We’ve already talked about how the heart deals with the regulation of blood during exercise, but now it’s time to learn about the lungs.
Where the blood flow around the body increases during exercise, ventilation (breathing in and out) does exactly the same. Because our oxygen demands have increased, delivery of oxygen to the tissues and removal of excess carbon dioxide also needs to increase. This means we need to move more air into and out of the lungs. That is, our breathing rate needs to go up. We also need to deliver more blood to the lungs to pick up oxygen and to deliver carbon dioxide. The cardiac output to the lungs therefore, also increases with exercise.
Under normal resting conditions, we inhale and exhale about half a litre of air with every breath and in total about six litres every minute. In order to fuel increased metabolism with exercise, this respiration rate needs to increase. Again, depending on the intensity of exercise-- low, moderate, or strenuous-- ventilation rate and depth will change several-fold, perhaps up to 30 times, in elite athletes during strenuous exercise. The increased oxygen consumption with exercise is driven by this coordinated increase in cardiovascular, muscular, and respiratory activity. So your heart, muscles and lungs working together to make sure your at your peak during activity. The maximum amount of oxygen that you can use is termed the VO2 max and is a measure of aerobic fitness. VO2 max responds very well to repeated exercise bouts, meaning the more exercise you do, the higher you’ll push your VO2 and thus, the fitter you become!
It’s not just the heart and lungs that are working hard…
What other immediate changes do we see in the body in response to exercise? The brain coordinates and regulates many of the activities related to exercise. But it also responds to exercise, resulting in increased feelings of alertness and focus and, ultimately, fatigue if exercise is prolonged. The release of endorphins, characterised as the runner's high, is well documented. But other hormones and neurotransmitters are also released during and after exercise, including serotonin: that delightful chemical neurotransmitter that’s cited as balancing our moods.
This may contribute to the long-term effects of exercise on brain health. Overall, the responses to exercise are regulated by the nervous system and the hormonal system, both in the short-term and in the long-term.
How your body responds to exercise will differ depending on the type of exercise you’re undertaking. A brisk walk will not be the catalyst to your heart pumping seven times faster than usual, but it will make a difference in the way your lungs, heart and brain work. Activity levels, however slight, will help you to build your VO2 max and get your body healthier and happier!
This blog was written by Anna Clayton: Anna works at Bury Physiotherapy Clinic as a Senior Musculoskeletal Physiotherapist and has recently completed a MSc in Advanced Physiotherapy. She teaches regular Pilates classes including a Pink Pilates; specifically for breast cancer patients. At the clinic she offers patients acupuncture alongside other treatment techniques to help people back to normal day to day activities, sports and hobbies - she is all for functional movement! Anna enjoys keeping fit and active with regular running (the odd half or full marathon), occasional cycling and was a rower and heptathlete in her youth.