The Sweet Spot
What is the Sweetspot in training?
After my article on base training a number of people got in touch to ask if it would simply be more effective to ride at ‘sweetspot’ to maximise training benefit if the amount of time on the bike is limited.
But while sweetspot is an important tool in any rider’s training armoury, the answer, unfortunately, the answer is not simple.
If we refer back to the last article I wrote on training zones, then ‘sweetspot’ intensity is between the upper end of zone three and lower end of zone four – or 88-93 per cent of FTP power or threshold heart rate, and between 75-85 per cent of maximum heart rate. Refer back to that article to find out how to find your FTP of maximum heart rate.
The idea of sweetspot training is to get the most training value for your time on the bike. Sweetspot training therefore balances the exercise intensity and volume of training – hence the term ‘sweetspot’.
The training effect you get from a session is a combination of how hard and how long you exercise for. The idea of sweetspot is that by riding at the maximum intensity that you can sustain for the period of your training session you get the maximum training benefit.
Sweetspot training is a very useful training intensity as it’s a great tool to increase your power at anaerobic (lactate) threshold.
Remember, anaerobic threshold is your functional threshold power (FTP) if you use a power meter, or the maximum heart rate you can sustain for one hour. It’s at this point that the amount of lactate in the blood is elevated but still under control. So, sweetspot training will increase the amount of lactic acid that can be processed as fuel in your muscles and, therefore, your anaerobic threshold should increase.
But what does this mean in the real world? Well, the power or the speed you can ride for between 15 and 45 minutes will improve. Therefore, sweetspot training is perfect if you are targeting 10-mile time trials or long alpine climbs.
An additional spin-off is that riding at intensities lower than lactate threshold should also start to feel easier. For example, if your anaerobic threshold is 250 watts then when riding along on your local club run at 200 watts you are exercising at 80 per cent of your anaerobic threshold. However, if after a period of sweetspot training you have increased your anaerobic threshold to 275w, then riding in the same group requires only 73 per cent of your anaerobic power. Not only will to feel easier but it will also be more sustainable
Sounds great, right? Well, it’s not all ‘sweet’…
Sweetspot training is often seen as a magic bullet to success on the bike.
In fact, what it should be considered, just as is the case when riding at other intensities, is a piece of the puzzle that can be used to improve your fitness and form on the bike.
Sweetspot has the affect of raising your anaerobic threshold, however it won’t necessarily increase you performance over short periods. When training at sweetspot intensity you could actually be making yourself slower…
Six things you need to know about…
Most riders have heard of the concept of slow (type I) and fast (type II) twitch muscle fibres, however it isn’t quite as simple as that.
Fast twitch fibres can be split into two groups, type IIa and type IIb. Type IIa fibres are an intermediary between fast and slow twitch fibers. They produce a lot of power but also produce a lot of lactic acid. They can use both aerobic and anaerobic metabolism – that is to say they can push the pedals with or without sufficient oxygen. However, the period of time they can produce power without sufficient oxygen is limited. Type IIa fibres are used (alongside slow twitch fibres) when riding up to and around anaerobic threshold. In contrast, type IIb fibres are pure fast twitch fibres and are used to create short bursts of movement.
However, your muscle fibres aren’t set in stone and can be changed from one type to another over time.
Training at sweetspot puts a lot of emphasis on type I and type IIa fibres. Your body responds as a result and pure fast twitch (type IIb) fibres get converted into type IIa fibres. This means that if you do too much training at sweetspot then you will loose the ability to put out short bursts of power – this explains why you never see a time trialist winning a bunch sprint in the Tour and you never see a sprinter winning a long time trial! Time trialists have a high proportion of type I and type IIa fibres, whereas sprinters will have a higher percentage of type IIb fibres.
So sweetspot training isn’t necessarily the fast track to fitness that some riders believe it is and it’s important to still have a solid base to make the most of sweetspot sessions. Here’s why…
Back to base...
If you want to build fitness quickly, then why shouldn’t you skip base training and get stuck straight into sweetspot sessions?
Well, the answer is that you want to retain your type IIb muscle fibres as quickly as possible and base training will help you do that.
Base and sweetspot training give similar benefits and while sweetspot may get you there slightly quicker, there are downsides in that can lose your explosive power. This can make the difference between winning and losing at the end of a race.
Don’t get me wrong, sweetspot is a very important training tool. However, as I mentioned earlier, it is no magic bullet and needs to be used alongside other elements of training.
The amount of sweetspot you need to incorporate into your training plan depends on what type of rider you are and where you want to improve. If, for example, you are aiming to ride criteriums which include lots of short explosive efforts then sweetspot training should be limited, however if you are aiming for longer time trials and riding in the Alps then sweetspot training is exactly the type of training you need to do.
When to include sweetspot sessions
Sweetspot training has many benefits but it is also quite fatiguing, therefore if you jump straight into sweetspot sessions you will not only run this risk of being less explosive but you will also find yourself getting tired pretty quickly.
Six things you need to know about…
Over a prolonged period of time this may actually reduce the amount of time you spend training. For example, if you need two days to properly recover after each sweetspot session then you may only get three quality sessions in a week, whereas if you train at a base intensity then you should be able to complete two or three sessions back-to-back and this could mean that you actually complete five good sessions during a week, thus actually giving your body more of a training stimulus.
As discussed in my article on base training, one of the key benefits of building your base at a low intensity is that it prepares your body to handle a certain training load. Therefore, I would always recommend people start with base training and once that is in place then you can up the intensity, bring the hours down and start to introduce sweetspot sessions into your training.
When you’re ready to include some sweetspot training into your schedule, here’s an example of one of my favourite sessions.
A typical sweetspot session
2 x 20mins at sweetspot + bursts – total riding time 1h30mins
20 minutes warm-up – a slow progression from zone one, through zone two, with the last five minutes in zone three.
Five minutes easy (zone one – two)
2 x 20mins sweetspot efforts (upper zone three – lower zone four)
During these efforts, every two minutes you need to incorporate a ten-second out of the saddle burst. This isn’t a sprint! A burst means clicking down two or three gears and pushing on out of the saddle (for those training with a power meter 120-150 per cent FTP). Once the burst is finished settle straight back down into the sweetspot effort.
15 minutes between efforts (zone two)
Ten minutes cool down (nice and easy, zone one)
What are the benefits of this session?
This session includes both elements of sweetspot and base training. Keeping the sweetspot efforts short with a break in the middle will mean that you can hit the correct intensity for an entire forty minutes within a session.
If you tried to do forty minutes in one go then chances are that by the end of the effort you will be struggling to hold the intensity high enough to hit sweetspot. The bursts in this session are designed to also give an element of training to your type IIb fibres.
Doing this means that you are reminding your body that you do still need them and they are less likely to be converted to type IIa fibres.