It is now the time of year when season PB’s are probably behind us, unless of course you are building for the CX season. Many of you will have had a great season and improved many of your performance markers. Remember that FTP is just one performance marker and yet it is the one most obsessed about by amateur cyclists, and with good reason. Turning a bigger gear for longer periods of time will make your average speeds increase over many cycling disciplines.
But what if you are one of many people who have seen their FTP plateau over the past year or maybe even longer? The answer may not lie where you think it does.
Many of you will understand lactate threshold as an area of exercise intensity that roughly corresponds to FTP. Other terms used to confuse you include Maximum Lactate Steady State, Onset of Blood Lactate Accumulation or Anaerobic Threshold. Roughly, roughly, these all refer to the highest power output that can be sustained before a continual increase in muscle and blood lactate and hydrogen ions force you to stop.
Lactate has been given bad press over the years, often being labelled as lactic acid that builds in your legs and causes them to burn during high intensity or prolonged exercise. This is an incorrect characterisation as the burning sensation you get in your legs is caused by a buildup of hydrogen ions, which increases the PH in your muscles and blood and causes acidosis.
Lactate is produced by the body at all times, even at rest. Energy production is a continuum with both aerobic and anaerobic energy production in use at any given moment. The balance between the two systems is dependent on exercise intensity and an individual's physiology. Lactate is used by the body as fuel at higher intensities. The reason that exponential increases in lactate correlate to fatigue is due to the increase in hydrogen ions that are caused by increases in exercise intensity.
Key to improving lactate threshold(s) is to try and get the body to lower lactate production at any level of exercise intensity. This comes from training your body to aerobically oxidise fat to supply a greater percentage of your energy needs. Using more fat as fuel has again been described as a means to lose weight or spare glycogen reserves when maybe its greatest benefit is raising lactate threshold(s). By increasing fat utilisation and lowering carbohydrate usage at a given power, we can increase lactate threshold or FTP.
The quantity of lactate production depends on the level of exercise intensity at which carbohydrates become the dominant form of fuel. The harder we exercise, the more we burn carbohydrate and the more lactate we produce. Therefore, to reduce lactate production, it stands to reason that we have to train more aerobically to increase the aerobic capacity of our muscles through better mitochondrial oxidisation.
Therefore, from a training perspective, we need to encourage the body to improve mitochondria quantity, density and function to increase muscular oxidisation of fat as fuel.
As suggested above, there are two lactate thresholds. The one you all probably know about that corresponds to FTP is the second threshold, also known as LT2. This is the point where blood lactate starts to increase exponentially and is correlated with exercise fatigue and exhaustion.
The first lactate threshold is found at a much lower level of exercise intensity and is called LT1. This is the level that blood lactate starts to increase above observed baseline figures. The most reliable way to establish baseline LT1 and LT2 levels is by doing a stepped lactate test in an exercise performance laboratory. There are more ‘functional’ ways to estimate these levels, but for those that are serious about optimising the intensity of their training, we would highly recommend proper testing.
Training to improve the quantity and quality of mitochondria has been proven to be best executed at levels under LT1, so at an easy to moderate intensity for long periods of time. It is the duration of sessions and the overall training volume that is important here.
These adaptions in mitochondria are not improved by training at higher intensities.
These adaptions in mitochondria are not improved by training at higher intensities.
From a physiological perspective, easy intensity duration is a key part of improving as an endurance athlete and yet is an area that we see most omitted in training. Why? Because people are time crunched and have been seduced by the middle of the road sweet spot arguments. We have no objection to sweet spot training (Threshold Training in disguise, but more of that in another post!) but it is not for everyone and you will reach a point where no matter how much of it you do, you won’t get any better and your FTP will plateau.
No matter how hard you try, you can’t keep pushing FTP up by doing efforts where lactate is accumulating. Training at LT2 or FTP is about training the body to clear or transport lactate way from working muscles where it has become over saturated, to other areas of the body. Training at this higher intensity has nothing to do with lowering lactate production, and all about getting rid of it. Once you have trained enough to elicit most of your lactate clearance capabilities, you will find it hard to improve it anymore, and that could be the most likely cause of your FTP plateau.
You need to refocus your training to elicit a move of your whole lactate curve to the right. Delaying the point at which lactate starts to rise above baseline readings will improve LT1 and enable you to improve LT2.
Does this mean I will have to just ride long and slow?
Aerobic riding at levels of less than LT1 or approximately 75% FTP or 80% HRM should be a staple diet of every weekly training schedule. Duration here is key, but you can also add in some form of carbohydrate restriction if you are short of time (note that for some female athletes, this might not be a good protocol to follow). These rides at or below LT1 will encourage the oxidisation of fat as fuel and delay the point at which lactate starts to rise above baseline levels.
Once aerobic efficiency has plateaued, we then progress training to slightly higher levels of aerobic intensity.
In our experience, moderate and consistent levels of training at moderate levels of intensity will reap decent early gains in a ‘training career’. However, at some point those gains will cease to come and a different approach will be needed.
In addition to this easy to moderate intensity training, we also like to work on efforts at or slightly above LT2 before event or race specific considerations of training need to be taken into account. This focus of training is all about improving lactate clearance from the blood and muscles and reducing the acidosis effect of the accumulation of hydrogen ions. For the older athlete, these higher intensity efforts through the entire season helps to slow the outgoing tide of our aerobic capacity.
As is always the case, training should be specific to the individual. We believe that sweet-spot training is highly effective with athletes that have a small number of hours to train and have little history in structured training. Focusing your workouts in between LT1 and LT2 (often called the grey or dead zone) is effective in these cases, as it improves both aerobic and anaerobic fitness at the same time. In our experience, moderate and consistent levels of training at moderate levels of intensity will reap decent early gains in a ‘training career’. However, at some point, those gains will cease to come and a different approach will be needed.
From most of the people, we have seen a shortage of aerobic training is the most common cause of this stagnation, not a lack of effort!
Focusing your early season training at the two lactate thresholds is actually very time effective. One aerobic sub LT1 ride per week and 2 harder LT2 or above interval sessions can be enough depending on your training history and goals. If appropriate, adding in some carbohydrate restricted early morning sessions on the rollers or turbo can also help to encourage mitochondria biogenesis, making it a highly time effective strategy for some.
There is one common truth in all of training and that is if you stop improving, then you need to change something. If you have been following a classic pyramidal training plan for many years and have stopped improving, then maybe a more polarised approach is needed to specifically target the physiological change points on your lactate curve.
This is not a one size fits all cookie cutter approach, far from it. The balance of training intensity here is key given your training history and goals, and should be flexed in different proportions at different times of your season.
Whatever you have done or are doing, be it self coached or coached, then make sure you understand how your energy systems work, what you are trying to achieve and mix your training up. It will keep you fresh mentally and improve your chances of seeing more performance improvements.