Why can't runners cycle quickly?
To be honest, some of them can, but I wanted to get your attention with the title.
Another Ironman event done and dusted and numerous questions from competitors have lead to this blog post. It's a simple question, what's the difference in terms of fitness between running and cycling? Why doesn't running necessarily make you a great cyclist or vice versa? They are both endurance activities, both aerobic and both use your legs, but what's the difference?
Testing 1,2,3... The answer to some extent lies in the way we test cyclists and runners. People who visit us for VO2 testing will follow a set protocol, based on whether it's a run or bike test. The run test starts by running on a treadmill at a slow speed and every minute the speed gets faster until they either jump off or they are 'fired off' the back of the treadmill. As the treadmill gets quicker, they have to move their legs faster. Their 'cadence' is increased to allow them to stay on the treadmill, but the 'resistance' doesn't really change.
When you are running, the resistance is pretty constant, you have to lift the weight of your leg and push your body weight forwards, not a great deal changes as the treadmill gets faster, you just need to move more quickly. The cyling test is different. We start by asking people to cycle at 90 revolutions per minute and they must maintain that throughout the test (unlike running the cadence / leg speed does not change, it stays the same). Each minute we increase the resistance and it gets harder to turn the pedals, so unlike the run test, the resistance is increasing throughout the test. The test ends when they are no longer able to maintain the 90 revolutions per minute. In some ways, it's almost like doing a strength exercise such as the 'leg press' and as each minute passes, we add a little more weight until they can't keep going.
What can we draw from the above?
There is an element of strength involved in cycling that isn't required for running. You can call it strength or 'muscular endurance' (call it whatever you like), but the basic fact is that you have to work against high levels of resistance during cycling that don't apply to running.
What about gears and cadence?
Ok, so at this point you might be thinking there's a way round this. Rather than being strong, you can use an easier gear and pedal faster! Yes, to come extent you can and we see this a lot with runners who take up cycling, they prefer to spin easier gears rather than pushing big gears at lower cadences. However, there's only so far you can take this aproach. If you increase your cadence from 90 to 100 to go faster, what happens after that? Do you increase to 110? 120? 130!!??
Here's our basic observations about the problems often encountered by runners who take up cycling:
1. They lack the basic strength and struggle most frequently on flat courses, where the ability to push 'big gears' counts the most
2. This can generally be identified by a simple 5 second maximal sprint test, which results in a poor power output
3. Runners tend to favour spinning easier gears and may well favour a 'compact' or 'triple' chainset
4. On longer, gradual climbs, runners tend to come into their own and can perform relatively well (long gradual hills are the best courses and flat 'time trial' courses are the worst in terms of race performance)
5. Shorter / steeper hills on rolling courses may also be an issue as they lack the 'short term' power to maintain speed
6. When runners complete cycle testing sessions we commonly hear this: "My heart and lungs felt fine, it's just my legs, I couldn't turn the pedals, there was too much resistance"
7. It's more common in females than males and it's more common as age increases
8. When people enter Ironman triathlon, they make a presumption that riding long and slow to build endurance is the way forwards. After all, Ironman is all about endurance right? If the above article rings true for you, then riding long and slow will be a big mistake. Here's the simple truth. If you want to be an 'UBER' biker for non-drafting triathlon or cycle time trials, you really need to be able to generate a high power output and push big gears. Either that or you need to pick your courses very well to suit your strengths.
There's a lot of confusion and poor advice regarding the best cycling cadence, which has lead to confusion regarding the physical requirements and training for a fast bike time. People get told every day that you should 'spin a higher cadence' when cycling, which is misleading and leads to misunderstanding. In many cases, it makes people slower cyclists and fails to tackle their prime weakness.
On that bombshell... I'll leave it there and next week we'll discuss cycle cadence in more detail. If you found this article useful, don't be selfish, do the decent thing and share.
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