Researchers have discovered that eating a bowl of spinach a day makes your muscles "profoundly" more efficient.
They found that eating 300g of the vegetable reduced the amount of oxygen needed to power muscles by as much as five per cent when exercising.
The effect is so powerful it works after just three days.
The secret is not iron but nitrates which are abundant in the vegetable.
These chemicals make the mitochondria – the "engine rooms" of every cell – more efficient, they found. Read more
Popeye's claim that, "I am strong to the finish because I eat all my spinach," is scientifically correct, a study has found.
