title: Effect of Intermittent Hypoxic Training Followed by Intermittent Hypoxic Exposure on Aerobic Capacity of Long Distance Runners.
abstract: Effects of intermittent hypoxic training (IHT) are still controversial and detraining effects remain uninvestigated. Therefore, we investigated (a) whether IHT improves aerobic capacity; (b) whether aerobic detraining occurs post-IHT; and (c) whether intermittent hypoxic exposure (IHE) at rest reduces a possible aerobic detraining post-IHT. Twenty eight runners (21 men/7 women; 36 ± 2 years; maximal oxygen uptake [V[Combining Dot Above]O2max] 55.4 ± 1.3 ml·kg·min) participated in a single-blinded placebo-controlled trial. Twice a week, 1 group performed 6 weeks of IHT (n = 11), followed by 4 weeks of IHE (n = 11) at rest (IHT+IHE group). Another group performed 6 weeks of IHT (n = 10), followed by 4 weeks of normoxic exposure (NE, n = 9) at rest (IHT+NE group). A control group performed 6 weeks of normoxic training (NT, n = 7), followed by 4 weeks of NE (n = 6) at rest (NT+NE group). Hematological and submaximal/maximal aerobic measurements were conducted in normoxia at pretraining, posttraining, and postexposure. Hemoglobin concentration did not change, but lactate threshold and running economy improved in all groups at posttraining (p ≤ 0.05 vs. pretraining). Ventilatory threshold, respiratory compensation point, and V[Combining Dot Above]O2max increased after IHT (IHT+IHE group: 7.3, 5.4, and 9.2%, respectively; IHT+NE group: 10.7, 7.5, and 4.8%; p ≤ 0.05 vs. pretraining), but not after NT (-1.1, -1.0, and -3.8%; p > 0.05 vs. pretraining). Such IHT-induced adaptations were maintained at postexposure (p > 0.05 vs. postexposure). In conclusion, IHT induced further aerobic improvements than NT. These additional IHT adaptations were maintained for 4 weeks post-IHT, regardless of IHE.
authors.affiliation: 1Graduate Program in Pharmacology, Federal University of São Paulo, São Paulo, Brazil; 2Olympic Center of Training and Research, São Paulo City Hall, São Paulo, Brazil; 3Department of Physiology, Federal University of São Paulo, São Paulo, Brazil; and 4Section of Human and Exercise Physiology, Faculty of Physical Education and Dance, Federal University of Goiás, Goiânia, Brazil.
authors.forename: Fernanda P
authors.initials: FP
authors.lastname: Nakamoto
authors.forename: Rafael K
authors.initials: RK
authors.lastname: Ivamoto
authors.forename: Marilia Dos S
authors.initials: Mdos S
authors.lastname: Andrade
authors.forename: Claudio A B
authors.initials: CA
authors.lastname: de Lira
authors.forename: Bruno M
authors.initials: BM
authors.lastname: Silva
authors.forename: Antonio C
authors.initials: AC
authors.lastname: da Silva
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology*; D000328:Adult; D005080:Exercise Test; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D000860:Hypoxia / Q000503:physiopathology*; D019344:Lactic Acid / Q000097:blood; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption / Q000502:physiology*; D012420:Running / Q000502:physiology*
chemical_list: D019344:Lactic Acid