Final answer:
You're likely experiencing sensations due to muscle fatigue, lactic acid buildup, and response from somatosensory receptors due to physical exertion. This occurs as the body uses energy and tries to protect muscles from overexertion and injury.
Step-by-step explanation:
During physical exertion, the sensation you're experiencing, which is similar to pins and needles but more subdued, could likely be due to a combination of factors such as muscle fatigue, lactic acid buildup, and nervous system responses. When engaging in intense physical activity, our body utilizes lactic acid fermentation to generate ATP. However, a byproduct of this process is lactic acid, which can accumulate in the muscles, potentially leading to that burning sensation. Additionally, muscle fatigue can result from prolonged or intense exercise when a muscle can no longer contract effectively due to depletion of ATP or disruptions to ionic balances affecting muscle contraction.
Another contributing factor can be the stimulation of somatosensory receptors within the muscles and joints. Muscle spindles and Golgi tendon organs act as stretch receptors and can respond to changes in muscle tension and length. When overexertion occurs, these receptors might contribute to the sensations you're feeling as they try to prevent over-stretching or over-contraction to protect the muscles from damage.
It is crucial to listen to your body and allow for adequate recovery time when experiencing such sensations to prevent injury and promote the repair and strengthening of muscle tissues.