nextpb.vip hosts the Race HR Pacing Calculator — a free tool designed to give you an ideal, realistic pacing plan for running your fastest race. It adapts to the shape you're in and the circumstances of the day — heat, wind, course profile — by focusing on heart‑rate as a proxy for internal effort.
The calculator combines GPS for ground‑truth pace, optional Bluetooth® HR monitor data, and an adjustable target curve. Start controlled, stay smooth through the middle, and close fast — without blowing up.
Use the guides in the Blog to calibrate zones, handle heat/humidity, and build negative‑split plans that fit your fitness.