Caffeine: a familiar stimulant that needs a clear total amount

This category is for people who want a small boost in alertness before exercise.

Caffeine is one of the easiest ingredients to overestimate because it appears in several places during the day. The useful comparison is the total amount, the time of day, and whether the routine still leaves room for sleep.

Useful comparisons are the amount of caffeine per serving, the format, and how easy it is to keep the total from coffee, tea, cola, and energy drinks in view. Capsules and plain tablets are often easier to count than large flavoured scoops.

Caffeine products should fit the time of day as well as the training session. If late workouts already affect sleep, or if you notice palpitations, restlessness, or stomach discomfort easily, a lower-caffeine routine is usually the safer fit.