Measuring muscle force

The force of a muscle is measured in newtons (N). Some muscles can pull much harder than others.

• A force meter measures force in newtons. You pull on some kinds, and push or squeeze others. Use all your strength, then read the scale.
• Bigger muscles usually give bigger forces. The thick muscles in your thigh pull harder than the small muscles that move a finger.
• Training can make a muscle bigger and stronger. A tired muscle gives less force.
• Repeat each measurement. Take three readings and work out the mean.