• Mid-expiratory flow versus FEV1 measurements in the diagnosis of exercise induced asthma in elite athletes

      Dickinson, J. W.; Whyte, Gregory P.; McConnell, Alison K.; Nevill, Alan M.; Harries, M. G. (BMJ Publishing, 2006)
      Backround: A fall in FEV1 of >10% following bronchoprovocation (eucapnic voluntary hyperventilation (EVH) or exercise) is regarded as the gold standard criterion for diagnosing exercise induced asthma (EIA) in athletes. Previous studies have suggested that mid-expiratory flow (FEF50) might be used to supplement FEV1 to improve the sensitivity and specificity of the diagnosis. A study was undertaken to investigate the response of FEF50 following EVH or exercise challenges in elite athletes as an adjunct to FEV1. Methods: Sixty six male (36 asthmatic, 30 non-asthmatic) and 50 female (24 asthmatic, 26 non-asthmatic) elite athletes volunteered for the study. Maximal voluntary flow-volume loops were measured before and 3, 5, 10, and 15 minutes after stopping EVH or exercise. A fall in FEV1 of >10% and a fall in FEF50 of >26% were used as the cut off criteria for identification of EIA. Results: There was a strong correlation between DFEV1 and DFEF50 following bronchoprovocation (r = 0.94, p = 0.000). Sixty athletes had a fall in FEV1 of >10% leading to the diagnosis of EIA. Using the FEF50 criterion alone led to 21 (35%) of these asthmatic athletes receiving a false negative diagnosis. The lowest fall in FEF50 in an athlete with a >10% fall in FEV1 was 14.3%. Reducing the FEF50 criteria to >14% led to 13 athletes receiving a false positive diagnosis. Only one athlete had a fall in FEF50 of >26% in the absence of a fall in FEV1 of >10% (DFEV1 = 8.9%). Conclusion: The inclusion of FEF50 in the diagnosis of EIA in elite athletes reduces the sensitivity and does not enhance the sensitivity or specificity of the diagnosis. The use of FEF50 alone is insufficiently sensitive to diagnose EIA reliably in elite athletes.
    • Prediction of VO2max from a new field test based on portable indirect calorimetry.

      Flouris, Andreas D.; Metsios, Giorgos S.; Famisis, Konstantinos; Geladas, Nikos; Koutedakis, Yiannis (Elsevier, 2010-01)
      We assessed the validity and reliability of the new 15m square shuttle run test (SST) for predicting laboratory treadmill test (TT) maximal oxygen uptake (VO(2 max)) compared to the 20 m multistage shuttle run test (MST) in 45 adult males. Thirty participants performed a TT and a SST once to develop a VO( 2max) prediction model. The remaining 15 participants performed the TT and MST once and the SST twice for cross-validation purposes. Throughout testing V O(2max) was determined via portable indirect calorimetry while blood lactate concentration was assessed at the fifth recovery minute. Comparisons of TT V O(2 max) (51.3+/-3.1 ml kg(-1)min(-1)) with SST measured (51.2+/-3.2 ml kg(-1)min(-1)) and predicted (50.9+/-3.3 ml kg(-1)min(-1)) V O(2 max) showed no differences while TT blood lactate was higher compared to SST (10.3+/-1.7 mmol vs. 9.7+/-1.7 mmol, respectively). In contrast, MST measured (53.4+/-3.5 ml kg(-1)min(-1)) and predicted (57.0+/-4.5 ml kg(-1)min(-1)) V O(2 max) and blood lactate (11.2+/-2.0 mmol) were significantly higher compared to TT. No test-retest differences were detected for SST measured and predicted V O(2 max) and blood lactate. It is concluded that the SST is a highly valid and reliable predictive test for V O(2 max).
    • Respiratory and immune response to maximal physical exertion following exposure to secondhand smoke in healthy adults

      Flouris, AD; Metsios, GS; Carrill, AE; Jamurtas, AZ; Stivaktakis, PD; Tzatzarakis, MN; Tsatsakis, AM; Koutedakis, Y; FAME Laboratory, Institute of Human Performance and Rehabilitation, Centre for Research and Technology, Thessaly, Greece. andreasflouris@gmail.com (Public Library of Science (PLoS), 2012-02-15)
      We assessed the cardiorespiratory and immune response to physical exertion following secondhand smoke (SHS) exposure through a randomized crossover experiment. Data were obtained from 16 (8 women) non-smoking adults during and following a maximal oxygen uptake cycling protocol administered at baseline and at 0-, 1-, and 3- hours following 1-hour of SHS set at bar/restaurant carbon monoxide levels. We found that SHS was associated with a 12% decrease in maximum power output, an 8.2% reduction in maximal oxygen consumption, a 6% increase in perceived exertion, and a 6.7% decrease in time to exhaustion (P<0.05). Moreover, at 0-hours almost all respiratory and immune variables measured were adversely affected (P<0.05). For instance, FEV 1 values at 0-hours dropped by 17.4%, while TNF-α increased by 90.1% (P<0.05). At 3-hours mean values of cotinine, perceived exertion and recovery systolic blood pressure in both sexes, IL4, TNF-α and IFN-γ in men, as well as FEV 1/FVC, percent predicted FEV 1, respiratory rate, and tidal volume in women remained different compared to baseline (P<0.05). It is concluded that a 1-hour of SHS at bar/restaurant levels adversely affects the cardiorespiratory and immune response to maximal physical exertion in healthy nonsmokers for at least three hours following SHS. © 2012 Flouris et al.