To test our approach experimentally, we acquired 1 H, N SOFAST-HMQC spectra of ubiquitin (277 K, 600 MHz), using uniform sampling, or applying 40 s -1 resolution enhancement with both optimal sensitivity (α = 1) and constant noise (α = 2) NUWS schemes (Fig. ). We note that in contrast to hard pulse HMQC experiments, the use of amide-selective pulses in the SOFAST-HMQC means that scalar couplings to Hα atoms are refocussed in the indirect dimension. These experiments are therefore an attractive target for further resolution enhancement.