Applications of the Running 3-Min All-Out Exercise Test: An Update

Abstract

Abbreviations: 3MT, 3-min all-out exercise test; CS, critical speed; D', curvature constant of the speed-time relationship; t LIM , time-limit for sustaining a given running speed and traveling a given distance IntroductionThe running 3-min all-out exercise test (3MT) estimates the parameters of critical speed (CS) and the curvature constant of the speed-time relationship (D'; pronounced D-prime).1 Critical speed is presumed to represent a mechanical measure of the maximal aerobic steady state, demarcating the heavy and severe exercise domains. 2Exercise in the severe domain relies upon the continual, timedependent depletion of phosphocreatine, 3 the time-dependent rise in blood lactate 4 and evokes a slow component of oxygen uptake that can culminate with attainment of the maximum oxygen uptake at and just prior to the time of exhaustion (t LIM ). 5 The higher the D', the longer distance a person can travel running at speeds exceeding CS before reaching t LIM . By using the parameters of CS and D', the sport scientist can predict the time or speed one can run different distances (note: typically distances spanning 1,000 to 5,000 m). 1The running 3MT has enormous potential for developing racing strategy and is a useful field test for monitoring changes in both endurance and high-intensity exercise capacity.6 Although much is written about the utility of the 3MT to indirectly measure physiological mechanisms governing CS and D', 2 less is known about the utility of 3MT for tactical running situations. The purpose of this review is to provide on update on running 3MT and to discuss developments for the test beyond continuous running events. DiscussionThe running 3MT involves having the subject run at high-intensity speeds sufficient to exhaust all of D' within a 150 sec duration, whereby the speed of the remaining 30 sec will be equivalent to CS. The subject should be directed to build up their speed progressively to avoid a muscular injury (e.g. strained hamstring) and then maintain that speed for as long as they can. The timing of the 3MT can be performed using global positioning sensor (GPS) technology, 1 video recorded times for specified waypoints, 7 or by manually recording split times at specified waypoints.8 The latter two timing methods are conducive for indoor running, whereas outdoor GPS monitoring allows for testing a large number of subjects in a short period of time (i.e., an entire sports team tested in less than 30min).1 The speed of the initial 150sec (S 150s ) is then used to derive D' using: D=(S 150s -CS) 150sec.1 As a concern for pacing exists, we recommend calculating the slope of speed relative to time during last 30 sec of the test ( Figure 1). 9Figure 1 Example shuttle running 3-min all-out exercise test. Take notice of the more apparent acceleration and deceleration curves during the initial test. The slope is reported to confirm a nadir of speed relative to time (note: the closer the value to zero, the better).Individualized distance-time and speed-time curves can be derived using data ...

Optimization of the Critical Speed Concept for Tactical Professionals: A Brief Review

“…Such verifications are certainly suitable for research investigations where CS/CP is a main dependent variable; however, research indicates such steps are not necessary for the field assessment of CS and D ′ and HIIT exercise prescription. For use with tactical professionals, the 3MT can investigate the effects load carriage has on the integrated bioenergetic parameters [ 18 , 25 ] and the utility to prescribe interval training with load carriage [ 19 , 31 ].…”

“…Running performance depends on both CS and D ′ due to the hyperbolic relationship between running speeds, distance, and performance times [ 28 ]. Critical speed has been shown to predict completion times, load carriage performance, and prescribing interval training [ 19 , 29 , 30 , 31 , 32 , 33 ]. More recently, conditioning programs using the CS concept to define high-intensity interval training (HIIT) have emerged with athletic [ 29 , 34 ], non-athletic [ 30 ], and tactical populations [ 19 ].…”