The Science of Running: Intro

You pad along the trail, kicking up dust behind you on your weekly long run. As you flow softly forward, each foot takes its turn on the ground, accompanied by a moment of sheer weightlessness as both feet are airborne. Your central torso is held stable by your core, and your large gluteus maximus muscles help hold your form. Your centre of gravity vaults from leg to leg. You feel your leading foot strike the ground, forcing shockwaves up through the lower leg. This leg swings under your pelvis, and prepares to propel you forward as the hips and knee joints extend below you. These paired joints flex and extend until your leg is up behind you, graceful as a ballet dancer. At the exact same time, the other leg and foot are already up and out in front of you, preparing to take you on your next step. 

All the while, complex groups of muscles coax your joints into these flexions and extensions, they stretch and contract. Your heart pumps blood around the body to your muscles and to your brain, pumping quicker and quicker. Your muscles are consuming adenosine triphoshate- an energy molecule that it has created from food- converting it into adenosine diphoshate and also constantly breaking down glycogen and stealing glucose from your bloodstream to make more. Cortisol from your adrenal glands helps this transfer.  Even though you're using fuel, your digestive system shuts down because it isn't necessary in the moment, which is why eating on the run can cause you drama. The oxygen being provided by your strong heartbeat and heaving lungs, which are trying to recruit up to 15 times the oxygen they usually do,  is helping you fuel your movements, because its needed to create more adenosine triphoshate. Your heartbeat is also being raised by the adrenaline rush from adrenal glands. 

Your lungs will keep trying harder and harder, until the lung muscles themselves cannot sustain contraction speed.Their maximum working speed is your VO2 Max.Your heart is working hard, but the more practice both these organs get, the better they will get. This is why your VO2 max and resting heart rate will change with fitness. Your muscles also start releasing lactic acid, a response to being under duress when not enough oxygen is available. Your muscles develop micro tears, allowing them to develop and enlargen when healing, as long as they are well fueled.  Your pituitary gland in your brain releases growth hormones which make you move, but also serve to protect your body from choosing to burn muscle instead of fat after glycogen. 

You're burning calories the entire time, and this consumption of glycogen and oxygen raises your internal temperature. To avoid any danger, your hypothalamus directs the sweat glands open, the eccrine glands create sweat, and your blood flushes to the surface capillaries of your skin to cool, sending a flush through your face. Your brain has released a neurotransmitter cocktail including dopamine, glutamate, serotonin, GABA and endorphines, the famous 'runners high'. Some of these neurotransmitters help control your movements, some emerge as a result of glycogen depletion and serve as a pain mask. Your brain also got a boost from the blood flow, and now has better cell function. Regular exercise will actually effect gene activity, boosting cell function and protecting you from both typical age decline and atypical neuropathological decline. During this function boost, your brain also creates new cells. A lot of the other changes will reverse when you stop exercising, but these cells will stay. After you stop running, your kidneys dump protein into your urine, and absorb more water than before to rehydrate you.

There is so much SCIENCE going on in your body as you run. So many possible combinations of propulsion force and fuel and neurotransmitters and muscle use. Since my background is in science, I thought it might be nice to start a feature looking at the science of running, communicating scientific papers in an understandable way. I'm not a physio, or an expert in biomechanics or gastroentorology or cardiovascular science. I can however speak science, mostly, so I'm going to give it a try. I'll choose a paper each time, on different topics in the science of running, and try to make it understandable. 


If I write these, would you read them?

Please note if anything in the above is incorrect, I'd love to hear about it, I'm keen to learn :-)


  1. Yep! I would! Sounds interesting!

    1. Thanks for your comment :) There was some twitter enthusiasm too, so I likely will!



Blog Archive