Three thugs pushed a 53-year-old man from his bike, punched him and stole it before running off.

But the crime was witnessed by a passing cyclist who pedalled after them – and captured the entire moment on his helmet-mounted camera that was connected to his heart monitor.

The dramatic chase shows the unnamed hero accelerating to 21mph, while his heart rate soared to double the average resting rate.

The victim can be heard shouting that he had been mugged while travelling along the dark, isolated road in Leyton, East London.