Energy Source 4:1 is the Worlds leading all-in-one training & recovery drink. It contains 4 parts carbohydrate to 1 part whey protein isolate combined with all key electrolytes. With a light refreshing taste. Its easy on the stomach & lactose free. Research shows that a carbohydrate / protein combination can reduce muscle damage during exercise & increase post exercise muscle synthesis when compared to a carbohydrate only drink. Less muscle damage during exercise & more rapid recovery afterwards leads to stronger more resilient muscle, lower risk of injury & more rapid fitness gains. The whey protein isolate used in 4:1 is high in Leucine, an amino acid which triggers protein synthesis. It has an exceptionally high PDCAAS score of 1.14, which is a measure of protein quality. The carbohydrate in Energy Source 4:1 is 2:1 fructose*, which offers many advantages in its own right. For more information see our Energy Source 2:1 fructose page. Energy Source 4:1 contains all key electrolytes & provides exceptional fluid replacement, so its suitable for training & racing in the heat if required.