en فيزيولوژی ورزشی و شاخه‌های وابسته بدان Sport Physiology and its related branches مقاله اصیل Original Article <div style="text-align: justify;"><strong>Background:</strong> Although maximal sprint speed (MSS) and the anaerobic speed reserve (ASR) provides valuable information about the speed profile of athletes, these parameters fall short of providing important information about sub-maximal metabolic thresholds. The only field test that can offer an estimate of a sub-maximal metabolic threshold is the 3-minute all-out test for running (3MT) which delivers three parameters of interest: the critical speed (CS), fatiguability constant (D&rsquo;), and 3MT-specific maximal running speed (MS_3MT).<br> <strong>Objectives:</strong> We offer an alternative to the ASR, termed the &lsquo;functional&rsquo; speed reserve (FSR), and therefore the purpose of this study was two-fold: firstly to compare MSS to MS_3MT and FSR to ASR, and secondly, to determine the correlations between ASR, FSR, and D&rsquo;.<br> <strong>Methods:</strong> Thirty-two participants volunteered for the study (age: 22.50 <em>&plusmn;</em> 4.32 years; height: 1.67 <em>&plusmn;</em> 0.78 m; body mass: 66.58 <em>&plusmn;</em> 11.30 kg) and completed a graded exercise test (GXT), 3MT, and 40-m sprint test following familiarisation bouts for each test.<br> <strong>Results:</strong> MSS and MS_3MT were strongly correlated (r=0.93, p<0.001). The ASR and FSR were also strongly correlated (r=0.77, p<0.05), with the FSR also showing a strong correlation with D&rsquo; (r=0.77, p<0.05).<br> <strong>Conclusion:</strong> The 3MT provides a viable, arguably more ecological alternative to the ASR (i.e. FSR), and provides additional parameters such as CS, D&rsquo;, and MS_3MT. Field testing based on the 3MT can offer coaches and athletes unique performance insights and tools to effectively program and prescribe training interventions.</div> Critical Speed, Maximal Speed, Speed Reserve, Thresholds 0 0 http://aassjournal.com/browse.php?a_code=A-11-1431-2&slc_lang=en&sid=1 Mark Kramer mark.kramer@nwu.ac.za 100319475328460010208 100319475328460010208 Yes Physical Activity, Sport, and Recreation (PhASRec) Unit, North West University, Potchefstroom, South Africa Emma Jayne Thomas emmathomasbio@gmail.com 100319475328460010209 100319475328460010209 No Human Movement Science Department, Nelson Mandela University, Port Elizabeth, South Africa Mariaan Van Aswegen 20383800@nwu.ac.za 100319475328460010210 100319475328460010210 No Physical Activity, Sport, and Recreation (PhASRec) Unit, North West University, Potchefstroom, South Africa