Tracking heart rate and calories burned during my tennis matches has always been difficult because of the limited range of Bluetooth technology. The TICKR X’s memory feature has finally solved this problem. Before each match, I put on the X, and leave my phone in the tennis bag. The X records and stores my heart rate and calories burned during the entire match. At the end of each set, I use the double tap feature on the X to create a marker to designate set breaks. After the workout, the Wahoo app provides a simple, straightforward analysis of how my body performed while on the court. Heart rate data is graphed over time, and I can see exactly when my body was pushed to the limits. I’ve noticed my heart rate slowly rises throughout the duration of the match, and is particularly taxed in the last set. In response, I’ve worked to improve my conditioning off the court with longer runs to build up my cardio endurance.