Perfecting the aerobic / anaerobic dose
When an athlete performs any kind of endurance exercise, there will be energy contributions from both aerobic and anaerobic pathways. Most cyclists, runners and triathletes seem to know this and certainly know the feeling of being too long in a highly anaerobic state (in the RED). Each pathway has it's unique advantages for bike riders, aerobic metabolism is highly energy efficient, powering muscular activity for long periods of time, but unable to fuel the super high intensity efforts required for power climbs, sprinting etc. So this is where anaerobic metabolism has the edge, producing energy rapidly to fuel high level exertion, but of course there is a cost, which is the rapid onset of fatigue. Cyclists need both systems working well, but the cruel reality is that over-using either of these pathways will erode the other, so getting the balance or "dosing relationship" right is paramount for increasing endurance performance and building reliable consistent form.
A certain amount of muscular work requires a fixed amount of energy, so it stands to reason that the more energy supplied anaerobically, the less is contributed aerobically and vice versa. As in all aspects of physiology, the more one's system utilises a particular process, the better the body becomes at doing it. Conversely, should certain processes be under-utilised, the capacity for using these processes is eroded. The bottom line is that over-reliance on either of the two metabolic pathways, will negatively impact on the other.
This sounds simple enough but the process becomes far more complicated if you consider that athletes vary greatly in terms of which points on the intensity continuum they become anaerobically dominant. Some cyclists can remain highly aerobic VERY close to threshold (this means they have a very large zone two) whilst others become significantly anaerobic well below threshold. A big aerobic capacity also pushes the threshold point much closer to maximum, which is the holy grail for endurance cyclists.
Put simply, training zones cannot be accurately established using simple percentages of threshold / FTP and without defining training zones more precisely, it will be almost impossible to get the training dose right. The chart above shows an athlete with diminished aerobic capacity and a small zone two. Zone three represents a significant shift towards anaerobic metabolism and occurs at relatively low power / heart rate for this rider. Knowing this is critical for getting the training dose right and avoiding continual erosion of aerobic efficiency, a certain recipe for an over-training disaster.
There is no doubt that the most common mistake made in respect of training dose and the balance between aerobic / anaerobic load is an over-emphasis on anaerobic work. The notion of "go til you blow" will work for short periods, but has no future, in terms of building reliable, consistent form. The key is knowing your training zones and understanding that the most important attribute in developing good form (apart from being genetically blessed) is patience and control.
Get tested and don't just rely on predicting your zones through an FTP conversion, this error is the main reason that similar training plans produce vastly different outcomes for cyclists. Build power through understanding your body and it's capacity for adaptation.
Enjoy the Ride
The ScyclePro Team