title: Cardiorespiratory and cardiac autonomic responses to 30-15 intermittent fitness test in team sport players.
abstract: The 30-15 Intermittent Fitness Test (30-15IFT) is an attractive alternative to classic continuous incremental field tests for defining a reference velocity for interval training prescription in team sport athletes. The aim of the present study was to compare cardiorespiratory and autonomic responses to 30-15IFT with those observed during a standard continuous test (CT). In 20 team sport players (20.9 +/- 2.2 years), cardiopulmonary parameters were measured during exercise and for 10 minutes after both tests. Final running velocity, peak lactate ([La]peak), and rating of perceived exertion (RPE) were also measured. Parasympathetic function was assessed during the postexercise recovery phase via heart rate (HR) recovery time constant (HRR[tau]) and HR variability (HRV) vagal-related indices. At exhaustion, no difference was observed in peak oxygen uptake VO2peak), respiratory exchange ratio, HR, or RPE between 30-15IFT and CT. In contrast, 30-15IFT led to significantly higher minute ventilation, [La]peak, and final velocity than CT (p < 0.05 for all parameters). All maximal cardiorespiratory variables observed during both tests were moderately to well correlated (e.g., r = 0.76, p = 0.001 for [latin capital VO2peak). Regarding ventilatory thresholds (VThs), all cardiorespiratory measurements were similar and well correlated between the 2 tests. Parasympathetic function was lower after 30-15IFT than after CT, as indicated by significantly longer HHR[tau] (81.9 +/- 18.2 vs. 60.5 +/- 19.5 for 30-15IFT and CT, respectively, p < 0.001) and lower HRV vagal-related indices (i.e., the root mean square of successive R-R intervals differences [rMSSD]: 4.1 +/- 2.4 and 7.0 +/- 4.9 milliseconds, p < 0.05). In conclusion, the 30-15IFT is accurate for assessing VThs and VO2peak, but it alters postexercise parasympathetic function more than a continuous incremental protocol.
authors.affiliation: Faculty of Sport Sciences, Laboratory of Exercise Physiology and Rehabilitation, University of Picardie Jules Verne, Amiens, France. martin.buchheit@u-picardie.fr
authors.forename: Martin
authors.initials: M
authors.lastname: Buchheit
authors.forename: Hani
authors.initials: H
authors.lastname: Al Haddad
authors.forename: Grégoire Paul
authors.initials: GP
authors.lastname: Millet
authors.forename: Pierre Marie
authors.initials: PM
authors.lastname: Lepretre
authors.forename: Michael
authors.initials: M
authors.lastname: Newton
authors.forename: Said
authors.initials: S
authors.lastname: Ahmaidi
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology*; D000704:Analysis of Variance; D001341:Autonomic Nervous System / Q000502:physiology*; D005080:Exercise Test / Q000379:methods*; D006339:Heart Rate; D006801:Humans; D008297:Male; D010806:Physical Education and Training / Q000379:methods; D010809:Physical Fitness / Q000502:physiology; D011336:Probability; D020127:Recovery of Function; D012119:Respiration; D012143:Respiratory Physiological Phenomena; D012680:Sensitivity and Specificity; D013177:Sports / Q000502:physiology*; D013997:Time Factors; D055815:Young Adult