Field-dependent relaxation profiles are most often collected with field-cycling (FC) relaxometers. FC relaxometry can allows for the measurement of nuclear relaxation rates from fields as low as 0.01 MHz proton Larmor frequency (B0  200 µT), up to tens or hundreds of MHz, i.e. over 3-4 orders of magnitude. No spectral resolution is however possible due to the relatively poor field homogeneity, so that only the collective relaxation of all nuclei of a given isotope in the sample can be measured. 1 H relaxometry measurements on water solutions of biomolecules are thus typically dominated by the relaxation rates of bulk water protons, so that the relaxation profiles can report only the relaxation rates of these protons. Therefore, information on the dynamic processes occurring in the system can be retrieved by modelling the effect that the different time-dependent interactions between water molecules and biomolecules have on water proton relaxation and its field-dependence.