iPhone Heart Rate Monitors

Learn how to choose and use a heart rate monitor to track HR target zones for training, weight-loss and overall cardiovascular fitness.

Learn how to train using a heart rate monitor, what your HR max is and how to determine it, and how to calculate and use heart rate training zones.

Does a high VO2 max mean you’re in shape? We explain what VO2 max indicates and how to improve your VO2 max score through aerobic exercise. 

Thinking about running a marathon? This article will help you get started with tips on training, hydrating, fueling and more.

Planning to run 26.2 miles in over five hours? Here are some training and racing tips to set you up for a positive marathon experience.

How much do runners, cyclists and other endurance athletes really have to gain from training based on their VO2 Max?