Twenty years ago, Dr Louis Crowe, an Irish Medical Doctor, went for a swim in the cold Irish sea. It was freezing! But on getting out he noticed something about the way he shivered... his teeth chattered in rhythm with his legs shaking.
He began to pay attention. He realized his shivering was synchronized and had a kind of rhythm (with shudders superimposed). There must be a reason why shivering is so specific in its pattern of muscle contractions. Why these muscle contractions are unlike any other.
In that moment, he had an epiphany that would change the course of his life.
Why we shiver the way we do and how this can be mimicked.
Obviously, like everyone else Dr Louis knew we shiver to create heat. When our core body temperature drops and we need to generate heat "without doing anything" we shiver. He reckoned that this must be the optimal way for the body to create heat... or burn calories [a calorie is just an scientific term for a quantity of heat].
So, he began studying shivering, using himself as a guinea pig.... he says those were cold uncomfortable days! He noticed, if he let himself get colder and colder, he'd shiver more intensely but with the same rhythm. His shivering would generally start in his thighs then spread until even his teeth were chattering.... but all in unison in what seemed a magic rate (7-8Hz).
What seemed to happen was that a few muscle fibers would start contracting and then more and more would would contract 'in time'. And this would spread to more and more muscles.
Interestingly if you super-imposed a muscle contraction to stop the shivering.... despite the 'muscle tightening' you seemed to create less heat not more! That the muscle shortening and in particular lengthening was necessary to maximize heat generation. From a physiological perspective this made sense as energy is consumed at the un-linking of fibers... allowing them to slide over each other (lengthening due to the natural recoil of the body).
By mimicking these pulse patterns - like playing music to muscles in the form of electrical pulses, Dr Louis found a way to induce intense shivering without coldness, and in doing so, invented a new form of exercise.
When you shiver you burn just a few times what you burn at rest. While this can keep you from dying from the cold it is not enough to really exercise you hard or make you breathless. The reason for this is that even as your 'whole body' is shivering the contractions are confined to a particular muscle type. By playing with the electrical impulses used to induce the muscle contractions a much greater muscle mass could be recruited. All at this magic rhythm .... maximizing heat generation.
Harnessing your body's biggest muscle group – your legs.
In order to achieve exercise-like effects on the heart, Dr Louis knew he needed to focus on his body’s largest muscle groups – the legs.
By stimulating his legs to rapidly contract and relax, with high intensity, using the special shiver-patterns recruiting deep muscles, Dr Louis was able to achieve real exercise like effects – sweat, perspiration, rapid breathing and an elevated heart-rate. All the things you expect of intense exercise.
Peer Reviewed Science.
Twenty years after his discovery, Dr Louis Crowe has become one of the World's foremost experts in this science of neuro-muscular stimulation. He has completed numerous peer-reviewed studies with leading universities and led innovation teams within medical technology companies. His research has been conducted in associated with leading European Universities and even the European Space Agency.
Through his research, he has proven that from stimulated shivering, applied to legs, via special electrical signals, he could:
- Burn calories rapidly - at levels equivalent to intense exercise
- Increase a person’s heart rate - to levels equivalent to intense exercise
- Enable sustained cardio exercise - once you had trained up with it
- Increase a person’s VO2 Max levels, i.e. boost aerobic fitness
- Deliver the benefits of exercise in a way that is gentle on the joints
All-in-all, it wasn't a bad result from getting way too cold on a morning swim in the wild Atlantic.