Before revision:  The results demonstrate the feasibility of dynamical statistical analysis of RRI's to monitor excercise load in real time with wearable devices and without previous knowledge of external parameters such as the maximum heart rate of the individual.
After revision:  The results demonstrate the feasibility of dynamical statistical analysis of RRI's to monitor cardiovascular exercise conditions in real time with wearable devices and without previous knowledge of external parameters such as the maximum heart rate of the individual.