Why Cross-Training Is Essential (and Improves Your DNA)

Traditionally speaking, cross-training is what you likely imagine it to be: if you are a runner, for instance, you can throw in some cycling or swimming one or two days per week between your running workouts. Or if you are a cyclist, toss in a strength day and some yoga twice per week to break up the cycling workouts.

The benefits of cross-training go far beyond what you expect, and as I will explain, it can actually affect you on a genetic level.

Examples of some cross-training activities include using swimming, yoga, cycling, resistance training, callisthenics, hiking, or even a sport like soccer or basketball mixed in with your regular training each week to help improve your overall aerobic capacity, build muscle mobility, flexibility, balance, and strength. But the benefits of cross-training go far beyond that, and as I will explain in a bit, cross-training actually affects you on a genetic level.

Mixing It Up

Including cross-training in your fitness program allows you to vary the stress placed on specific muscles and your cardiovascular system. It has also been known to reduce the possibility of an overuse or repetitive movement injury that can come from doing a single sport every day.

Let’s face it, after months of performing the same movements, again and again, your body will become very efficient at performing those specific movements. While that is advantageous for sport and competition, it severely limits the level of your overall fitness and also limits your potential for health and wellness in general.

Here is a short list of the more obvious things that cross-training can help with.

6+ Benefits of Cross-Training

1. Keeps you from getting bored with your workout regimen.
2. Allows you to seamlessly adjust your training plan if the weather (or life) gets in the way.
3. Strengthens and conditions your entire body, on many axis/planes of movement.
4. Reduces the risk of overuse or repetitive strain injuries.
5. Allows you to continue exercising parts of your body while the other parts rest.
6. Improves your overall mobility, balance, flexibility, and agility.

Cross-Train Your Sport

While cross-training in the traditional sense is undoubtedly a great idea and I strongly encourage you to do just that, another way to get the deeper benefits of cross-training is to build it into your day as well as your workout program.

In my perfect world, calorie counters would be banned from all exercise machines.

Recently, on my own website at BrockArmstrong.com, I began an article with this statement: "In my perfect world, calorie counters would be banned from all exercise machines. Instead, I would add 'number of limbs moved' or 'variety of planes used' or, even better, I would add a 'level of enjoyment' meter."

The reason I am more interested in the number of limbs involved in an exercise, or the variety of planes (or levels) involved in that movement, is for many of the same reasons that I encourage you to cross-train.

To borrow an analogy from my favourite Biomechanist, let’s think of movement as vitamins for a moment. In the same way that we need many different vitamins to be a healthy and well-fed human, we also need a variety of movements each day. If you simply go for a run most mornings, you are getting more than your RDA (recommended daily allowance) of "vitamin running" but what about your other movement nutrients?

You can equate this idea to eating a head of broccoli most mornings. Sure, broccoli is healthy, but it is missing important micro and macronutrients. Similarly, we all certainly get our fill of "vitamin sitting" but how much of "vitamin hanging" or "vitamin squatting" do we get on a daily or weekly basis? Malnutrition isn’t simply limited to food.

Why does this matter? Well, let me answer that with a study. (Isn’t there always a study?)

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Cross-Train Your Genes

Research from 2014 on the reprogramming of the epigenome and the transcriptome in human skeletal muscle after training showed scientists that exercise actually changes the shape and function of our genes.

The human genome is as complex and dynamic as you can imagine. Depending on what biochemical signals they receive, your genes are constantly turning on or off. When our genes are turned on, they express proteins that trigger physiological responses all over the body, both good and bad.

This is where epigenetics enter the equation. I know this sounds complicated but hang in there—it is worth it!

Research from 2014 showed scientists that exercise actually changes the shape and function of our genes.

What scientists call epigenetic changes occur on the outside of the gene, through something called methylation. During methylation, methyl groups (clusters of atoms), attach themselves to the outside of the gene and make the gene more or less able to receive and respond to those biochemical signals.

