Start of the women's 400 m freestyle at the 2008 European Championships. Image: Miho.

Some very exciting medals are going to be won in swimming today, including the women's 200m butterfly and the men's 100m freestyle. But we're unlikely to see the rush of record-breaking performances we saw in Beijing in 2008 — that's because in 2008 many swimmers benefited from controversial high performance swimsuits, which have now been banned. But how did these suits improve performance? Find out in By the skin of their suits.

Staying on the aquatic theme, the male divers are also competing for medals today and they'll need a good sense of balance to stay on those springboards. Our sister site Maths and sport: Countdown to the Games has a nice activity on balance and the mathematical concept behind it: inertia. It's aimed at higher GCSE and A level students.