High-Intensity Interval Training Prescribed Within the Secondary Severe-Intensity Domain Improves Critical Speed But Not Finite Distance Capacity

Abstract

Purpose Improvements in D′ (the fatigability constant for running) subsequent to training interventions remain elusive. High-intensity interval training (HIIT) within the severe intensity domain for short durations (< 2-min) have been theorized to improve D′. The purpose of the present study was to assess this in a group of moderately trained individuals. Methods Eighteen participants completed graded exercise testing (GXT), 40-m sprint testing and a 3-min all-out test (3MT) for running to determine key mechanistic and physiological parameters. Participants were randomly assigned into one of two groups based on intensity prescription (G 140% = 140% of critical speed [CS]), or time intervals (G 90-s = 90-s) to complete a twice-weekly training intervention for 6-weeks followed by re-assessment. Results No between-group differences were present either prior to or following the intervention. Substantial and meaningful improvements were detected during the post-intervention period for both groups for VO 2max 0.62 m/s; G 90-s : M = 0.46 m/s), D′ (G 140% : M = − 56.34 m; G 90-s : M = − 18.36 m), FI% (G 140% M = − 6.75%; G 90-s : M = − 4.38%) and maximal distance (G 140% : M = 49.67 m; G 90-s : M = 58.38 m).Conclusions The prescribed intensities and durations were insufficient to elicit improvements in D′. Improvements in D′ may be dependent on very short-duration intervals (i.e. < 60 to 90-s) at speeds exceeding 140% CS but below maximal sprint speed.

Paradigm Shift in Critical Speed Application and Modification for Shuttle Running: A Narrative Review

“…The final linear continuous test within this grouping is the 3-minute all-out test for running (3MT) [11,12]. The 3MT deviates substantially from the other tests in that (i) it requires all-out effort from the beginning of the test, (ii) provides both a submaximal threshold and maximal sprinting speed (iii) has had VȮ2 measured directly during testing allowing for both VȮ2max and VȮ2 kinetics assessment, and (iv) can be accurately used for programme prescription, training and monitoring [19,[36][37][38][39]. The concept of the 3MT originated from cycling research originally based on the hyperbolic relationship between power output and the sustainable duration of that workload (see Figure 1) [40][41][42].…”

“…requirements [37]. In addition to this, given the problematic nature of using absolute/fixed speed thresholds for match/training load monitoring across players (i.e., 5.5 m.s -1 for high speed running; 7 m.s -1 for sprinting), the results of 3MT can arguably provide more specific data to more specifically individualise these processes.…”

“…the athlete would need to run each bout at a speed of 4.26 m.s -1 [S = 0.7 130 m/120 s + 3.5 m.s -1 = 4.26 m.s-1 ]. Such interval prescription is based on experimental evidence that has shown that a D' depletion of 70% per bout, coupled with a 1:2 work-to-rest ratio, would allow for the successful completion of 4 bouts[37]. Towards the end of the 4 th bout the athlete would likely achieve their maximum heart rate (HRmax) coupled with an RPE of at least 18.…”

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

“…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 ].…”

“…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 ]. With CS as a measure defining the upper boundary of the heavy-intensity domain, exercising close to CS would be described as a “high-intensity” exercise [ 35 ].…”