Degree of strength, energy, or difficulty; as related to a workout: the class level.
The strength or loudness of a particular sound, measured in decibels.
The strength of e.g. pain.
A state of increased force, muscle vigor, or energy.
Action potential firing that encodes the strength of a stimulus.
The condition of extreme effort or the characteristic of being profound; it can be communicated through the measure of heart rate, the intake of oxygen, or the concentration of lactate in the blood.