Lactate threshold is a measure of how well our body can process lactate acid. Therefore, a rider that can put out a lot of power for a long time – for example, Tony Martin or Bradley Wiggins – will have a very high lactate threshold.

For efforts of ten minutes or longer, lactate threshold is the physiological factor that will determine how much power a rider can put out. The higher a rider’s lactate threshold, the more power they can sustain.

As I’ve discussed already, when you are riding hard you are recruiting your type II (fast twitch) fibres and this produces lactate. At the same time, your type I (slow twitch) fibres are busy processing that lactate. Lactate threshold is the point where your slow twitch fibres reach capacity – more lactate is being produced than what your muscles can process – and the lactate acid gets sent off in your blood to be processed elsewhere in your body.

The amount of lactate acid being transferred away from your muscles and into your blood is what is measured when we talk about blood lactate concentration. This is what is being measured in the small prick of blood taken during a lab test for those of you lucky (or unlucky) enough to have done one.

There has been a lot of discussion among sports scientists about at what level lactate threshold should be set but for ease it can be described as the maximum amount of power your can push with a blood lactate level of approximately 4mmol/litre of blood.

This all sounds very ‘coachy’ and, to be honest, it is. 4mmol/liter is seen as the maximum level of lactate in your blood that you can sustain without blowing up. Ride any harder and your blood lactate will increase exponentially and the effort will become unsustainable.

What does that mean out on the road? Essentially, lactate threshold is how hard you can ride for a prolonged period of time. The more lactate your muscles can process, the less is being passed into your blood and you’ll be able to ride harder, for longer. Sounds good, right?

Lactate threshold varies from ride to rider but ultimately it’s a key figure in determining riding your riding intensity. The good news is that it can be improved, too, but how can you determine your lactate threshold and use it to inform your training and racing?