The 2015 Regionals finally exposed running as a tested modality in the qualifying stages of the CrossFit Games series. Though I certainly heard good runners complain that “the run didn't matter” for the chipper event (which I agree with to some degree), athletes who were not exposed to running volume in their training program leading into Regionals likely had to deal with greater fatigue levels throughout the event and longer recovery times after the event. Despite this, running was still just a small component of an athlete’s overall finish at Regionals. If this is the case then why have we seen top athletes in our sport flocking to endurance coaches to receive running programming? Running can be an effective tool for improving both cardiovascular as well as aerobic capacity when implemented correctly in a training design, however just following the same endurance program as Camille, Rich, or Matt will not necessarily guarantee the same results. The drawback to increased volumes of running is the potential to stunt strength development (this has been documented extensively in strength training research) and the elevated risk for lower-body injuries from repeated impact. When implementing running into an athlete’s training design coaches should not just apply protocols from elite endurance athletics for reasons we will explore further.
How is running different?
Running places a greater physiological demand on the body than most other traditional cyclical modalities (cycling, swimming, rowing). The reasons for this are many and differ for each modality. For example while rowing does recruit a large proportion of our muscle mass (possibly more than running through the trunk-stabilization required for running at any speed is significant) the overall tempo/cycle-rate and built in recovery phase in each stroke prevents athletes from generating the same physiological demand from rowing as is possible from running. It is common for athletes with amazing aerobic and cardiovascular development on non-weight bearing cyclical modalities to struggle with running and this is certainly a factor.
Another important point to take into consideration is that running is the only commonly tested cyclical modality in CF where the body-weight of the athlete determines the power-output requirements for matching performance metrics. Continuing our rowing example, regardless of bodyweight if you hold 300W for 500m you will be 1:40. Running on the other hand requires differing power outputs for athletes of differing body weights. For example the wattage required for a 200# athlete to run 400m in 1:15 is significantly higher than the wattage required for a 150# athlete to do the same. When comparing running testing results or determining training volumes for athletes of different body-masses this is critical. In other words running prescriptions must be individualized to a greater degree than rowing or stationary cycling.
Additionally, running is the only one of the aforementioned cyclical modalities that induces significant levels of muscular damage. Part of this is due to the impact of repeated food-strikes and the associated eccentric contractions involved in decelerating the body/limbs during the foot-strike and swing phases of running. Obviously efficient runners have developed their mechanics to minimize this damage relative to novices and are more adapted to this stress, however it is apparent at all levels of athletes utilizing running as a training tool or sport. Heavier athletes will have even greater levels of training stress from matched running sessions when compared with lighter athletes (this HAS to be taken into account when designing training for athletes in CrossFit).
As a result of the increased muscular damage and eccentric stress - recovery times for running sessions is longer when compared to matched volume/intensity rowing, cycling, or swimming sessions. This is particularly true from a nervous system standpoint. It has been my experience that novice runners will see far more decrements in coordination, speed, and absolute strength from a high-intensity running interval session than a similar rowing or assault bike training session. It is critical therefore to plan a training cycle or week properly to allow sufficient recovery time around running sessions particularly for heavier or novice runners.
Running as stand-alone endurance training
Running as a training modality can be used effectively both within mixed-modal conditioning to drive the anaerobic/aerobic or cardiovascular stimulus (depending on length/intensity of the prescription) as well as used as a stand-alone training modality to target specific training adaptations. Running is one of the few training modalities that is effective for developing energy-production across all energy-systems and intensity levels. Intensity can be modulated from extremely high-power maximal-effort sprinting to easy recovery jogging; making running a versatile training tool for CF athletes.
With that said it is important to keep in mind the increased tissue stress and recovery times that we discussed previously. When analyzing the training programs of elite endurance runners versus elite cyclists, rowers, and swimmers it quickly becomes apparent that the total training volume completed is significantly lower both from an adjusted millage as well as a total training hours standpoint. Training volume should not be matched 1:1 between training modalities, rather generally we see elite runners completing about 60-75% of the total training duration of other elite cyclical sport athletes. This is generally a good starting point when first implementing a stand-alone running program for novice runners in the sport.
Another important consideration for coaches and athletes in CF to take into account is that the training protocols utilized by elite level endurance athletes are likely far too high in overall volume for even top level CF athletes. A large part of this is a function of body-weight. Typical male endurance runners are 30-50# lighter than typical elite-level male CF athletes. The overall mechanical stress incurred by carrying an additional 30-50# during a running session cannot be ignored when developing optimal training programs for CF athletes.
*Note: in light of the addition of a running sprint at the completion of each event at the 2015 Regionals, running speed under fatigue may become a more important element at the highest levels of the sport. Developing this type of straight line speed requires very different training protocols than running for endurance development.
Conflicting training adaptations
The conflicting adaptations that occur with concurrent strength and endurance training are well documented. Furthermore studies that have compared the deleterious effects of running vs cycling on strength adaptations consistently demonstrate that running creates more “interference” to the development of maximal strength than cycling. This is generally attributed to the increased mechanical stress and subsequent CNS demand of running endurance training versus lower-impact cyclical modalities. This is not to say that athletes cannot get stronger while implementing a running program, but rather that most athletes will see slower strength adaptations when running is implemented in the program without proper planning. There are obvious exceptions to this rule: Jason Kalhipa and Rich Froning both come to mind as athletes who have been able to maintain and even improve their strength metrics while implementing structured stand-alone running endurance programs. They are clearly exceptions and should not be bandied about as “proof” that combined training is the MOST effective way to target absolute strength adaptations.
To simplify this - high-volumes of higher-intensity running need to be carefully placed throughout the training week if the goal of the athlete’s training cycle is to maximize strength. Alternatively if strength development is the priority, coaches could consider relying on lower-impact cyclical modalities at lower-intensities thus minimizing the conflicting influence of endurance training on strength progression.
Depending on the athletes experience and running mechanics, they should follow a simple progression to begin implementing running as a standalone training tool. Just like in any other training modality, athletes should first develop mechanics and consistency before adding volume and intensity. This can be accomplished by using shorter intervals with extended rest periods building into longer intervals with shorter rest periods. This allows athletes tissues (think muscles/tendons/ligaments) to adapt progressively to the demands of running while they develop the local muscular endurance needed to run for longer durations.
In my experience supplemental running is best used during cycles where the goal is to improve an athlete's lactate threshold or when they need to improve the interaction of their anaerobic and aerobic systems. For many athletes this means utilizing running extensively during the cycle preceding their peaking cycle. I have also found that starting a cycle with stand-alone running sessions and progressing into mixed running + basic conditioning session during these cycles allows athletes to experience more carryover from their running endurance training to their sport-specific endurance.
Obviously this process takes some foresight to obtain optimal results and may require starting athletes on a running progression during the off-season in order to have them ready to tackle the endurance program later in the year. This also requires coaches to perform a needs-analysis to determine if the time needed to develop running proficiency could be better used in other training areas (i.e. developing absolute strength, gymnastics mechanics, etc).
Running can be an incredible tool for developing speed, power, and endurance, however it cannot be implemented haphazardly. Just adding a track day and a long-run to an athlete’s training program is not necessarily an ideal way to structure an endurance program. There are many things that need to be taken into account including the goals of the current training cycle, the athlete’s exposure to running and body-mass, as well as determining if other cyclical modalities or mixed-modal training may be more suited for the needs of the athlete.