Peak Detection on ECG signal I've been working on a ECG signal collected during exercise through my chest mount heart rate monitor. My goal is to accurately detect the location of the R-wave; R-wave is the narrow peak similar to the ones I circled in red.

Can you suggest any method for preprocessing the data so that it will be easier to extract the signal?

I have tried wavelet transform but I am not getting any luck. 



You can download the data here. Sampling frequency is 150 Hz.
A typical approach would be the Pan-tompkins algorithm. You can also apply a first order low pass filter or a mean filter to improve results.