A Sousa1,2, J L Viana3, J Milheiro4,5, V M Reis6, G P Millet7. 1. Research Center in Sports Sciences, Health Sciences and Human Development, CIDESD, University of Trás-Os-Montes and Alto Douro, Vila Real, Portugal. sousa.acm@gmail.com. 2. Research Center in Sports Sciences, Health Sciences and Human Development, CIDESD, University Institute of Maia, ISMAI, Maia, Portugal. sousa.acm@gmail.com. 3. Research Center in Sports Sciences, Health Sciences and Human Development, CIDESD, University Institute of Maia, ISMAI, Maia, Portugal. 4. CMEP Exercise Medical Center & SPA, Porto, Portugal. 5. Olympic Committee of Portugal, Lisbon, Portugal. 6. Research Center in Sports Sciences, Health Sciences and Human Development, CIDESD, University of Trás-Os-Montes and Alto Douro, Vila Real, Portugal. 7. ISSUL, Institute of Sport Sciences and Physical Education (ISSEP), University of Lausanne, Lausanne, Switzerland.
Abstract
PURPOSE: To test the hypothesis that interval-training (IHT) would be impaired by hypoxia to a larger extent than repeated-sprint training (RSH) and that dietary nitrate (NO3-) would mitigate the detrimental effect of hypoxia to a larger extent during IHT than RSH. METHODS: Thirty endurance-trained male participants performed IHT (6 × 1 min at 90%∆ with 1 min active recovery) and RSH (2 sets of 6 × 10 s "all-out" efforts with 20 s active recovery) on a cycle ergometer, allocated in one of three groups: normobaric hypoxia (~ 13% FiO2) + NO3- - HNO, n = 10; normobaric hypoxia + placebo - HPL, n = 10; normoxia (20.9% FiO2) + placebo - CON, n = 10. Submaximal oxygen uptake ([Formula: see text]O2), time spent above 90% of maximal [Formula: see text]O2 (≥ 90 [Formula: see text]O2max) and heart rate (≥ 90 HRmax) were compared between IHT and RSH sessions and groups. Additionally, mean power output (MPO), decrement score and % of power associated with [Formula: see text]O2max (%p[Formula: see text]O2max) in RSH sessions were analyzed. RESULTS: [Formula: see text]O2 at sub-maximal intensities did not differ between training protocols and groups (~ 27 ml kg-1 min-1). ≥ 90 HRmax was significantly higher in IHT compared to RSH session (39 ± 8 vs. 30 ± 8%, p = 0.03) but only in HNO group. MPO (range 360-490 W) and decrement score (10-13%) were similar between groups although %p[Formula: see text]O2max was significantly higher (p = 0.04) in CON (166 ± 16 W) compared with both HPL (147 ± 15 W) and HNO (144 ± 10 W) groups. CONCLUSION: IHT responses were neither more impaired by hypoxia than RSH ones. Moreover, dietary NO3- supplementation impacted equally IHT and RSH training responses' differences between hypoxia and normoxia.
PURPOSE: To test the hypothesis that interval-training (IHT) would be impaired by hypoxia to a larger extent than repeated-sprint training (RSH) and that dietary nitrate (NO3-) would mitigate the detrimental effect of hypoxia to a larger extent during IHT than RSH. METHODS: Thirty endurance-trained male participants performed IHT (6 × 1 min at 90%∆ with 1 min active recovery) and RSH (2 sets of 6 × 10 s "all-out" efforts with 20 s active recovery) on a cycle ergometer, allocated in one of three groups: normobaric hypoxia (~ 13% FiO2) + NO3- - HNO, n = 10; normobaric hypoxia + placebo - HPL, n = 10; normoxia (20.9% FiO2) + placebo - CON, n = 10. Submaximal oxygen uptake ([Formula: see text]O2), time spent above 90% of maximal [Formula: see text]O2 (≥ 90 [Formula: see text]O2max) and heart rate (≥ 90 HRmax) were compared between IHT and RSH sessions and groups. Additionally, mean power output (MPO), decrement score and % of power associated with [Formula: see text]O2max (%p[Formula: see text]O2max) in RSH sessions were analyzed. RESULTS: [Formula: see text]O2 at sub-maximal intensities did not differ between training protocols and groups (~ 27 ml kg-1 min-1). ≥ 90 HRmax was significantly higher in IHT compared to RSH session (39 ± 8 vs. 30 ± 8%, p = 0.03) but only in HNO group. MPO (range 360-490 W) and decrement score (10-13%) were similar between groups although %p[Formula: see text]O2max was significantly higher (p = 0.04) in CON (166 ± 16 W) compared with both HPL (147 ± 15 W) and HNO (144 ± 10 W) groups. CONCLUSION: IHT responses were neither more impaired by hypoxia than RSH ones. Moreover, dietary NO3- supplementation impacted equally IHT and RSH training responses' differences between hypoxia and normoxia.
Authors: Romeo B Batacan; Mitch J Duncan; Vincent J Dalbo; Patrick S Tucker; Andrew S Fenning Journal: Br J Sports Med Date: 2016-10-20 Impact factor: 13.800
Authors: Darren P Casey; Brandon D Madery; Timothy B Curry; John H Eisenach; Brad W Wilkins; Michael J Joyner Journal: J Physiol Date: 2009-11-30 Impact factor: 5.182
Authors: Stefan De Smet; Ruud Van Thienen; Louise Deldicque; Ruth James; Craig Sale; David J Bishop; Peter Hespel Journal: Front Physiol Date: 2016-06-14 Impact factor: 4.566