Table 1

Summary of current research findings relative to the use of intermittent hypoxic training (IHT) or repeated sprint training in hypoxia (RSH)

Author (year)	Participants	Design (number of training sessions, type, altitude and training content)	Groups	Statistically significant results (p<0.05)
Roskamm et al (1969)46	Untrained	24 over 4 weeks, cycling, 2250 m (N=6) or 3450 m (N=6; HH). 30 min aerobic training	IHT, N=12	10–17% VO_2max
Roskamm et al (1969)46	Untrained		INT, N=6	6% VO_2max
Terrados et al (1988)47	Elite cyclists	12–20 over 3–4 weeks, cycling, 2300 m (HH). Aerobic training and some intervals (15 s at 130% of aerobic peak power output)	IHT, N=4	33% PPO
Terrados et al (1988)47	Elite cyclists		INT, N=4	22% PPO
Martino et al (1995)48	Elite swimmers	Swim sprints at 2800 m (HH) during 21 days at altitude. No details available	IHT, N=20	−6% 100 m swim time, 34% PPO arm Wingate test
Martino et al (1995)48	Elite swimmers		INT, N=13	NS changes
Emonson et al (1997)49	Untrained	15 over 5 weeks, cycling, 2500 m (HH). 45 min at 70% of VO_2max	IHT, N=9	12% VO_2max
Emonson et al (1997)49	Untrained		INT, N=9	12% VO_2max
Katayama et al (1998)50	Untrained	10 over 2 weeks, cycling, 4500 m (HH). 30 min at 70% of normoxic VO_2max level	IHT, N=7	7% VO_2max
Katayama et al (1998)50	Untrained		INT, N=7	5% VO_2max
Bailey et al (2000)51	Runners	4 weeks at ∼2000 m (NH). Aerobic training, no details	IHT, N=18	15% VO_2max
Bailey et al (2000)51	Runners	4 weeks at ∼2000 m (NH). Aerobic training, no details	INT, N=14	5% VO_2max
Geiser et al (2001)52	Untrained	30 over 6 weeks, cycling, 3850 m (NH). 30 min at 77–85% of maximum heart rate	IHT, N=18	11% VO_2max, 17% 30 min TT mean PO
Geiser et al (2001)52	Untrained		INT, H=15	9% VO_2max, 19% 30 min TT mean PO
Karlsen et al (2002)53	Cyclists	9 over 3 weeks, cycling, 3000 m (NH). 120 min aerobic training	IHT, N=8	NS changes in VO_2max or 30 min TT
Karlsen et al (2002)53	Cyclists		INT, N=8	NS changes in VO_2max or 30 min TT
Hendriksen and Meeuwsen (2003)54	Triathletes	10 over 10 days, cycling, 2500 m (HH). 105 min aerobic training	IHT, N=8	5% PPO cycling Wingate test
Hendriksen and Meeuwsen (2003)54	Triathletes		INT, N=8	NS increase
Truijens et al (2003)55	Swimmers	15 over 5 weeks, swimming, 2500 m (NH). 12.5 min >100% VO_2max (30 s or 60 s bouts)	IHT, N=8	NS changes
Truijens et al (2003)55	Swimmers		INT, N=8	6% VO_2max
Ventura et al (2003)56	Cyclists	18 over 6 weeks, cycling, 3200 m (NH). 30 min aerobic training	IHT, N=7	NS changes in VO_2max or 10 min TT
Ventura et al (2003)56	Cyclists		INT, N=5	NS changes in VO_2max or 10 min TT
Morton and Cable (2005)16	Team-sport players	12 over 4 weeks, cycling, 2750 m (NH). 10×1 min at 80% of 2 min PPO	IHT, N=8	8% cycling Wingate test PPO, 7% VO_2max
Morton and Cable (2005)16	Team-sport players		INT, N=8	6.5% cycling Wingate test PPO, 8% VO_2max
Roels et al (2005)57	Cyclists and triathletes	14 over 7weeks, cycling, 3000 m (NH). 6–8×2–3 min at 100% of aerobic PPO	IHT, N=11	4% 10 min TT mean PO
			IHIT, N=11	9% VO_2max, 5% 10 min TT mean PO
			INT, N=11	5% 10 min TT mean PO
Roels et al (2007)58	Cyclists and triathletes	15 over 3 weeks, cycling, 3000 m (NH). 9×60 min at 60% VO_2max and 36 min with intervals of 2 min at 100% aerobic PPO (2 min bouts)	IHT, N=10	7% aerobic PPO
Roels et al (2007)58	Cyclists and triathletes		INT, N=9	7% aerobic PPO, 8% 10 min TT mean PO
