title: Repeated sprints with directional changes: do angles matter?
abstract: To examine whether performance, physiological and perceptual responses to repeated sprints including changes of direction are angle-dependent, twelve team-sport players performed (1) single 30-m sprints without or with two (45°, 90° or 135°) changes of direction and (2) repeated-sprint sequences matched for initial sprint time without (Line [6x30m]) or with (45° [6x28.0m], 90° [6x22.2m] or 135° [6x19.5m]) two changes of direction. For each sequence, mean sprint time (RS(mean)), peak heart rate (HR(peak)), blood lactate concentration (Δ[La](b)) and rating of perceived exertion (RPE) were recorded. Results show that performance, physiological and perceptual responses were angle-dependent. Compared with Line, RS(mean) was likely lower for 45˚ (-1.7%(90%CL:-3.5;0.1); chances for greater/similar/lower values of 1/23/76%, respectively) and possibly greater for 135˚ (+0.8%(90%CL:-0.6;2.3), 44/53/3%). HR(peak), Δ[La](b) and RPE were likely greater for Line compared with the three other protocols. RPE during 45˚ was greater than during 90˚(+14%(90%CL:8;19), 0/1/99%) and 135˚ (+11%(90%CL:1;22), 2/15/83%). The correlation coefficients describing the relationships between the four single 30-m sprints were <0.70; these for RS(mean) times were >0.70. Performance, physiological and perceptual response during repeated sprints with changes of direction are angle-dependent. However, unlike changes of direction speed, repeated-sprint ability with changes of direction is more likely to be a general quality.
authors.affiliation: Faculty of Sport Sciences, University of Picardie, Jules Verne, Laboratory of Exercise Physiology and Rehabilitation, Amiens, France. martin.buchheit@aspire.qa
authors.forename: Martin
authors.initials: M
authors.lastname: Buchheit
authors.forename: Bachar
authors.initials: B
authors.lastname: Haydar
authors.forename: Said
authors.initials: S
authors.lastname: Ahmaidi
mesh_terms: D000328:Adult; D054874:Athletic Performance; D006339:Heart Rate; D006801:Humans; D019344:Lactic Acid / Q000097:blood*; D008297:Male; D010465:Perception; D005082:Physical Exertion / Q000502:physiology*; D012420:Running / Q000502:physiology*; D055815:Young Adult
chemical_list: D019344:Lactic Acid