The use of radical-based chemistry allows for amazing transformations in living organisms. To carry out their functions, radical enzymes often need to be flexible and assume different conformational states. In this talk, the conformational gymnastics involved in ribonucleotide reduction are considered. Ribonucleotide reductases (RNRs) are radical enzymes that convert ribonucleotides (the building blocks of RNA) to deoxyribonucleotides (the building blocks of DNA). RNRs are targets for cancer chemotherapies and have been proposed to be candidates for antimicrobial therapies. Here, I will describe how my lab has employed biophysical methods to interrogate how RNRs shake, rattle, and roll to accomplish their critical cellular function.