Six weeks of static apnea training does not affect Hbmass and exercise performance

Acute apnea is known to induce decreases in oxyhemoglobin desaturation (SpO(2)) and increases in erythropoietin concentration ([EPO]). This study examined the potential of an apnea training program to induce erythropoiesis and increase hematological parameters and exercise performance. Twenty-two male subjects were randomly divided into an apnea and control group. The apnea group performed a 6-wk apnea training program consisting of a daily series of five maximal static apneas. Before and after training, subjects visited the lab on 3 test days to perform 1) a ramp incremental test measuring (V)over dotO(2peak), 2) CO-rebreathing for Hbmass determination and a 3-km time trial, and 3) an apnea test protocol with continuous finger SpO(2) registration. Venous blood samples were drawn before and 180 min after the apnea test for analysis of [EPO]. Minimal SpO(2) reached during the apnea test protocol was 91 +/- 7% pre and 82 +/- 7% post apnea training. The apnea test protocol did not elicit an acute increase in [EPO] (P = 0.685) before nor after the training program. Consequently, resting [EPO] (P = 0.170), Hbmass (P = 0.134), (V)over dotO(2peak) (P = 0.796), and 3-km cycling time trial performance (P = 0.509) were not affected either. The apnea test and training protocol, consisting of five maximal static apneas, did not induce a sufficiently strong hypoxic stimulus to cause erythropoiesis and therefore did not result in an increase in resting [EPO], Hbmass, (V)over dotO(2peak), or time trial performance. Longer and/or more intense training sessions inducing a stronger hypoxic stimulus are probably needed to obtain changes in hematological and exercise parameters.

Automated summary

The study found that the apnea test and training protocol, including maximal static apneas, did not provide a strong enough hypoxic stimulus to induce erythropoiesis and improve exercise performance. Longer or more intense training sessions may be necessary to see changes in hematological and exercise parameters.