This week's question

Efficiency involves an input and an output. It‘s about the relationship between the amount of energy coming in – in other words, the food we eat - and the amount of the energy going out – the usual movements and activities of day-to-day life. So, according to this definition, which animal is the most efficient?

a) an ant
b) a whale
c) a human

Listen to the programme to find out the answer. 

Vocabulary

crouched
bent at the knees, closer to the ground and leaning forward slightly

dogleg
having a bent shape, like a dog’s leg; a sharp bend in a road or path 

optimal age
best age; age at which you are most likely to succeed in an activity

drops off
decreases in amount or quality

sweet spot
best possible combination of factors or circumstances 

muscle mass
the amount of muscle in your body, as opposed to fat or bone