The physiological responses to a USRPT (Ultra-Short, Race-Pace Training) set was measured in a recent study (Williamson, et al., 2020). Fourteen university swimmers performed 20 x 25 meter swims on a 35 second send-off interval. Heart rate and blood lactate values are shown in the graph below. The authors cautioned about the “acute physiological responses,” but acknowledged that “the specificity of USRPT in terms of technique, psychology and conditioning performed at race-relevant velocities would be desirable approaching competition.”
