Movement detection from Arduino Nano 33 BLE sense

I am looking for someone to help me with a project that involves movement detection from an Arduino Nano 33 BLE sense rev2. The data collected will be used for fitness tracking purposes. Specifically, I am interested in detecting the movement of a runner after the START of a race. The START of the race is done by a button. If runner starts before 100ms, it's a FALSE START. We need to hear a double beep through a basic speaker. If the runner starts after the 100ms, it means the start is correct. On both case, it's interesting to know and display the reaction time between the button start and the start of the runner.

Ideal skills and experience for this project include:
- Experience working with Arduino Nano 33 BLE sense
- Proficiency in programming languages such as C++ and Python
- Familiarity with fitness tracking and/or motion detection technologies
- Ability to provide clear and concise documentation of code and project progress.