Enzymes are extraordinary biocatalysts that accelerate chemical reactions by performing several complex tasks simultaneously including; (1) binding of substrates weakly enough to avoid thermodynamic pits; (2) extremely tight binding to the transition state compound; (3) activation of functional groups on the substrate(s) and (4) dehydration of active sites. These tasks are often associated with conformational changes and therefore conformational dynamics is by definition crucial for enzymatic function. An emerging paradigm in enzymology is that dynamically accessed transient high-energy structural states are fundamental entities for enzymatic reaction cycles. These high-energy or “invisible” states are not possible to study directly at atomic resolution with existing spectroscopic techniques because their low relative populations and residence times. Here, we have been able to cool down the rate of conformational dynamics of an adenylate kinase (AK) variant to the extent that a high energy ligand-bound state becomes directly observable with solution state NMR spectroscopy. It was found that the catalytic activity of the enzyme is restricted by the dynamic interconversion between the high energy state and a low energy ground state. In complete agreement with the presented catalytic model is was found that the energetic barrier for the catalytic function, as probed with a functional assay, is of the same magnitude as the barrier for conformational dynamics. Our work shows that it is possible to tune the rate constants of conformational dynamics resulting in a predictable perturbation of the enzymatic activity.