Extremes

We only get one body, and that one is pretty fragile. It doesn't stop some people from pushing it, though

Fire hose: but could it also be a bungee rope?

Bungee jump or suicide leap?

Could Bruce Willis have saved the world with a singlet and a hosepipe - or would he just have created a nasty way to Die Hard?

Breathing lessons

Jonathan explains to Kate why breathing underwater gets trickier the deeper you go in the beneath the waves video extra.

Taking a chance

Kris Akabusi investigates the need for speed and asks why some people are attracted to the allure of danger.

A contestant in The World's Strongest Man

Charge yourself up

Faster, faster! Kris Akabusi gets his heart pumping as he finds out the secrets to physical power.

On the spot

Footballers can be made famous by a memorable goal. Yet what lies behind those perfect penalties?

Sperm

Mike and Zeron find out how to keep their sperm in tip-top shape, make plaster casts of their testicles and take part in the world's first on-screen sperm race in able-bodied semen.

G-force

Mike and Zeron compete for the chance to ride in an F-16 fighter plane in 'Fit to Fly'.

Sleep

Mike Leahy battles to stay awake for over 60 hours to determine the effects of extreme deprivation on the body in 'Up All Night'.

Fear

Mike climbs a crane to combat his fear of heights, and Zeron sleeps with Boa Constrictors to overcome his extreme snake phobia. Confronting fear is the name of the game in scaredy rats.