Dufour et al (2006)59	Runners	12 over 6 weeks, running, 3000 m (NH). 24–40 min <VO_2max	IHT, N=9	5% VO_2max, 35% T_lim at vVO_2max
Dufour et al (2006)59	Runners	12 over 6 weeks, running, 3000 m (NH). 24–40 min <VO_2max	INT, N=9	NS changes
Hamlin et al (2010)22	Cyclists and triathletes	10 over 10 days, cycling, 3200–4400 m (NH). 90 min aerobic training followed by two 30 s Wingate tests	IHT, N=9	3% PO cycling Wingate test
Hamlin et al (2010)22	Cyclists and triathletes		INT, N=7	NS changes
Lecoultre et al (2010)60	Cyclists	12 over 4 weeks, cycling, 3000 m (NH). 4×12–18 min at 100–120% of aerobic PPO, 4×30–48 min <VO_2max and 4×100 min aerobic training	IHT, N=7	7% 40 km TT mean PO
Lecoultre et al (2010)60	Cyclists		INT, N=7	6% 40 km TT mean PO
Mao et al (2011)61	Active males	25 over 5 weeks, cycling, 2750 m (NH). 30 min aerobic training	IHT, N=12	16% VO_2max
Mao et al (2011)61	Active males		INT, N=12	10% VO_2max
Manimmanakorn et al (2013)23	Female team-sport players	15 over 5 weeks, knee flexion and extension, ∼4500 m (NH). 6 sets of low resistance knee extensions and flexions to failure with 30 s between sets	IHT, N=10	15% MVC3, 17% MVC30, 129% REPS201RM
Manimmanakorn et al (2013)23	Female team-sport players		INT, N=10	86% REP201RM
Holliss et al (2013)62	Active males	15 over 3 weeks, leg extension, 3000 m (NH). 10×60–70 s intense exercise with 20–30 s passive recovery. One leg IHT, the other leg INT	IHT, N=9	25% leg extension, incremental T_lim
Holliss et al (2013)62	Active males		INT, N=9	27% leg extension, incremental T_lim
Puype et al (2013)63	Moderately trained cyclists	18 over 6 weeks, cycling, 3000 m (NH). 4–9 sprints of 30 s interspersed with 4.5 min recovery at 50 W	RSH, N=10	6% sprint PO, 6% VO_2max, 6% 10 min PO, 7% LT4
			RSN, N=10	5% sprint PO, 6% VO_2max, 6% 10 min PO, NS
			CON, N=10	NS changes
Galvin et al (2013)64	Rugby players	12 over 4 weeks, treadmill running, 3500 m (NH). 10 sprints of 6 s interspersed with 30 s recovery	RSH, N=15	33% Yo-Yo Intermittent Recovery 1 test performance
Galvin et al (2013)64	Rugby players		RSN, N=15	14% Yo-Yo Intermittent Recovery 1 test performance
Faiss et al (2013)65	Moderately trained cyclists	8 over 4 weeks, cycling, 3000 m (NH). 3×5 all-out 10 s sprints interspersed with 20 s recovery at 120 W	RSH, N=20	6% sprint PO, 38% completed sprints in RSA test
			RSH, N=20	7% sprint PO, no change in completed sprints
			CON, N=10	NS changes

This table is limited to investigations with a group training in hypoxia (IHT, IHIT or RSH) and a group training in normoxia (INT or RSN). CON group without training present in two studies. Altitude described as either HH or NH. A significant difference between groups is shown in italics (p<0.05).
CON, control group; HH, hypobaric hypoxia; IHT, intermittent hypoxic training; IHIT, intermittent hypoxia interval training; INT, intermittent training in normoxia; LT4, power output corresponding to 4 mmol blood lactate; MVC3, peak maximum voluntary contraction in 3 s; MVC30, area under the peak 30 s maximal voluntary contraction curve; NH, normobaric hypoxia; NS, non-significant; PO, power output; PPO, peak power output; REPS201RM, repetitions at 20% of 1 repetition maximal load; RSA, repeated sprint ability test to exhaustion; RSH, repeated sprint training in hypoxia; RSN, repeated sprint training in normoxia; TT, time trial; T_lim, time to exhaustion; VO_2max, maximal oxygen uptake; vVO_2max, velocity associated with VO_2max.