David Joyce's blog: Track Cycling: Testing tactics, techniques and nerve...
Welcome once again to the Olympics! A few days ago, one of my most favourite sports commenced: track cycling. The longer events are a test of tactics, technique and nerve whilst the sprints are just like power lifting on wheels.
Given that the sprint events last for between 40 and 50 seconds, the athletes rely heavily on the anaerobic energy system in order power around the velodrome. The anaerobic energy system enables the body to generate ATP (the currency of muscle contraction) for muscle energy metabolism without oxygen. The ATP-Phospho-creatine system provides powerful, short duration bursts of energy of up to about 10 seconds, while the anaerobic glycolytic system is the primary energy producer for expenditures of energy lasting up to about 120 seconds.
"The muscular power displayed in the shorter track cycling events will come as a result of both aerobic and anaerobic metabolism"
Clearly therefore, the sprints rely to an enormous extent on the anaerobic energy system but many people seem to be under the misapprehension that energy provision is a discreetly demarcated process whereby some sports use one type of metabolism and other sports use a different one. The reality is, though, that whilst a short duration, maximal intensity event such as individual sprint in track cycling will bias the anaerobic system of energy provision, energy metabolism represents a continuum of contributions from the various methods of providing ATP to the working muscles, working in parallel rather than in series / step-wise process.
As such, it is folly to assume that even an event lasting only 40-odd seconds does not have a contribution from aerobic metabolism, even if it is labelled an anaerobic sport. The aerobic system is highly responsive to the demands of ‘anaerobic exercise’ and it has been reported that it provides around 20% of the energy provided for the completion of a 30s maximal cycling challenge such as we see in the Wingate Anaerobic Test, with its importance increasing steadily as the test progresses with even 35% contribution reported in the final 5s of the test. Indeed, VO2 during the final 5 second segment of a Wingate Test has been shown to be 93% of VO2max, further underlying the rapid response nature of aerobic metabolism.
Accordingly, the muscular power displayed in the shorter track cycling events will come as a result of both aerobic and anaerobic metabolism.
They need to be immensely powerful to wind the heavily geared bike around the track but they need to minimise the decay in pedal stroke power that comes with an inability to continually provide the muscles with a ready source of working fuel. This is why the track cyclists train not only the anaerobic system but the aerobic system as well.
I have worked closely with cycling physiologists over a long period of time and they are always amongst the most clever people in any sports institute. They need to be able to work with the coaches to prescribe the right amount of aerobic training without interfering with the strength process. Clearly, riding a bike at the Olympics is not as easy as riding a bike!
Stay robust, amigos!
Sports Medicine and Performance Consultant for Team China leading up to the London Olympics. Holds Masters degrees in both Sports Physiotherapy and Exercise Science and lectures on the MSc in Sports Physio course at the University of Bath and on the MSc in S+C at Edith Cowan University.