Short-term effects of anaerobic lactic exercise on knee proprioception of track and field athletes

BACKGROUND: Proprioception is affected during sports events, thus jeopardizing performance and even the well-being of athletes. To effectively control the injury risk and performance, sport professionals should find out how long the proprioceptive damage lasts.

OBJECTIVE: To analyze acute effects of an anaerobic lactic exercise on the knee joint position sense of athletes and the duration of these effects until twenty-four hours later.

METHODS: Fifteen athletes performed two training sessions one week apart: Warm-up: 30-minute warm-up; and Lactic Exercise: 30-minute warm-up and an anaerobic lactic exercise session. All athletes carried out a joint position sense test of knee, as well as a blood lactate and heart rate analysis before(Pre), just after (Post $_{0Min}$ ), thirty minutes after (Post $_{30Min}$ ) and 24 hours (Post $_{24H}$ ) after each training session.

RESULTS: Absolute angular error in knee positioning increased just after Lactic Exercise with statistically higher values than after Warm-up Exercise(p=0.001) and gradually decreased toward 24 hours later. Relative angular error in knee positioning decreased statistically significant 24 hours after Lactic Exercise (p=0.021).

CONCLUSION: Anaerobic lactic exercise immediately depletes the accuracy of knee joint position sense, although it is recovered 30 minutes later. After 24 hours, knee joint position sense is better than baseline.