Can caffeine really help you lose body fat? Yes! The way it works is that it increases your heart rate, where you are in the aerobic zone to burn fat without moving much. An example of a fast heart rate and low body fat can be embodied by slim people or HardGainers (a person who has difficulty gaining weight either through diet or exercise) and measuring their pulse. You will find that their resting heart rate is around 90 beats per minute (bpm) and when they walk for a few minutes their heart rate can jump to 120 bpm. HardGainer’s can burn fat quickly; while other people like me need to jog to reach 120 bpm.
Now I’m not saying slim people have it easy or having a high pulse all the time is good. It is unhealthy to have your heart work hard all the time. Stress can also increase your bpm but I would not recommend stressing yourself to lose weight because stress causes sleep reduction, appetite increase, and makes it difficult to gain muscle.
For people who need to lose weight AND who exercise, caffeine can help in a few ways: 1) Caffeine speeds up metabolism. 2) It breaks down fat about 30% more efficiently if consumed prior to exercise. 3) It keeps your blood sugar levels elevated, so you don’t feel as hungry (paraphrased from About.com – Stress Management article).
Keep in mind the side-effects of caffeine. Caffeine changes the following chemical levels in your body: Hormones, Adenosine, Adrenaline, Cortisol, and Dopamine. These can cause issues from reduced sleep, increase in stress, to even heart disease and diabetes.
If you decide to try caffeine to help you burn some stubborn fat quickly, take caffeine pills before you do cardio. But DO NOT use caffeine for weight training because you will not get sufficient rest between your sets. If you are sensitive to caffeine, take it before 2 pm (caffeine stays in your body for approximately 8 hours). Finally, always use in moderation. Taking anything in excess is never good.
Note: Caffeine has a risk of physical dependence, so please check with your doctor before starting a caffeine regimen.