• Validity of claims for efficacy of the O2 and CO2 “tolerance training tables”, and associated risks

      Barry-Wilson, Samantha (University of Bedfordshire, 2010-03)
      Both physical and apneic (voluntary breath hold) training have been shown to prolong apneic time. One of the most readily available training developments are the 'tolerance training tables' (TTT). These are a series of breath-hold and breathing periods intended to elicit low O2 or high CO2 levels in a progressive fashion. Developments of the tables have been made on the basis of anecdotal evidence. These tables are yet to be formalised and validated or risk assessed During a familiarisation session, participants were required to attempt a maximal breath-hold (MaxBH) time; breath-hold and breathing period ratios for the 'tables' were derived from this MaxBH. During the investigation participants were required to attend two counterbalanced weeks (C02 and O2) of testing. Expiratory gases were monitored using breath-by-breath analysis (Cortex Biophysics, Liepzig, Germany) to observe any intervention derived blood gas changes. Blood oxygen saturation levels were monitored non-invasively via pulse oximetry (LifePulse, LP28, HME Ltd., England [extremity]; Avant 2120, Nonin, USA [ear]). Empirical trends in O2 values were seen within the O2 TTT. O2 values prior to breath-hold displayed a pattern of progressive increase over the series of eight breath-holds with a controlled 3-breath breath-up strategy. O2 values post breath-hold displayed a pattern of progressive reduction over the series of eight breath-holds, evidencing the increasing metabolism of O2 during apnea. Despite this, a univariate ANOVA indicated no statistical significance between the eight phases of breath-hold (e.g. p = 0.134). CO2 values indicated no empirical trends and no statistical significance prior to, or following, breath-hold. CO2 values displayed relatively unchanged values following the series of eight breath-holds. Comparisons between O2 and CO2 protocols indicated no statistical difference.