I love this analogy: Don’t let your engine outpace your chassis.

It’s a simple analogy that refers to your metabolic or aerobic fitness (endurance) vs. your structural fitness (bones, tendons, ligaments, and muscles). I like to tell my runners that you never want a Ferrari engine in the frame of a Geo Prizm. That engine is going to tear the car apart.

As runners, we need to be aware that “fitness” means a lot of things. It’s your muscular ability to handle the pounding of a marathon on city roads. It’s your heart’s ability to deliver enough oxygenated blood to your working muscles. It’s your muscle’s ability to clear lactate as you start to run faster than your aerobic threshold.

We also need to recognize that different aspects of our total fitness come along at different rates. I’ve learned over the years from experience and other coaches that your aerobic fitness is developed more quickly (and erodes at a slower rate) than your structural fitness.

It’s simple, but let me paraphrase Jay Johnson from this post:

Metabolic changes occur faster than structural changes…and that’s usually why you get hurt. You’re fit and you can hammer 10 miles, but your posterior tibialis can’t handle the stress and soon the inside of your “shin” is sore. Or your gluteal muscles are weak and your IT band tightens during the run and later you can’t run because of your IT band. For some reason you can gain the fitness to run a solid 10 mile, or 15 mile effort before your body is ready for it if all you do to train your body is run. Yes, you can foam roll and yes you can get on a massage table weekly, but athletes need to do a lot of work to get strong (in all three planes of motion) to be able to withstand training paces, volumes and race paces that athletes dream of running.

So learning how to build a strong body is something that’s really important for distance runners. And unfortunately, it’s not something that’s on a lot of runner’s to-do lists.

When I was in high school I never did strength exercises. I think I escaped injury because of low mileage, frequent rest days, and just being a teenager. But then I went to college and increased my volume. The workouts got harder. I was hungry to improve.

I had a good cross country season and ran a lot faster than I predicted. Then all of that training hit me like a ton of bricks: achilles tendonitis, ITBS, and all sorts of aches and pains afflicted the rest of my college career. I had some good races but my training was inconsistent, discouraging, and disappointing.

My Biggest Mistake: Skipping the Strength Work

Throughout college and for years afterward I never went to the gym. My core exercises were inconsistent. I never warmed up for my runs. All I did was run. I was a one-dimensional runner – and we all know it pays to be athletic.

Some elite runners spend more time doing strength exercises and preventative work than they actually spend running. Most of us have other obligations or interests that don’t allow us to spend 2-3 hours working out every day. But to quote Jay Johnson one more time, all you need is 15 minutes.

Pick one of the routines from my definitive guide to warm-ups and core exercises. Most only take 5-10 minutes. There are a lot of ways to structure these workouts, but do something before and after every run. Even if it’s only five minutes.

Here are a few other tips to keep your chassis strong:

Core exercises are great but keep in mind that you should be doing some exercises standing up to mimic the demands of running.

Runners shouldn’t ignore their legs in the gym – squats, dead lifts, lunges, and step-ups can do wonders to keep you healthy.

Yes, you can skip a day of core or strength exercises. You don’t have to be a perfectionist. Just remember that it’s more important what you do most of the time than what you do once in awhile.

For detailed body weight workouts and videos of many of these exercises, check out the Rebel Strength Guide.

Avoiding Injury in the Danger Zone

I think runners should consistently do these exercises all the time. But there’s a specific time when they’re even more important because you’re at a much higher risk of injury: when you start running after a 1-3 week break in training.

Your endurance is the last piece of your fitness to go during a period of inactivity. The first thing to go is your structural fitness – the strength of your muscles and connective tissue to withstand the impact of running.

You can see where this is going: after a break in running, your aerobic fitness is still high but your leg’s ability to endure those early fast runs that feel so good is low. You’re much more susceptible to hurt yourself during this time.

Be cautious during your first 2-3 weeks back from a break in training. Reign in your pace if you find yourself going a little faster than usual – after all, you’re going to feel great since you’re well rested. Core work, gym sessions, or body weight exercises should be consistent. If you’re a runner who’s more likely to get hurt, add more strength exercises than you normally would.

Bonus Strategies to Get Strong and Stay That Way

Staying consistent with your core and body weight exercises isn’t the only way to keep your legs strong. The most running specific way to lift is to actually run hill sprints. While I don’t think every runner should do them (they’re advanced) nor are they a perfect substitute for a quality gym session, they’re a great alternative. Progress slowly and have fun – they’re exhilarating.

A valuable lesson I learned from Brad Hudson in his book Run Faster is that injuries usually happen during volume increases. In other words, you typically get hurt when you’re building your mileage. So the main idea is to maintain a moderately high volume of training year-round instead of taking long periods of time off and always trying to play catch-up with your mileage. Those ramp-up phases are the most dangerous.

More importantly, Hudson argues that high mileage is protective in itself because it “produces adaptations that render the bones, muscles, and connective tissues better suited to handle the repetitive impact” of running. It makes sense and has become a cornerstone of my personal training philosophy. I think it’s one of the reasons that I’ve been free of any major injuries in the last 2.5+ years.

Individualized Training is a Must

Every runner is different. When I work closely with runners, either in my Full Coaching program or a PR Race Plan, I always focus the strength work that they do for whatever weakness they may have. That’s why my Runner Questionnaire is so detailed – so I know whatever I prescribe is highly targeted.

If you’re planning your own mileage, recognize your weak areas and actively work to improve them. Maybe that’s a lack of aerobic fitness or it’s hamstring inflexibility. Or it could be susceptibility to ITBS or runner’s knee. Every runner has certain recurring issues that have the potential to sideline their training.

Know yourself and design your training accordingly. If you’re not sure how to design your training, a training plan or 1-on-1 coach can help take the guesswork out of planning your workouts. And if you don’t know how to do the strength work, learn the exercises with an easy to follow strength program.

No matter how you plan your training, make sure your chassis can support your engine.

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