What are the most effective methods for integrating a hydration monitor or smart water bottle into a cycling setup to accurately track fluid intake during a ride, and how do these systems account for factors such as temperature, humidity, and individual rider variability in fluid loss rates? Specifically, how do hydration monitors and smart water bottles utilize data from accelerometers, GPS, and other sensors to provide actionable insights into a riders hydration status, and what are the key considerations for choosing a system that meets the unique demands of cycling?