Final answer:
The untrue statement is that one should never increase frequency, intensity, or time while stretching. It is important to progress stretching routines safely and warm-up properly to prevent injuries.
Step-by-step explanation:
The statement that is not true is: You should start stretching at a slow, safe level, but never increase your frequency, intensity, or time. It is important to progress in your stretching routine as your flexibility improves. However, safety should always be a priority. Performing a proper warm-up is crucial before stretching to increase blood flow and decrease the risk of injury. It is true that partner-assisted stretching can result in injury if not done correctly. Stretching muscles when you feel the need is beneficial, but you should be mindful of your body's condition and any potential discomfort or pain. Proper rest and recovery are essential to prevent overuse injuries.