Muscle cells produce lactic acid during anaerobic fermentation. A buildup of lactic acid cause your muscles to feel tired.
Muscles will form lactic acid through anaerobic glycolysis to produce ATP in the absence of oxygen. This process allows for continued energy production when oxygen levels are limited, but can lead to muscle fatigue and soreness due to the buildup of lactic acid.
A muscle is either contracting (doing work) or relaxing (not under tension). Some muscles do not ever completely relax under normal conditions.
Relax. Muscles can only work by contracting (tensing). When an opposite force is desired, an opposite muscle contracts.
Kegels
Muscles relaxing and contracting.
By contracting muscles in their body.
Muscles relaxing and contracting.
the coulor
When your quadriceps bulge out, these muscles are likely contracting. Contraction of the quadriceps muscles results in a bulging appearance due to increased tension and activation of the muscle fibers.
The answer is "True"
Diaphragm and intercostals
The extensor back muscles help to keep the spine upright and stable by contracting to extend the spine and maintain proper posture. They provide support and strength to the spine, helping to prevent slouching and maintain a healthy alignment.