NLR: An incipient marker to monitor inflammation, overtraining, and recovery in athletes

Abstract

Neutrophil-to-Lymphocyte ratio (NLR) is a simple parameter used for easy assessment of the inflammatory status of a subject. NLR is calculated by dividing the absolute neutrophil count by the definite lymphocyte count. NLR reflects the balance between the innate and adaptive immune systems. Recently, NLR has been used as an essential biomarker of inflammation, infections, and postoperative complications and has displayed a correlation with the circulating level of C-reactive protein. More recently, NLR is also being used to assess the systemic inflammatory status in athletes. In athletes, altered neutrophil and lymphocyte counts ensued during and after the exercise, resulting in the altered neutrophil-lymphocyte ratio (NLR). Usually, NLR returns to the normal range within 6-9 hours after the cessation of training, but it takes more than 24 hours to reach the basal state if the exercise is prolonged and stressful. Thus, NLR seems to be a good measure of exercise stress and subsequent athlete recovery. Moreover, estimation of NLR requires no exertion from the athletes, and it can be assessed within a minimum time frame and is cost-effective. So, the assessment of NLR is advantageous in monitoring the post-exercise recovery and exercise-induced inflammation in athletes.