Carey and Bonnie decided they wanted to run in the Boston Marathon. Carey traine
ID: 89822 • Letter: C
Question
Carey and Bonnie decided they wanted to run in the Boston Marathon. Carey trained for months for the event. Bonnie was a regular short distance runner and figured she didn't need any special training for a marathon. On the big day, Carey paced herself and proudly finished the marathon. In the crowd she had lost contact with Bonnie, who was nowhere to be found. Bonnie never made it to the finish line. Half way through her muscles began to ache, her breathing became hard and her heart was racing. She tried to run through the pain but eventually she felt like a brick wall came crumbling down on her. She fell to the ground and couldn't get up. Using your knowledge of muscle physiology, what do you think happened to Bonnie? What effect will rest and hydration have on her muscles?
Explanation / Answer
If the body has to perform exercise for a particular duration, it needs energy. The energy is given to the system in the form of adenosine tri phosphate or ATP. ATP is stored in the skeletal muscle which is directly used by them for the purpose of contraction. The limited stores of ATP in the body are generally sufficient for 2 seconds of sprinting and it has to be resynthesized from other sources through various pathways.
The duration and intensity of the event determines the energy system needed for providing energy. The energy systems in the body are of three types such as immediate, short-term and long-term system.
The immediate system is run by the intramuscular ATP and phosphocreatine. The short-term system is run by anaerobic glycolysis or lactate system which is fueled by glucose, glycogen and glycerol backbone of triglycerides. The long-term system is run by aerobic glycolysis, oxidative phosphorylation of the macronutrients like lipids, proteins and carbohydrates.
Each of these energy systems are used to generate ATP sufficiently and avoid fall in the intramuscular concentration of ATP.
Here in the question, Carey has muscles that are tuned up to long-term energy system and due to supply of oxygen to the system, Carey could manage to finish the marathon. Bonnie has the experience of running short distances and she does not have the habit of supplying oxygen to the body metabolism while running (proper breathing). So, the short term energy system functions for her and gradually the formation of lactate will lead to muscle fatigue. Hence, Bonnie could not continue the marathon further.