Running

Guide breathing online with adjustable inhale, hold, and exhale timing, live pacing cues, and local exports for steadier daily breathwork practice.

Plan endurance fueling online with carb, fluid, and sodium targets for rides and runs so you can turn race nutrition goals into timed intake windows.

Calculate Friel heart rate zones online from threshold heart rate or test averages to pace runs, rides, and structured time-in-zone workouts.

Lookup online good VO2 max ranges by adult age and reference sex, classify an optional measured value, and compare cohort thresholds for training decisions.

Calculate heart rate zones online with age, max HR, or reserve methods, compare formulas, and plan time in zone for clearer workout pacing.

Predict marathon pace online from weekly distance, training speed, and run frequency, then review splits and pacing charts before race day.

Estimate VO2 max online from heart-rate, Cooper, 1.5-mile, or Rockport inputs, compare benchmark ladders, and export results for training review.

Convert running pace and speed online, add distance for finish times, course markers, and split ladders, and compare race projections for pacing plans.

Calculate race finish times online from pace or speed, model pacing profiles, planned stops, and cutoffs, and export split plans for race-day pacing.

Predict race finish time online from a prior result, adjust conditions and Riegel exponent, and compare splits and scenarios for pacing decisions.

Draft race timer suite that consolidates general and athletics race timing into one disabled split-tracking workflow.

Calculate target heart rate online from age or known max HR, compare zone models and hold ranges, and check whether current effort fits your workout plan.