Cross-training vs. pure running.

I've been asked this question a few times; Why spend time biking, swimming, strength training or performing any cross-training session when can I spend more time running?  The answer really depends on the individual.  The primary focus of new to relatively new endurance athletes should be to improve aerobic capacity.  Teaching the body to tap into fat as a primary fuel source (rather than sugar) is critical in building a solid cardiovascular foundation before performing anaerobic work.  If an athlete has been running consistently for many years (10+) and volume has remained relatively constant, then yes, adding more running volume or speed work is likely the best option to take that runner to the next level. This runner is likely reaching the limits of their genetic potential and therefore needs to spend more time running to improve running economy.

The next few questions I would ask an individual would be; Have you been injured recently or in the past year during higher volume/intensity training? Have you encountered severe burnout or fatigue for long periods of time, or experienced periods of excess stress, depression or anxiety?  Did you peak in the spring with PR’s then remain at the same level the entire summer even with track sessions and frequent weekend races?

Aerobic training is far less stressful than anaerobic training which, if not prescribed or executed correctly can overload the adrenal system, increasing cortisol release; leading to staleness, burnout or injury. All of these side effects can sideline a runner and keep them from continuous improvements.  Our bodies thrive when focusing on aerobic development and the balance of hormones keeps us happy and feeling refreshed after nearly every workout.

Most of the athletes I work with, including myself, are not at the elite level in running performance.  Therefore, building aerobic conditioning should be the primary focus, particularly, for athletes focusing on distances over the 5K.  If we keep adding run volume and our body absorbs this increase, we probably have great running mechanics, durability or a unique hormone profile which helps us to a speedy recovery.  If however, we are prone to injury or burnout, as running volume/intensity increases, then why not add some low impact cross-training to our total training volume to  improve aerobic capacity which can transfer to other sports?   Example; I have a friend that had been purely cycling for most of his life and then took up running for cross-training. Within 3 months he was running 6:05 minute pace for a 5 mile run.  Was this likely due to his 3 months spent running or to his 12+ years spent cycling and improving aerobic conditioning?

In addition, adding drills, core work or full-body strength moves have been proven to increase durability and running economy, particularly for longer distances.   Of course, spending loads of time in the weight room will increase muscle mass, power and durability but is also likely to take away from valuable run-time. However, incorporating a few short (~15-20 minute) strength sessions each week should be a staple in any endurance training plan.