IntroductionThe ergogenic effects of respiratory alkalosis induced by prior voluntary hyperventilation (VH) are controversial. This study examined the effects of prior VH on derived parameters from the 3-min all-out cycling test (3MT). Methods Eleven men (V ̇O2max = 46  8 mLkg -1 min -1 ) performed a 3MT preceded by 15-min of rest (CONT) or voluntary hyperventilation (V ̇E = 38  5 Lmin -1 ) with PETCO2 reduced to 21  1 mmHg (HYP). End-test power (EP; synonymous with critical power) was calculated as the mean power output over the last 30-s of the 3MT, and the work done above EP (WEP; synonymous with W) was calculated as the power-time integral above EP. Results At the start of the 3MT, capillary blood PCO2 and [H + ] were lower in HYP (25.2  3.0 mmHg, 27.1  2.6 nmolL -1 ) than CONT (43.2  2.0 mmHg, 40.0  1.5 nmolL -1 ) (P < 0.001). At the end of the 3MT, blood PCO2 was still lower in HYP (35.7  5.4 mmHg) than CONT (40.6  5.0 mmHg) (P < 0.001). WEP was 10% higher in HYP (19.4  7.0 kJ) than CONT (17.6  6.4 kJ) (P = 0.006), whereas EP was 5% lower in HYP (246  69 W) than CONT (260  74 W) (P = 0.007). The ΔWEP (J•kg -1 ) between CONT and HYP correlated positively with the PCO2 immediately before the 3MT in HYP (r = 0.77, P = 0.006). Conclusion These findings suggest that acid-base changes elicited by prior voluntary hyperventilation increase WEP but decrease EP during the all-out 3MT.

IntroductionExercise-induced bronchoconstriction (EIB) is a prevalent condition in athletes. EIB screening studies identify many athletes with undiagnosed EIB. Moreover, there is a poor relationship between EIB and dyspnea symptoms recalled from memory.PurposeThis study investigated: (I) the prevalence of EIB in British university field hockey athletes; (II) the effect of sex and diagnostic criteria on EIB prevalence; and (III) the association between EIB and contemporaneous dyspnea symptoms.Methods52 field hockey athletes (age: 20 ± 2 years; height: 173 ± 9 cm; body mass: 72 ± 10 kg; male = 31; female = 22) completed a eucapnic voluntary hyperpnea (EVH) test with multi-dimensional dyspnea scores measured 3–10 mins post-EVH. A test was deemed positive (EIB+) if a fall index (FI) ≥10% in FEV1 occurred at two consecutive time points post-test (FIATS). Two further criteria were used to assess the effect of diagnostic criteria on prevalence: FI≥10%, determined by a pre-to-post-EVH fall in FEV1 of ≥10% at any single time-point; and FI≥10%−NORM calculated as FI≥10% but with the fall in FEV1 normalized to the mean ventilation achieved during EVH.ResultsEIB prevalence was 19% and greater in males (30%) than females (5%). In EIB+ athletes, 66% did not have a previous diagnosis of EIB or asthma and were untreated. Prevalence was significantly influenced by diagnostic criteria (P = 0.002) ranging from 19% (FIATS) to 38% (FI≥10%−NORM). Dyspnea symptoms were higher in EIB+ athletes (P ≤ 0.031), produced significant area under the curve for receive operator characteristics (AUC ≥ 0.778, P ≤ 0.011) and had high negative prediction values (≥96%).ConclusionOverall, 19% of university field hockey athletes had EIB, and most were previously undiagnosed and untreated. EVH test diagnostic criteria significantly influences prevalence rates, thus future studies should adopt the ATS criteria (FIATS). Contemporaneous dyspnea symptoms were associated with bronchoconstriction and had high negative prediction values. Therefore, contemporaneous dyspnea scores may provide a useful tool in excluding a diagnosis of EIB.