There are many types of exercise to choose from which all have their own benefits. What’s common among all is they require some form of muscular contraction. There are four different types of muscle contraction:
All lifting exercises require Isotonic contractions. This happens when the muscle shortens as it contracts. An example of isotonic contraction can be seen when we flex the bicep muscle. Don’t forget to warm up and strech your body before you start with any exercise.
Stand with one arm straight and the palm of the hand facing up. Roughly measure the length from the start of the biceps muscle to the point where it meets the shoulder. Now curl the hand towards the shoulder, the biceps muscle shortens as it contracts. When you reach the end point take another rough measurement of the biceps again, it will be much shorter.
Another exercise example is the triceps muscle (opposite of biceps). Do the same experiment again, but this time you have to measure the triceps and start at the curled position. The triceps shortens as the arm straightens.
Other examples are:
- lifting objects above the head – front shoulder (anterior deltoid) shortens
- lifting object up from lying position – chest muscle shortens
- lifting body up from squat position – quadriceps muscle shortens as legs extend
- doing a sit up
- throwing a ball
- swinging a bat
In fact, isotonic contractions are the most common, many exercises and activities involve this type of contraction. To learn why muscles shorten during an isotonic contraction click on the next link!