Athlete Series Black cherry with other natural flavors. Gluten free. Certified organic by QAI. +50 mg caffeine (3 Clif Bloks contain 50 mg caffeine). During. Athlete series. As an athlete and Clif Bar’s founder, I’ve enjoyed my share of Clif shot energy gels. But after countless miles of training and racing, l realized it was time to expand the options, which is why we created Clif Bloks Energy Chews. Made from ingredients that deliver quick energy, Clif Bloks come in delicious, bite-size pieces so you can easily customize your sports nutrition. Gary - Founder and Co-owner of Clif Bar & Company. clifbar.com. 1-800-CLIFBAR M-F 8-5 PT clifbar.com.