Boxing Round Timer

Precision timing is the backbone of combat sports conditioning. In disciplines like Boxing and MMA, the physiological adaptation relies entirely on the strict adherence to the work-to-rest ratio, typically represented as t_work : t_rest. A deviation of even a few seconds disrupts the targeted energy system training (Phosphagen vs. Glycolytic).

This tool is engineered with a Drift-Corrected Temporal Engine. Unlike standard JavaScript setInterval loops which suffer from execution delays (event loop blocking), this timer calculates the delta between Date.now() and the expected timestamp on every tick, ensuring ±1ms accuracy over long sessions. It includes specific modes for standard pugilism, mixed martial arts, and high-intensity interval training, utilizing the Web Audio API for latency-free auditory cues.

The core logic utilizes a state machine where the total session duration T is calculated as the summation of preparation, active work intervals, and recovery periods.

To prevent timer drift (Δt), the engine calculates the error on every frame:

Error = (Date.now() - startTime) - expectedTime

If Error > 100ms (e.g., due to background tab throttling), the timer essentially "fast-forwards" the state to match the wall-clock time.