How do various factors affect muscle fatigue?
Introduction:
In this experiment muscles will be tested with weight, to see if weight is truly a factor in muscle fatigue. Muscle fatigue is the muscle’s ability to contract exert its normal strength due to physical stress upon it. The structure of a muscle include a thin layer called epimysium which surrounds the entire muscle, deeper to the epimysium is the perimysium. This layer contains fascicles which are bundles of muscle cells. In between the muscle cells are endomysium which is just connective tissue. The muscle cell (fiber) can be broken down even futher. Deeper to the muscle fiber is the sarcplasm which is cytoplasm in the muscle cells, this cytoplasm contains myofibrils which are just bundles of filaments. Now, myofibrils shorten, tis makes muscles contract and allows for movement. Some functions of musces in our bodies include motion, maintenance of posture, and heat production. Macromolecules that aid muscle contraction are the proteins myosin (thick filaments) and actin (thin filaments), the way that this is done is that they overlap each other and during contraction which makes the muscle “shorten”.
Hypothesis:
As more weight added to the load that a muscle is lifting, the muscle will go through muscle fatigue faster.
Prediction:
If a person lifts two loads, one light in mass and another that is greater in mass, then the person’s muscles will fatigue faster when lifting the load with the greater mass.
Materials:
* Stopwatch * Two Books
Procedure:
1. Have Person 1 hold a book in their dominant hand as they are standing. 2. Now, Person 1 will now elevate the arm that they have the book in laterally (as if doing jumping jacks without the jumping), and they will bring it back down once their arm has leveled with their shoulder. 3. Person 1 will continue this exercise until they can no longer lift the book. (don’t forget to record how long they last with a stopwatch).