Why does it seem like cycling and running are not good cross training companions when one is trying to excel at running?
The value of cycling with running for cross training is dependent on several factors, the most important being the purpose behind the cross training. To improve running specifically, there are several areas in which cycling will have limited value.
- Exercise technique. Running technique is obviously different to cycling technique. Where cycling has several mechanical-based constraints that have to be incorporated, running involves the manipulation of stride length and stride frequency along with the reciprocal arm pattern required for the upper body. With this in mind, the basic principal of practice, practice, practice is appropriate. When cycling, you are using time that could otherwise be allocated to improving running technique and most importantly efficiency. For those considering the mental fortitude that can be gained by improving training time via use of cross training, also consider that it is hard to incorporate mental running techniques (e.g., concentrating on breathing patterns, changing stride and cadence in relation to terrain, concentrating on arm lines etc) when cycling.
- Neuro-Motor Patterning. Along with exercise technique comes the neurological component of motor patterning. While cycling and running both use similar muscles (lower legs in particular), the muscle strength ratios, ranges of motion and timing are unique to each discipline, and numerous research studies have shown a poor transfer effect (although to be fair, a few have found gains).
- Impact. Running obviously releases higher impact forces through the body than cycling. One key area that I am planning to investigate over the next several years is the impact of impact (no pun intended) on breathing. Do we naturally time breathing in anticipation of heel strike in running (i.e., local application - tightening the diaphragm to increase hoop tension or global application - increasing trunk rigidity using the global abdominal muscle group and through Newton’s laws return energy to the lower legs)?
- Experience. Of course, another key consideration is the experience/fitness level of the client. If unfit, the initial cardio respiratory benefits from the cross training could transfer to running. Likewise, if the client has a limited running experience level, improvements in technique and hence efficiency could allow improvements in run time, regardless of the cross nature of the training.
While a cross training approach comprising of cycling and running may not be the most appropriate combination for improving running times, there are some advantages of this mix.
- Fat loss. In regards to fat loss, when appropriate training protocols have been used, cycling has been shown to be as effective as walking and running in altering body composition.
- Variety. For those who do a high running work load, cross training can provide variety and help prevent pattern overload and mental overtraining (boredom and "staleness") while maintaining some transferable cardio respiratory fitness.
- Injury management. The cross training approach provides a means of cardiovascular training without the impact. Therefore, for those with impact stress-related injuries (e.g., anterior/postero-lateral shin soreness), a running/cycling cross training session can allow some continuation of run training while still applying longer periods of cardio vascular stress.
- Sport specificity. Then again, there are the sports that encompass both cycling and running disciplines (e.g., triathlons). As such, athletes training for these sports often complete cross training styled sessions. While the individual disciplines are often technically perfected separately, overload and transitions ("brick" sessions) are often trained using cross training formats.
In conclusion, while there is a place for running/cycling cross training sessions, this combination may have limited transferability to the improvement in run times due to the loss of specificity (most notably, neuro-motor patterning and technical training).