Training fasted, but still want something in the tank before you start? The options are limited if you're trying to keep your fast intact.
Most pre-workout drinks and gels have calories, which breaks a fast. Black coffee doesn't, and neither does chewing gum, technically, since almost nothing is absorbed as calories — though check the label if strict fasting rules matter to you.
That's the appeal of a caffeine-only gum for fasted training — a fixed 50mg hit without the carbs or sweeteners that come in most pre-workout formulas.
Neuchu is sugar-free with 50mg of natural caffeine per piece. You can find it here.