CARDIORESPIRATORY AND CARDIAC AUTONOMIC RESPONSES TO 30-15 INTERMITTENT FITNESS TEST IN TEAM SPORT PLAYERS

Buchheit, M, Al Haddad, H, Millet GP, Lepretre, PM, Newton, M, and Ahmaidi, S. Cardiorespiratory and cardiac autonomic responses to 30-15 Intermittent Fitness Test in team sport players. J Strength Cond Res 23(1): 93-100, 2009-The 30-15 Intermittent Fitness Test (30-15(IFT)) 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 30-15(IFT) 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 ((V) over doto(2)peak), respiratory exchange ratio, HR, or RPE between 30-15(IFT) and CT. In contrast, 30-15(IFT) 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 (V) over doto(2)peak). Regarding ventilatory thresholds (VThs), all cardiorespiratory measurements were similar and well correlated between the 2 tests. Parasympathetic function was lower after 30-15(IFT) than after CT, as indicated by significantly longer HHR tau (81.9 +/- 18.2 vs. 60.5 +/- 19.5 for 30-15(IFT) 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 30-15(IFT) is accurate for assessing VThs and (V) over doto(2)peak, but it alters postexercise parasympathetic function more than a continuous incremental protocol.