Back from the brink – Fight, flight, and fright (2007)

Hugh Montgomery

 In his fourth lecture,  Hugh Montgomery explains how our bodies deliver all of our energy, all of a sudden.

Watch time: 35:26
A child lifting a yellow arm weight in the Ri theatre
Image credit: Royal Institution

Lecture 4 – Fight, flight, and fright

When confronted by a shark, you must swim for your life, but when a soldier comes face to face with his enemy, he can choose to stand and fight. Both situations demand a huge amount of physical work. In his fourth lecture, Dr Hugh Montgomery explains how our bodies deliver all of that energy, all of a sudden.

In an exploration of the incredible capabilities of the human body, discover what happens to our heart, lungs and blood vessels when our adrenaline levels begin to rise. How is the energy expelled and where does it go?

Our muscles are capable of extraordinary feats of power, too. With the help of a human filament machine, Hugh reveals how the fibres in our skeletal muscles allow them to contract before making two unlucky athletes exercise to exhaustion to demonstrate how speed and stamina are critical when it comes to endurance.

We learn how our brain responds to danger and how the speed of our reactions can be a matter of life or death. Plus, Hugh speaks to Royal Marines Commando Major Phil Ashby, who fought starvation, dehydration and a machete-armed mob in his escape from a warring Sierra Leone. 


When a huge meteorite hit the Earth 65 million years ago, it wiped out the dinosaurs whilst our ancestors survived. Since then our planet has experienced several similar episodes of mass extinction and each time, our ancestors have lived on. We have evolved to withstand the most extreme environments, but what determines our survival?

The science of survival

In his series of five lectures from 2007, geneticist Hugh Montgomery leads an exploration of human endurance and the very thin line between life and death.

Hugh reveals how the body is equipped to perform exercise, adjust to high altitudes, and endure hot and cold climes. Discover how the human body responds when faced with peril, and why some people take flight, whilst others stay and fight. Plus, find out how our bodies deliver the energy we need to react, and what happens to our vital organs when the adrenaline kicks in.

A question of fate?

Along the way, Hugh speaks to real-life survivors who have fought some of the world’s most extreme conditions. From starvation to dehydration, and severe cold to blazing heat, their extraordinary tales remind us of the fragility of human life and the astonishing endurance of the human body.

Why do some people live and some people die in perilous situations? Does our fate boil down to good old-fashioned luck, or does it lie deeper in our genes? And just how much influence does our environment have over our chances for survival?

NB: We do not currently have a version of Lecture 1 available due to technical issues.