Incidence of Non-Response and Individual Patterns of Response Following Sprint Interval Training

The current study sought to explore the incidence of non-responders for maximal or submaximal performance following a variety of sprint interval training (SIT) protocols. Data from 63 young adults from 5 previously published studies were utilized in the current analysis. Non-responders were identified using 2 times the typical error (TE) of measurement for VO2peak (2 x TE = 1.74 mL/kg/min), lactate threshold (2 x TE = 15.7 W), or 500 kcal time to completion (TTC; 2 x TE = 306 secs) trial. TE was determined on separate groups of participants by calculating the test re-test variance for each outcome. The overall rate of non-responders for VO2peak across all participants studied was 22% (14/63) with 4 adverse responders observed. No non-responders for VO2peak were observed in studies where participants trained 4 times per week (n=18), while higher rates were observed in most studies requiring training 3 times per week (30-50%; n=45). A non-response rate of 44% (8/18) and 50% (11/22) was observed for the TTC test and lactate threshold, respectively. No significant correlations were observed between the changes in VO2peak and TTC (r = 0.014; p = 0.96) or lactate threshold (r = 0.17; p = 0.44). The current analysis demonstrates a significant incidence of non-responders for VO2peak and heterogeneity in the individual patterns of response following SIT. Additionally, these data support the importance of training dose and suggest that the incidence of non-response may mitigated by utilizing the optimal dose of SIT.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author