A vein in my forehead is about to burst. Sweat streams off my nose. I’m on a stationary bike, hooked to cords and monitors, a hamster on a wheel, legs spinning, lungs gasping, heart-rate racing to 168 ...

One of the best measures of running fitness is lactate threshold (LT), which is the running speed or heart rate at which lactate — an intermediate product of aerobic metabolism in the muscles — begins ...

One critical component of customizing fitness and training is having a solid gauge of fitness and its progress over a season and year-to-year. Outside of laboratory-based tests, a standardized field ...