Caffeine delivers true performance gains.
minutes of exercise. This is when caffeine can help significantly decrease
glycogen depletion. Even though caffeine reaches its highest levels in the
blood 45 to 60 minutes after ingestion.
Due to its positive effects on exercise performance, some organizations — such as the NCAA — have even started to ban it in high doses.
One study found that 9.8 mg/lb (4.45 mg/kg, or about 400 mg total) of caffeine increased endurance in athletes.
They were able to cover 1.3–2 miles (2–3.2 km) more than the placebo group.
In a study of cyclists, caffeine was shown to be superior to carbs or water. It increased work load by 7.4%, compared to 5.2% in the carb group.
One study combined caffeine and carbs, which improved performance by 9% compared to water alone, and 4.6% compared to carbs alone.
In a 1,500-meter run, regular coffee drinkers were 4.2 seconds faster than those drinking decaf. Another study found that coffee helped reduce the perception of effort, allowing athletes to work harder.
fat as its primary fuel source. By utilizing fat as fuel, this allows the body to spare glycogen, which is an additional fuel source for the body stored in the muscles and liver. By delaying muscle glycogen depletion, exercise can be prolonged enabling the athlete to go harder, longer, faster and perform more reps before fatigue.