Base Training for Cyclocross with Helen Wyman
We have all heard of base training and can see the importance for long road events where riders are spending hours in the saddle but why is base training important for a cross rider when races are between 40-50mins?
Base training is the name given to the training that teaches your body to utilize oxygen as efficiently as possible. It also conditions the body to deal with a certain training load. This means that later on in the summer when Helen increases the intensity in the run up to the cross season she will be able to complete back-to-back intense sessions.
Before we dive more specifically into the benefits, lets firstly look at what a typical base training ride looks like.
Here is a typical base training ride Helen did in her training base near Limoux in the Aude region of France. You can see that despite the amount of climbing on the ride Helen kept her power output relatively constant for the vast majority of the ride. It is important to note she did this on both the climbs and the descents!
The bands on the graph represent Helen’s training zones. The second band from the bottom is zone 2 – this is the zone that she uses to build her aerobic base
We can see her power distribution in this graph.
As you can see the majority of time was spent in zone 2 – roughly 150 minutes in total. The amount of time in zone 1 might be surprising however this is normal for a ride where there is so much descending, the roads around Limoux provide some magnificent descents – the time in zone 1 here is mainly where she has had to come off the power to take a sweeping bend. We can see this more clearly in the next graph.
In this graph we can see that a large proportion of the time that Helen appeared to be in zone 1 was actually 0-5w. This is as aforementioned when she is cornering or coasting. In the above graph you can see a nice grouping of the power data, this shows a nice consistent power output when she is on the pedals. This maximizes her time spent in zone 2 and therefore gets the most aerobic benefit from the ride.
So now we have seen how Helen executes a base training ride lets look at why. The graph below shows Helen’s peak power outputs compared with time. I have also included where her Functional Threshold Power (FTP) on the graph.
Any power output is a combination of aerobic (with sufficient oxygen present) and anaerobic (insufficient oxygen present) power production. The Functional Threshold Power (FTP) represents the maximal aerobic power output Helen can sustain – the higher an athlete’s ability to process oxygen the higher their FTP power.
Another way of thinking about FTP power is to consider lactate threshold. FTP power is the power output at Helen’s highest sustainable lactate acid blood concentration.
Contrary to popular belief, lactic acid isn’t the nasty stuff that makes your legs burn at the top of a climb: lactic acid is actually a fuel. It is created in the chemical reaction going on in your muscles when they are burning oxygen to produce energy.
Within muscle cells are mitochondria and these are the power stations of your body. It is within these mitochondria that lactic acid is burnt and energy is produced. When the mitochondria in the muscles reach their capacity in terms of how much lactic acid they can process, the additional lactic acid goes into your blood stream to be dealt with elsewhere in the body – leading to an increase in blood lactate. When base training correctly, the level of lactic acid in your blood isn’t elevated. That means that the mitochondria in your muscles are able to process all of the lactic acid being produced and don’t need to pass it on into the blood stream for processing elsewhere.
By riding at base intensity Helen is giving her mitochondria a workout, teaching them to process lactic acid in the presence of oxygen.
Returning to the graph we can see that anything below the ftp line represents aerobic capacity – using oxygen to produce power whereas anything above the line represents a combination of aerobic and anaerobic capacity (we call the anaerobic capacity Functional Reserve Capacity – FRC)
The idea of base training is to improve Helen’s aerobic capacity – the amount of oxygen she can utilize and how much power she can generate with that oxygen. Doing this in conjunction with threshold training will increase her FTP. Because any power output above FTP power is a combination of aerobic and anaerobic capacity then any improvements in FTP have a spin off in terms of increased anaerobic power outputs as well.
But how does this all apply to Cyclocross?
Well firstly any increase in FTP power means Helen will be able to sustain a higher average number watts for the 40-50 min race. However having a greater aerobic capacity will also help Helen recover quicker from the short sharp repeated efforts of a cyclocross race.
When your mitochondria are processing the lactic acid they are actually recreating ATP molecules. ATP molecules are what the body uses to pass energy around the body – think of them as small rechargeable batteries. These batteries power your muscles to move creating the watts you are putting through the pedals.
There are actually 3 ways to recharge these batteries – phosphocreatine system, lactic system and the aerobic system. The phosphocreatine and the lactic system both take place without oxygen and are therefore anaerobic energy systems – these systems both have limited capacity. The aerobic system is the most efficient way to recharge your ATP supplies and will supply ATP in a continuous fashion.
Now think of FRC as the amount of ATP molecules you can recharge without oxygen – this happens through the phosphocreatine and lactic systems. FRC is therefore limited.
Your phosphocreatine and lactic systems are very good at recharging a lot of ATP molecules very quickly, this means that these systems are used by your body when you need to produce a lot of power very quickly – such as in a sprint. However they run out very quickly. Once they run out they need to be re-charged.
The aerobic system can produce a very high amount of ATP molecules but it does this at a much slower rate. This is why you can start an effort with a sprint but then need to settle down to a much slower pace.
The more efficient your aerobic system the more energy it produces in a given time. This energy is used to recharge the anaerobic system or FRC.
The more efficient the aerobic system the quicker it can re-charge the anaerobic system.
In cyclocross Helen will sprint, coast, sprint, coast, sprint coast etc. In the times she is coasting her aerobic system is busy working away at recharging her FRC ready for the next sprint! This is why heart rate remains high even in the sections she isn’t pedaling. The more efficient Helen’s aerobic system the more she can re-charge her FRC therefore the harder she can sprint out of each corner and then faster she can go around a cross course!
If we go right back to the beginning we asked why it was important as a cyclocross rider to do long endurance base rides? These rides are designed to make the aerobic system as efficient as possible and therefore Helen can recover faster from all the small hard efforts meaning ultimately she is going faster!
Fig 1, Power graph from a zone 2 training ride
Fig 2, Helen's power output by zone during the training ride
Fig 4, Helen's Peak Power Output Graph with FTP marked
Fig 5, Helen's Peak Power Output Graph with Aerobic and FRC Capacity marked
Fig 3, Helen's power output split into 5w increments