Benefits of Cross-Training: The Real Story

In a recent NYT article, author Gina Kolata elaborates on the research regarding cross-training for sports.  Let's look at her argument and her view of the research that says that Cross Training (by her definition: cycling as a substitute for running or vice-versa) is NOT important and or beneficial for sports.  (NYT article HERE) 

1) Claim #1: "If you want to be a better runner, you have to run — regularly, consistently, and with a training plan that forces you to gradually increase your distance and speed. If you want to be a better cyclist, you have to ride and train according to the same principles. Same goes for swimming or any other endurance sport."   
Why this isn't true: If becoming a better ANYTHING in life was about doing something regularly, consistently, and with a plan, then life would be MUCH easier.  If you had to describe climbing a challenging mountain, it's simple: put one foot in front of the other.  But is it easy?  Many would say no.  This applies to running: doing something regularly and consistently, especially something with such a large injury risk as running (750 hops on one leg = one mile of running) and expecting to just do 'more' is foolish.  The details I used in the 21st Century Runner article are explicit in this: today's runners run SMARTER, not HARDER.  Increasing mileage alone is a 1980's recommendation from a coach that does not understand runners and the injury risk associated with it.  Increasing the variability from one run to the other (high-speed intervals to long slow distance runs) is the 21st Century recommendation to prepare muscles and joints for different stresses.  From shin splits, IT band friction syndrome, low back pain, muscle strains, plantar fasciitis and the dreaded 'runners knee', running is ANYTHING but low-stress and/or risk-free. 

 Above: a Runner's 'Band aid' for knee pain (aka cho-pat strap for patellar tendinitis/runner's knee)

2) Claim #2: "Lifting weights is just the opposite of cross-training (with cycling as a substitute for running, etc) — you do a few repetitions with the goal of increasing muscle strength and size. Yet in a review of published studies, Dr. Tanaka found that resistance training improved endurance in running and cycling. The effect occurred both in experienced athletes and in novices." 

Why this isn't 100% true: The smartest resistance training programs specifically created for running are not as Ms. Kolata says, with few repetitions and a goal of increasing muscle strength and size.  Rather, they are created with the knowledge that there is more than one muscle fiber type in the human body, and that all 3 should be stimulated in order to create a more powerful system that is not imbalanced.  For simplicity, we'll say there are 3 types of muscle fibers: Fast-twitch, medium-twitch and slow-twitch (technically known as Type IIb, Type IIa and Type I).  'Cross-training' (my definition: anything that will benefit the runner that doesn't include running) with resistance training workouts including movements that are not in the sagittal plane (as running is), that are geared towards the specificity of running, and including strength, mid-range endurance (or hypertrophy) and endurance programs, will most certainly improve performance (faster race times) and decrease injury risk (can we really measure this?).   Lifting weights is not ALWAYS few repetitions with a goal of increasing strength and size.  In fact, the best running programs will vary movement patterns and intensity (weight lifted) as per the specificity and requirement of the athlete or client.  In some phases, runners will need strength and power training, while in others, runners will need mid-range endurance (read: 10-12 reps) and endurance plus (15-25) depending on the movement pattern and workout. 
The problem with injury prevention?  We can't single-handedly isolate a workout program and its' association with lowering injury rates or improving performance.  HOWEVER, as renowned Physical Therapist Gray Cook says, the two biggest causes for injury are 1) the right side not agreeing with the left, or vice-versa) and 2) previous injury.  Training with an experienced Personal Trainer or Performance Coach who understands runners may face can help create personalized programs that can isolate specific weaknesses while integrating functional movements to reduce the disagreement between one side of the body and the other. 

3) The Claim "Dr. Willem van Mechelen, head of public and occupational health at VU University Medical Center in Amsterdam, looked at data on injuries in runners and tried to tease out the factors that were linked to them. And he concluded that the only way to prevent running injuries is not to run."
Why this isn't true: While Dr. Mechelen's abstract of running injuries and the meta-analysis provided awareness to the dangers of running, his statement never included what Ms Kolata stated:: The only way to prevent running injuries is not to run.  Instead, he stated:  "The prevention of sports injuries should focus on changes of behaviour by health education."  Unfortunately, Ms. Kolata jumped to conclusion and interpreted this falsely.

My recommendations:

The prevention of sports injuries, especially in running or cycling, is simple (not easy): running and cycling are repetitive injuries that place athletes at a high risk of injury (running because of repetition, cycling because of posture), so this statement should help clarify prevention 101: Train to run, don't run to train.  For example, a smarter (not HARDER) summary of Training to Run:

• As most coaches know, running is a poor choice of activities for calorie burning (~100 calories burnt per mile?  That's a lot of miles for not a lot of calories burned) 
• Training for running includes multiple planes, including lunges, deadlifts, squat variations, hip extensions, along with dynamic upper body pulls, pushes, and torso twists
• Training for running includes multiple running workouts, also featured previously in an article I did HERE, to stimulate multiple energy systems that are used during a race (for instance: hill workouts increase both the anaerobic ability of the runner, but also prepare the achilles for a larger stress than normal workouts on flat surfaces do). 
• Training for running includes an awareness that running is a KNEE-DOMINANT activity, so hip dominant movements are going to help increase glute contribution during stride (one of the glute medius' primary function during gait is to prevent the pelvis from dropping to the other side) and prevent other muscles' unprepared (and stressful) contribution to the movement pattern to continue running. 

Runner's left hip significantly lower than her right, indicating glute medius weakness

IN SUMMARY:  Running, although simple in description (one foot in front of the other with multiple stride lengths depending on the goal), is as complex a sport as any, and needs a complete understanding of the benefits, risks, training programs, and injury potential.  In this case, Ms. Kolata and Dr. Mechelen are close to helping runners perform better and decrease injury, but most may take away that they need to run more frequently and more distance and to avoid cross-training.  Both author and scientist are far from understanding the prescription to help runners with performance-enhancing activities  and decreasing injury risk in athletes.  The question remains: When it comes to training runners, why aren't successful runners and their trainers and coaches being questioned for their modalities and methods?  Relying on scientists in a lab setting, as proven above, is part of the equation, but putting together the minds of the scientist and practitioner will prove much more rewarding in the future.