BBC地平線：生物鐘：身體運轉的奧祕

We all have a biological clock ticking away inside us that governs our daily rhythms. This affects our health as much as our diet and whether we exercise. So what can we do to manage this internal clock better? 　　To find out, evolutionary biologist Ella Al-Shamahi locks former commando Aldo Kane in an abandoned nuclear bunker with no way of telling the time - for ten days. Monito...