Since the 2008 Beijing Olympics, the GB cycling team has been unstoppable.

Dave Brailsford is the man credited with transforming a relatively minor sport in Britain into one of the most successful team's the country has ever seen. 

Under his leadership, British cycling saw its first and second Tour de France winners in the form of Bradley Wiggins and Chris Froome in 2012 and 2013, with Froome then replicating this success in 2015, 2016 and 2017. 

That's not to mention Team GB's astounding 32 Olympic medals from Beijing, London and Rio, including 20 golds. 

In a sport previously marred by doping, glory could at times seem out of reach for clean athletes. 

However, this changed when Brailsford implemented the marginal gains theory, making tiny changes to beat opponents. 

As Team GB prepares to dominate in the velodrome once again, you may hear commentators and pundits discuss the marginal gains approach.

Here's everything you need to know...

What is the marginal gains theory in cycling? 

The marginal gains theory focusses on making tiny improvements, which then accumulate to make much bigger improvements. 

It's a theory that can be applied across a range of disciplines, but sport, and particularly cycling, is perhaps the most famous example of the success it can bring. 

When Dave Brailsford became performance director of British cycling in 2003, he introduced the marginal gains concept to the programme. 

He believed that if the team could make 1% improvements in different aspects of cycling, athletes could significantly improve results. 

These improvements incorporated every part of the athletes lives, from physical fitness and race tactics to nutrition and even sleep. 

The team viewed the sport from every possible angle: cycling in a wind tunnel showed bikes were not sufficiently aerodynamic; examining the mechanic truck's floor found that accumulating dust was harming the bike's efficiency. 

Once these weaknesses had been identified, the team considered what changes could be made and what gains, however marginal, could be achieved. 

The changes weren't directly focussed on the equipment however. 

Years before Covid, British cyclists were using antibacterial hand gel to reduce chance of infections.

Hypoallergenic bedding and mattresses travelled with the team, to ensure athletes maintained the same level of sleep from destination to destination, with road races involving a lot of travel

Warm ups and cool downs became more focussed and specific, something which at first made the British team a laughing stock amongst competitors, before they too realised the benefits of the gains. 

Everyone in the team, from the coaches to the bus driver, was involved in the process and kept informed about what the athletes were trying to achieve. 

Once again, however marginal the advantage, it meant that everyone was aligned in trying to achieve the ultimate goal. 

As one team member noted during a documentary in the lead up to 2012, these minute changes alone would make no difference, but when gathered together the advantages can be significant. 

This was echoed by Brailsford, who, after the 2012 Olympics, spoke about the marginal gains approach: "The whole principle came from the idea that if you broke down everything you could think of that goes into riding a bike, and then improved it by 1%, you will get a significant increase when you put them all together.

"There's fitness and conditioning, of course, but there are other things that might seem on the periphery, like sleeping in the right position, having the same pillow when you are away and training in different places.

"Do you really know how to clean your hands? Without leaving the bits between your fingers?

"If you do things like that properly, you will get ill a little bit less.

"They're tiny things but if you clump them together it makes a big difference."