By: Alun Williams
Physiological assessments of elite and sub-elite cyclists have focussed on aerobic capacity (VO2max) as being the main determinant of success. Relatively little attention has been paid to the anaerobic capabilities of competitive road cyclists, in spite of the convincing argument that can be made for the importance of anaerobic function.
This becomes clear when you consider the role that explosive and sustained anaerobic energy production must play in attempts to break away from the pack, climb hills, and compete in sprints throughout and at the end of stages or races.
These sections of competitive racing rely on the maximum rate of energy production by the individual cyclist, when there is little or no assistance from team-mates in terms of avoiding wind resistance through stream-lining.
In fact, riding in a pack has been shown to reduce energy cost by as much as 39 per cent at a given speed when compared to riding alone. So it follows that the most successful cyclists may not necessarily be those with the greatest aerobic capacity, especially in a close race, but may well be those with better anaerobic power and sprinting ability.
Naturally, aerobic capacity is still extremely important but it may be anaerobic capability that decides the finishing order.
The Importance Of Interval Training
To determine precisely which were the important differences between sub-elite cyclists in categories 2-4 in the US (category 1 being elite), the research team of Tanaka et al at the University of Tennessee-Knoxville assessed both the maximal aerobic and anaerobic capabilities of 32 male and 6 female cyclists ('Aerobic and anaerobic power characteristics of competitive cyclists in the United States Cycling Federation', International Journal of Sports Medicine, 1993, vol. 14, no. 6, pp334-338).
Male Results
For the males, both aerobic and anaerobic performances seemed consistently higher as the standard became higher, suggesting a dual importance of both forms of energy production in achieving success.
VO2max values ranged from 4.5-5 l.min-1, or expressed another way 63-70 ml.kg-1.min-1, which agreed with other previous research.
Surprisingly, anaerobic performance was even higher than has been observed previously in power athletes such as gymnasts and wrestlers, although this may be partly a reflection of the cyclists' familiarity with the testing mode in all these studies - cycling itself.
Female Results
The results for the females could not be used to discriminate between standards because of the small sample size, although high values were still observed for both aerobic (3.4 l.min-1, 52 ml. kg-1.min-1) and anaerobic measures, displaying the same balanced physiological development.
Overall Conclusion
The researchers suggested that the years of strenuous interval training that the subjects had endured, especially the higher category competitors, had in fact served to increase both aerobic and anaerobic function - each of these has previously been shown to be affected positively during relatively short-term training programmes.
Thus the conclusions from this study include a large emphasis being placed on the importance of interval training for competitive cyclists. A controversy still exists about how well each of the two energy systems can be developed simultan-eously, without a sacrifice having to be made in favour of one or the other.
VO2max & Body Fat
A unique cycling event is the 4000m individual pursuit, where a competitor from a stationary start must propel himself as fast as possible over the specified distance using a fixed gear. At international level, competition times are around 4.5 minutes, rising to 6 minutes and over at sub-elite levels. At elite level it can compare quite nicely with middle-distance running with its similar demands, and is generally accepted to have an anaerobic/anaerobic energy requirement of 80%/20%..
Craig et al used this event to assess 18 exper-ienced male cyclists ('Aerobic and anaerobic indices contributing to track endurance cycling performance', European Journal of Applied Physiology, 1993, vol. 67, pp150-158). The purpose of the study was to supply numerous measures of the cyclists' body types and physiological characteristics, and to use this data to determine mathematically the factors that most contribute to success..
Study Results
Using relatively non-invasive methods, the two most important factors were found to be VO2max and body fat.
Even though, unlike running, there is no need to move it vertically against gravity, unnecessary body fat in cyclists still has a detrimental effect on three counts: an increased energy cost of acceleration at the start of the race, increased rolling resistance of the wheels on the floor, and increased frontal area of the cyclist - and thus increased air resistance.
Of these, the increased air resistance is the most important - 5 kg of extra weight add about 4 seconds to race time due to this factor alone.
Estimating Individual Pursuit Time
For those with access to accurate equipment, if you can measure your VO2max in l.min-1 and mass of fat in kg (can be calculated from body weight and percent fat), the equation for estimating 4000m individual pursuit time is: time in seconds = 441.2 + (4.316 x fat mass) - (25.94 x VO2max).
