Can Hanz and Franz help you out? The seemingly endless debate of weight training for endurance athletes will carry on for decades. I do not plan to solve this in a single super-human blog posting today, but lets take a stab at this form an injury stand point, and hopefully give you some food for thought to modify your training program.

As an endurance athlete, your muscles receive a LOTS of high volume loads

• Cross sectional area is important to disperse load. There’s the old question – “what puts more force per square area on the ground – an elephant or a woman in high heels?” – answer – the high-heeled woman. Don’t worry, I’m not calling her fat! The elephant weighs a ton….or tons, but has 4 very wide contact points to disperse his weight. The lady weighs a small fraction of the elephant’s total weight, yet the small stiletto heel and small forefoot disperse this weight through a very small area. What does this have to do with muscles and tendons?
  As you train, your body’s tissues are under a lot of stress. As you sweat along to your iPod, they generate tremendous amounts of force to move your body through space. Small muscle and tendon thickness means that there are greater peak stresses inside these tissues. A larger thickness (cross-sectional area) of these same tissues means that peak strain inside the tissue would be less.

• Cross sectional area decreases with age. Along with bigger ears and longer noses, we lose muscle mass with age. Sorry – don’t shoot the messenger, it just happens.  This is not the end of the world though as studies have shown that even men in their 80’s can increase lean body mass (muscle mass) through strength training.
• The way to increase cross sectional area is through strength training. “But wait- I am an endurance athlete – I am strong! – I train 25 hours a week on the roads, pools, and running paths!” No doubt you are ahead of the curve Mr./Ms Endurance Athlete, but there is a difference. Endurance training is primarily high volume low load training. This is not the specific stimulus to get increases in cross-sectional area within our muscles. The correct stimulus to increase the thickness of muscle and tendon tissue is to lift heavy. You are looking to lift a weight 5-7 times for 1-3 sets with a weight such that you can barely complete the number of reps in each set.  Endurance athletes are frequently told to focus on lifting for muscular endurance (high reps, low weight) – this type of lifting program does not target increasing tissue thickness (called muscular hypertrophy).

So what is our take home message from today? Is it that we should all begin lifting heavy starting today? Obviously not. The take home message is this. Increasing the thickness of your musculoskeletal system will help disperse the loads our body sees with chronic training volume. Younger athletes normally develop these characteristics. As we move into our 20’s and 30’s, some amount of true strength training is likely beneficial as part of your training throughout the season. As we move into our 40’s, soft tissue density decreases. This means we can’t deal as well with training stresses and may be more likely to develop strains and injury. That’s all for now – time to hit the gym.