@article{8645381,
  abstract     = {{Purpose

Intense exercise evokes a spleen contraction releasing red blood cells into blood circulation. The same mechanism is found after acute apnea, increasing hemoglobin concentration ([Hb]) by 2% to 5%. The aim of this study was twofold: [1] to identify the optimal apnea modalities to acutely increase [Hb] and [2] use these modalities to examine whether prerace apnea can improve a 3-km time trial (TT). Methods

In part 1, 11 male subjects performed 12 different apnea protocols based on three modalities: mode, frequency, and intensity. Venous blood samples for [Hb] were collected before, immediately, and 5 min after each protocol. In part 2, 12 recreationally active subjects performed 3-km cycling TT in three different conditions: apnea, control, and placebo, after a 10-min warm-up. Power output, HR, and oxygen uptake (V & x2d9;O-2) were continuously measured. Venous [Hb] was sampled at baseline, after warm-up, and before TT. Additionally, these subjects performed constant cycling at Delta 25 (25% between gas exchange threshold and V & x2d9;O-2 max) in two conditions (control and apnea) to determine V & x2d9;O-2 kinetics. Results

Although including one single apnea in the warming up evoked a positive change in [Hb] pattern (P = 0.049) and one single apnea seemed to improve V & x2d9;O-2 kinetics in constant submaximal cycling (tau: P = 0.060, mean response time: P = 0.064), performance during the 3-km TT did not differ between conditions (P = 0.840; apnea, 264.8 +/- 14.1 s; control, 263.9 +/- 12.9 s, placebo, 264.0 +/- 15.8 s). Average normalized power output (P = 0.584) and V & x2d9;O-2, HR, and lactate did not differ either (P > 0.05). Conclusions

These results suggest that potential effects of apnea, that is, speeding of V & x2d9;O-2 kinetics through a transient increase in [Hb], are overruled by a warming-up protocol.}},
  author       = {{Bouten, Janne and Colosio, Alessandro and Bourgois, Gil and Lootens, Leen and Van Eenoo, Peter and Bourgois, Jan and Boone, Jan}},
  issn         = {{0195-9131}},
  journal      = {{MEDICINE AND SCIENCE IN SPORTS AND EXERCISE}},
  keywords     = {{BREATH HOLDING,SPLEEN CONTRACTION,HEMOGLOBIN,OXYGEN UPTAKE KINETICS,PERFORMANCE,O-2 UPTAKE KINETICS,SPLEEN VOLUME,WARM-UP,HEMOGLOBIN CONCENTRATION,EXERCISE,HYPEROXIA,CONTRACTION,HYPOXIA}},
  language     = {{eng}},
  number       = {{5}},
  pages        = {{1116--1125}},
  title        = {{Acute apnea does not improve 3-km cycling time trial performance}},
  url          = {{http://dx.doi.org/10.1249/MSS.0000000000002236}},
  volume       = {{52}},
  year         = {{2020}},
}

Altmetric

View in Altmetric

Web of Science

Times cited: