints to their full capacity, your body will assume that capacity is unneeded and will shrink. This may be why you feel your hips getting tighter when you run without stretching; the secret is that you may actually make more range of motion gains by training strength rather than flexibility. 



You may have seen the class title "Mixed Modes" in the MOTIVNY class calendar. While that title isn't fully descriptive, we named Mixed Modes intentionally in order to allow for flexibility in how we program week to week. Mixed Modes is a blend of strength and mobility work that seeks to fulfill all of the main goals of cross-training. Maximizing your use of time, mobility typically combines aspects of Kinstretch and flexibility training in order to target your joints as well as your muscles, and strength is programmed in a more unconventional way. Compared to traditional strength classes, you'll see a lot of split stances, single-leg work, and other positions that have a highly demanding impact without the need for super heavy weights. Leave class still feeling fresh for your next run or training session.


To learn more about what your body might need on your cross-training days, my best recommendation is that you see a physical therapist to learn where your deficits and limitations are and how to address them. Email us at to learn more about Mixed Modes or to connect with a PT.