http://www.ck12.org Chapter 1. Human Biology
Anaerobic Exercise and Muscular Strength
Anaerobic exercises cause muscles to get bigger and stronger. Anaerobic exercises use a resistance against which
the muscle has to work to lift or push away. The resistance can be a weight or a person’s own body weight (Figure
1.20).
FIGURE 1.20
Anaerobic exercises involve the muscles
working against resistance. In this case
the resistance is the weight of a barbell.Aerobic Exercise and Muscular Endurance
Aerobic exercises are exercises that cause your heart to beat faster and allow your muscles to use oxygen to contract.
If you exercise aerobically, overtime, your muscles will not get easily tired, and you will use oxygen more efficiently.
Aerobic exercise (Figure1.21) also helps improve cardiac muscle.
Muscle Injuries
Sometimes muscles and tendons get injured when a person starts doing an activity before they have warmed up
properly. A warm up is a slow increase in the intensity of a physical activity that prepares muscles for an activity.
Warming up increases the blood flow to the muscles and increases the heart rate. Warmed-up muscles and tendons
are less likely to get injured. For example, before running or playing soccer, a person might jog slowly to warm
muscles and increase their heart rate. Even elite athletes need to warm up (Figure1.22).
When you don’t do a proper warm-up, several types of injuries can occur. Astrainhappens when muscle or tendons
tear. Strains are also known as "pulled muscles." Another common injury istendinitis, the irritation of the tendons.
Strains and tendinitis are usually treated with rest, cold compresses, and stretching exercises that a physical therapist
designs for each patient.
Injuries can also be prevented by proper rest and recovery. If you do not get enough rest, your body will become
injured and will not react well to exercise, or improve. You can also rest by doing a different activity. For example,
if you run, you can rest your running muscles and joints by swimming.
Vocabulary
- aerobic exercise: Activity that increases muscular endurance and cardiovascular health.