Scientists know that methylation patterns change when we make lifestyle changes, like eating certain foods (and not eating others), but a lot less was known about how exercise affects methylation.

Which brings us back to the 2014 study where scientists at the Karolinska Institute in Stockholm gathered 23 young, healthy men and women, and performed muscle biopsies on them. They then asked the 23 participants to exercise half of their lower bodies for three months. Yes, I said half of their lower bodies.

They did this by having the volunteers ride a bicycle using only one leg, leaving the other leg dangling there, unexercised. Ingeniously, this turned one of their legs into a "control group," of sorts. Both legs would experience methylation patterns that were brought on by their normal everyday lifestyle but only the leg that did the pedaling would show the changes related to exercise.

After the one-legged pedalling at a moderate pace for 45 minutes, four times per week for three months, the scientists did more muscle biopsies and calculated the results.

The researchers found that more than 5,000 sites on the genome of the muscle cells from the exercised leg had new methylation patterns. And the genes that were affected are genes that are known to play a role in metabolism, insulin response, and inflammation within muscles. In a nutshell, the genes that were methylated are the ones that affect how healthy and fit we are.

The gene changes were not found in the unexercised leg.

After all this, how does this relate to cross-training? Well, here’s the thing: the gene changes were not found in the unexercised leg. Do you see where I am going with this?

Ok, back to the vitamin analogy. Let’s say that you get plenty of "vitamin walking." The genes associated with how healthy and fit you are get expressed in the muscles you used for walking. But, like the unused leg of the cyclists in the study, the rest of your muscles are left unnourished and those genes are left unexpressed.

This is exactly why cross-training, not only in your chosen sport but in your general lifestyle, is so important. It is also why I am much more interested in tracking "planes of movement" and "number of limbs used" than I am in counting calories. (Even if the calorie counters were even close to accurate).

10 + Ways To Cross-Train Your Day

So, aside from making sure you get all the benefits of cross-training in your fitness regimen, how can we add more vitamin-rich movements into our day? I am sure you can get creative but here are some ideas to get you started.

1. If you sit down to put your shoes on, try standing.
2. If you usually pick things up off the floor by bending at the waist, try squatting.
3. When it is not dangerous (or too awkward), walk backwards or do some side gallops.
4. If you usually carry a backpack, try carrying it on your chest or in your hand.
5. If you use the computer mouse with your right hand all day, try using your left.
6. If you have been sitting in a chair during the day, sit on the floor in the evening.  
7. Simply get your arms up over your head, I bet you don’t do that very often outside of yoga class.
8. If you usually hold your phone down by your stomach, hold it up right in front of your face.
9. When you are waiting for the coffee to brew or the street light to change, do some arm circles, knee bends, ankle rotations, shoulder rolls or simply move any other body part you can think of.
10. If you only pedal your bike with one leg, try pedalling with both!

Move as many limbs, in as many directions, on as many planes as you can.

If you are a runner, it is a good idea to cross-train in the weight room to build strength and stability. If you are a weightlifter, throwing in the odd cardio session or yoga class can be a great way to help stay flexible and lean. If you are a swimmer, hitting the rowing machine or elliptical trainer can be helpful to avoid repetitive use injuries. And if you are a human on this planet, moving as many limbs, in as many directions, on as many planes as you can is one of the best ways to stay healthy and fit on a genetic level and beyond.

At the conclusion of that 2014 study, one of the researchers stated, "Through...a lifestyle change that is easily available for most people and doesn’t cost much money, we can induce changes that affect how we use our genes and, through that, get healthier and more functional muscles that ultimately improve our quality of life." Need I say more?

For more cross-training info, genetic tips, and to join the epigenetic conversation, head over to Facebook.com/GetFitGuy or twitter.com/getfitguy. Also don't forget to subscribe to the Get-Fit Guy podcast on Apple Podcasts, Stitcher, SoundCloud, Spotify, Google Play or via RSS.