Maximum aerobic capacity of underground coal miners in India.

Miners fitness test was assessed in terms of determination of maximum aerobic capacity by an indirect method following a standard step test protocol before going down to mine by taking into consideration of heart rates (Telemetric recording) and oxygen consumption of the subjects (Oxylog-II) during exercise at different working rates. Maximal heart rate was derived as 220-age. Coal miners reported a maximum aerobic capacity within a range of 35-38.3 mL/kg/min. It also revealed that oldest miners (50-59 yrs) had a lowest maximal oxygen uptake (34.2 ± 3.38 mL/kg/min) compared to (42.4 ± 2.03 mL/kg/min) compared to (42.4 ± 2.03 mL/kg/min) the youngest group (20-29 yrs). It was found to be negatively correlated with age (r = -0.55 and -0.33 for younger and older groups respectively) and directly associated with the body weight of the subjects (r = 0.57 - 0.68, P ≤ 0.001). Carriers showed maximum cardio respiratory capacity compared to other miners. Indian miners VO(2 max) was found to be lower both compared to their abroad mining counterparts and various other non-mining occupational working groups in India.