The data to include in a workout log as you exercise is the date, your body weight, the name of the exercise, the amount of weight used (if any), the number of sets and the number of repetitions. If you choose to run or do other types of cardio, include the distance, intensity, time and the rest interval between reps in your workout log. A good fitness log makes the information you record easy to use and versatile.
The reason to keep a workout log is to chart your progress and see whether or not your fitness and strength improve over time. If you struggle with certain exercises, it is reflected in your log. As such, review of the data is a fundamental step to grow stronger and more physically capable, lose weight or accomplish any other workout goal.
Today, many fitness apps exist for use on any smartphone or tablet. However, a handwritten notebook is preferable for ease of use, accessibility and flexibility. The best type of notebook to use is a small, durable notebook that survives sweaty and intense workouts both indoors and outdoors and adapts to everything from marathon training to CrossFit training; some fitness log experts prefer a Moleskine notebook.