World-class rowers have long "levers" (their arms and legs) so that they can make long strokes.

Male Olympians tend to be between 1.90m and 1.95m (6'3"-6'5") and females 1.80m-1.85m (5'11"-6'1").

Sir Steve Redgrave maintained his muscle mass through his career

They need to be strong so that they can apply a lot of force to the water on each of their strokes. The extra muscle power makes them heavy.

The average weight for a male world-class rower is 90-95kg (14st 2lb-15st). The women weigh in at 75-80kg (11st 11lb-12st 8lb).

And that's almost pure muscle - because they don't want to carry any extra weight, rowers tend to be very lean.

There is also a lightweight category for men who weigh less than 72.5kg and women who weigh less than 59kg.

These athletes are still pretty tall - men about 1.80m and women 1.70m.

Coxes steer the "eights" boats and often also give their crews instructions and motivation during the race.

They must weigh a minimum of 55kg for men and 50kg for women.

Rowers don't want to carry any more weight than they have to, so coxes generally weigh exactly the minimum.