Over the last number of years Power Meters have become an important part in 80% of the riders who ride the Tour de France every year. Most of these riders are the elite of cycling from around the world. That in itself is a clear indication that training with a power meter must offer some advantage over the previously used Hear Rate only system.
Power Meters have also changed the focus of some coaches to a more mechanical view of a riders pedal stroke rather than a performance view.
Lets look at increasing power. One of two things needs to happen,
1. Increase pedal speed (Revolutions per Minute)
2. Increase the pedal force (Torque)
If we have a rider super fit and at 120rpm their seems to be nothing left for that rider to do to increase speed other than if he/she increases pedal force. So if a rider is aerobically fit but lacks the necessary strength then he/she is out of the equation.
Neumann (2000) conducted a vast amount of biopsy studies on strength endurance athletes and found that the optimal relationship between fast and slow twitch muscle fibers was 1:3:1. This is the size ratio and not the percentage ratio.
When building this ratio it comes with detriment to the aerobic system. The increase in size of the fibers needs to be supported by the aerobic system. This is a challenge from an exercise prescription stance but good coaches can deal with this problem very easily. Also in increasing strength the riders find that their aerobic system has more to offer and previously hadn’t been training to it’s maximum.
It is also very important to prescribe strength building workouts based on torque values in order to achieve the correct adaptions. As we know the current power meters don’t display torque values so it is important that the coach transfer the correct torque values for the prescriptions by way of calculations. The rider will receive a power and cadence value which will be equal to a specific torque. 300w at 100rpm has a different value torque as opposed to 300w at 35rpm. Again a good coach will be able to prescribe this. This type of training can not be done on Heart Rate Only!
Low torques over longer durations increase muscular endurance while high torque values over short durations will increase strength.
Unfortunately in Ireland we do not have any mountains only a few hills. In order to achieve torques sufficiently high enough riders should be using a 55 or 56 chain ring with an 11/12 sprocket. This will generate the required torque for the adaptions to take place. Riders on the continent can easily generate these torque on long climbs of an hour or more at slow speeds and low cadences.
I’ve attached a study “Effects on the crank torque profile when changing pedaling cadence in level ground and uphill road cycling” just to highlight the difference between torque on flat roads compared to climbing” Journal of Biomechanics 38 (2005) 1003–1010
Despite the importance of uphill cycling performance during cycling competitions, there is very little research investigating uphill cycling, particularly concerning field studies. The lack of research is partly due to the difficulties in obtaining data in the field. The aim of this study was to analyse the crank torque in road cycling on level and uphill using different pedaling cadences in the seated position. Seven male cyclists performed four tests in the seated position (1) on level ground at 80 and 100 rpm, and (2) on uphill road cycling(9.25%grade)at60and80rpm.The cyclists exercised for 1 min at their maximal aerobic power. The bicycle was equipped with the SRM Training System (Schoberer, Germany) for the measurement of power output (W), torque (Nm), pedaling cadence (rpm), and cycling velocity (kmh1). The most important finding of this study indicated that at maximal aerobic power the crank torque profile (relationship between torque and crank angle) varied substantially according to the pedalling cadence and with a minor effect according to the terrain. At the same power out put and pedaling cadence (80rpm) the torque at a 45 degree crank angle tended (po0:06) to be higher (+26%) during uphill cycling compared to level cycling. During uphill cycling at 60 rpm the peak torque was increased by 42% compared with level ground cycling at 100 rpm.When the pedalling cadence was modified, most of the variations in the crank torque profile were localised in the power output sector (45d to 135d).
2004 Elsevier Ltd. All rights reserved.
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