23 Mar Strength Training for Endurance Athletes

Todd Buckingham, Ph.D. | Lead Exercise Physiologist, Mary Free Bed Sports Rehabilitation

Strength training and injury prevention

I’ve received some great feedback on my last two blog posts about strength training for endurance athletes. And I just so happened to be chatting with a friend last week and he said that I should write about strength training and injury prevention for the “old people”. Ask and you shall receive! 

I’m sure most of us have been injured at one point or another. It’s hard to define and track injury rates, but up to 75% of endurance athletes have experienced an injury at some point in their career. Many things can contribute to this but the most common cause of injury is due to overuse (in runners, running over 40 miles/week has shown a strong correlation to injury rates). 

This is probably the part where you want me to tell you that strength training is going to cure all that. “Just do some strength training and you’ll stay injury free!” Well, I’ve got some bad news for you. Unfortunately, despite the countless studies over decades of research, there is not sufficient evidence for preventing running injuries with strength training. In fact, there really isn’t any good evidence to show that anything reduces the risk of running injuries. The strongest piece of evidence linking injury prevention to running is that running more than 40 miles a week seems to increase your odds of getting injured by about 3x compared to those who run less than 40 miles a week. Sadly, this is not a reality in which some of us can live due to the nature of our races. Training for marathons, ultra-marathons, and Ironman competitions require a lot of mileage to get the legs used to the pounding they will encounter come race day. 

Another thing that people may do that they think will help prevent injury is stretching – static stretching in particular (this type of stretching is when you stretch and hold for a certain amount of time). There is little to no evidence that static stretching before OR after exercise reduces the risk of injury. In fact, static stretching prior to some competitions (like running) can actually decrease your performance. (Obviously in sports or competitions where flexibility is necessary like gymnastics or diving, static stretching prior to competition could be useful because those sports require increased range of motion, but we’re just talking about endurance sports here). Dynamic stretching (e.g., high knees, butt kickers), on the other hand, has been shown to increase running performance. 

Think of your muscles like a rubber band. If you stretch the rubber band frequently, it becomes inelastic and does not contract as quickly or powerfully as it did when it was fresh. Your muscles act in much the same way. If they are stretched too far and too frequently (through static stretching) they can become inelastic and lose much of the force that would normally be generated. Now I’m not saying, “Don’t stretch”, so don’t twist my words! We must do some stretching to take the joints through their full range of motion. However, this should be accomplished through dynamic stretching and not static stretching. Think about it, how often during a run are you bending at the waist and touching your toes? If you’re doing it right, you should never do that while running! But how often are you performing a movement like high knees (running uphill) or butt kickers (sprinting to the finish)? These exercises are much more applicable to our needs as endurance athletes so we should perform dynamic stretches instead of static stretches. 

A few other things you can do to decrease your risk of injury are:

1. Don’t make sudden changes in your routine or increase mileage excessively (i.e., follow the 10% rule) and 2. Don’t train year-round. Your body needs rest, so take a break at some point during the year (I promise it won’t make you lose all your fitness). 

1. The 10% rule – This “rule” states that you should only increase your mileage by 10% each week (with every 4th or 5th week taking a recovery week). That means if you do 20 miles this week, the following week should be 22 miles (20 x 10% = 22), then 24.2 miles, and then 26.6 miles. Your recovery week should be anywhere from 50-90% of the mileage from your previous training week. If you’re running under 40 miles/week, aim for 50-70% (e.g., 30 miles on week 3 means 15-21 miles for week 4 recovery). If you run more than 40 miles/week, aim for 70-90% (e.g., 50 miles on week 3 means 35-45 miles). In any case, you want to see a significant drop in your mileage during your recovery week to allow your body to absorb the training from the previous 3 weeks.
   
2. Don’t train year-round – This is an important part (or should be if it’s not already) of every athlete’s training plan. Training year-round is a great way to end up injured, burned out, and unfit. I know what you’re thinking, “But Todd, if I take time off, won’t I lose the fitness I worked so hard to gain?!” Yes, you will. And that’s okay! You won’t lose ALL the fitness that you built over the months and months of training prior to that point. And this break usually occurs after the season and only lasts 1-2 weeks. I’m not saying, “Don’t train at all.” Instead, train at your leisure. Do what you feel like doing. If you want to go for a run, go for a run. If you want to ride your bike, ride your bike. If you want to lay by the pool, lay by the pool. This downtime is a physical AND mental break for you after a long, hard season of training. You don’t have to be “on” all the time. Spend time with your family and friends, grab a beer, stay out past 9p…those early morning workouts don’t need to happen now!

HOWEVER! If you DO get injured, this is where strength training can provide some benefit. This is why you see a physical therapist after your injury. They take you through a series of strength and stabilization exercises to help build up strength in the affected area. When you’re injured, the muscles on the affected limb don’t get used as much and atrophy (shrink). One reason strength training following an injury works is that it helps to rebuild those atrophied muscles. In one study, rehabilitation exercises led to a 51% and 35% strength gain in hip abduction in men and women, respectively. This also led to resolution of symptoms in 22 of 24 cases in only 6 weeks (Clin J Sport Med. 2000 Jul;10(3):169-75. doi: 10.1097/00042752-200007000-00004). 

So, the next time you want to do strength training to help prevent injury, just know that it doesn’t actually work that way. That doesn’t mean “never do strength training”. It just means the purpose of your strength training should not be injury prevention.