Table 1 Characteristics of the included studies
Study name | Country | Methods of simulating altitude | Simulated altitude | Intervention method | Intervention period | Time of IHT delivered | Sport event | Age | Sample size(male/female) |
|---|---|---|---|---|---|---|---|---|---|
Abellan 2005 [17] | Spain | Not available | Simulated altitude of 4,000 ~ 5,500 m | 3 h/day, 5 days/week | 4 weeks | Rest | Triathlon | Not available | 16(16/0) |
Ambrozy 2020 [18] | Poland | Altering FiO2 to 12.9% | Simulated altitude of 4,000 m | 1 h/day, 5 days/week | 6 weeks | Exercise | Boxing | 23.9 ± 2 0.97 | 30(30/0) |
Czuba 2011 [19] | Poland | Altering O2 of environment to 15.2% | Simulated altitude of 2,500 ~ 2,600 m | 1.5 ~ 2 h/day, 3 days/week | 3 weeks | Exercise | Cycling | 22.75 ± 3.14 | 20(20/0) |
Czuba 2013 [20] | Poland | Altering FiO2 to 15.2% | Simulated altitude of 2,500 m | 1.5 ~ 2 h/day, 3 days/week | 3 weeks | Exercise | Basketball | 22.0 ± 1.94 | 20(20/0) |
Gore 2006 [21] | Australia | US Air Force standard atmospheric tables | Simulated altitude of 4,000 ~ 5,500 m | 3 h/day, 5 days/week | 4 weeks | Rest | Running and swimming | 22.8 ± 8.04 | 27(16/11) |
Hendriksen 2003 [22] | Netherlands | Not available | Simulated altitude of 2,500 m | 2 h/day, 3 days/week | 9 days | Exercise | Triathlon | Not available | 24(24/0) |
Julian 2004 [23] | USA | Altering FiO2 to a range of 10.0–12.0% | Not available | 70 min/day, 5 days/week | 4 weeks | Rest | Running | 25.1 ± 3.23 | 17(14/3) |
Katayama 2003 [24] | Japan | Lowing barometric pressure to 432 torr | Simulated altitude of 4,500 m | 1.5 h/day, 3 days/week | 3 weeks | Rest | Running | 21.6 ± 2.93 | 12(12/0) |
Kime 2003 [25] | USA | Altering FiO2 to 15.0% | Simulated altitude of 2,500 m | 2 h/day, 3 days/week | 3 weeks | Exercise | Cycling | 17.0 ± 1.00 | 8(7/1) |
Meeuwsen 2001 [26] | Netherlands | Not available | Simulated altitude of 2,500 m | 2 h/day | 10 days | Exercise | Triathlon | 29.0(21 ~ 39) | 14(14/0) |
Morton 2005 [27] | UK | Altering FiO2 to 15.0% | Simulated altitude of 2,750 m | 30 min/day, 3 days/week | 4 weeks | Exercise | Team sports | 20.5 ± 0.80 | 16(16/0) |
Ramos-Campo 2015 [28] | Spain | Altering FiO2 to a range of 14.5–15.0% | Not available | 1 h/day, 2 days/week | 7 weeks | Rest | Triathlon | 27.7 ± 6.77 | 18(18/0) |
Rodríguez 2007 [29] | USA | Altering FiCO2 to less than 0.2% | Simulated altitude of 4,000 ~ 5,500 m | 3 h/day, 5 days/week | 4 weeks | Rest | Running and swimming | 22.5 ± 8.10 | 23(12/11) |
Roels 2005 [30] | France | Altering PiO2 of 100 mm Hg | Simulated altitude of 3,000 m | 114.9 min/week | 3 weeks | Exercise | Cycling and triathlon | 26.6 ± 6.25 | 19(NA) |
Roels 2007 [31] | France | Altering PiO2 of 100 mm Hg | Simulated altitude of 3,000 m | 1 ~ 1.5 h/day, 5 days/week | 3 weeks | Exercise | Cycling and triathlon | 24.3 ± 0.35 | 18(NA) |
Sanchez 2018 [32] | France | Altering FiO2 to a range of 10.6–11.4% | Simulated altitude of 5,000 ~ 5,500 m | 1 h/day, 3 days/week | 6 weeks | Exercise | Running | 28.5 ± 9.21 | 15(15/0) |
Tadibi 2007 [33] | Germany | Altering O2 of environment to a range of 10.0–11.0% | Simulated altitude of 5,200 ~ 5,900 m | 1 h/day, 7 days/week | 15 days | Exercise | Running | 27.7 ± 4.16 | 20(20/0) |
Truijens 2002 [34] | USA | Altering FiO2 to 15.2% | Simulated altitude of 2,500 m | 20 min/day, 7 days/week | 5 weeks | Exercise | Swimming | 28.8 ± 10.04 | 16(6/10) |
Zoretic 2014 [35] | Croatia | Altering EtCO2 of 45 mm Hg | Not available | 30 ~ 45 min/day, 3 days/week | 8 weeks | Exercise | Swimming | 15 ~ 25 | 16(16/0) |