In road races such as the Tour de France, cyclists tend to ride the flat stages in groups known as peletons, which are bunched packs of riders, or echelons, where riders form a diagonal line across the width of the road. Drafting is the raison d'etre for these groupings.
A Monash University study found that overcoming drag accounts for around 90 per cent of energy expended by a cyclist.
The same study also found that riders in an optimal drafting position experience up to a 49 per cent reduction in drag, meaning they expend significantly less energy. In a gruelling long-distance race such as the Tour de France, that energy conservation is vital.
The closer you are to the lead rider, the better the effect. Dr Lisa Jardine-Wright, a physicist from Cambridge University, told the BBC the benefit of the low-pressure pocket can be lost if you're more than a bike length away from the leader.
Maths explains why drafting is so important. Resistance, said Jardine-Wright, is proportional to velocity squared. Therefore, if you double your speed, the resistance you encounter is multiplied by four. That's a problem if you're trying to go fast. And the faster you go, the more power you require. Because power corresponds to velocity cubed, a cyclist needs to put in eight times more effort to double his speed.
This tends to explain why professional riders so readily risk limb, if not life, to get into good drafting positions. The alternative is hard slog and almost certain defeat.
For road cycling purists, the alchemy of drafting is at the very core of the sport, in the same way the swinging ball is essential to cricket.
But it's worth noting that not all riders can avail themselves of it. Ironman rules, for instance, strictly forbid drafting. And time trialists such as Linda Villumsen are consigned to deal with the brutal physics of wind alone.
So don't despair when you're inching forward into a nasty easterly on the way home from work tomorrow - at least you're in good company.
