A cramp is a sudden, involuntary muscle contraction that doesn’t relax right away. It occurs when the normal balance between muscle activation and relaxation is disrupted. Common contributing factors include: • Neuromuscular fatigue – overuse alters motor neuron firing • Electrolyte imbalance – changes in sodium, potassium, calcium, or magnesium affect muscle excitability • Dehydration – reduces blood flow and alters nerve signaling • Altered biomechanics – muscle shortening, joint positioning,

Cramp or no cramp, that is the question. Alexander Zverev was asked about his thoughts on Carlos Alcaraz receiving treatment for what he believed to be a cramp midway through his marathon match against the world number one. It is against the rules to receive treatment for cramping. Catch all the action from the Australian Open this summer, live and ad-free. Just look for the tennis button on the ABC listen app: https://www.abc.net.au/listen/live/sport Follow our live blog: https://ab.co/4a2UJR9