Fig. 1
From: The pulmonary and autonomic effects of high-intensity and low-intensity exercise in diesel exhaust
Heart rate variability (HRV)Â in 15 males prior to and following rest, low-intensity, or high-intensity cycling: (a) SDNN: Standard deviation of NN intervals, (b) RMSSD: root mean square of successive intervals, (c) HRV triangular index, (d) Low frequency (LF) power, (e) High frequency (HF) power, (f) Total power, (g) LF/HF, (h) LF power normalized units (nu), (i) HF power nu. A summary of significant differences can be found in Additional files 1 and 2