Additionally, 4 of these athletes (participants 2, 4, 7 and 8) had an extensive history of altitude training utilizing both natural LHTH and simulated LHTL
over the preceding 3 to 5 years (2-3 camps annually).
Clark and others (Clark and others, 2004), in a study on 29 athletes (cyclists and triathletes) divided into a control group and two LHTL
groups (the first of these, permanent; the second spending 2 days in normaxia 4 nights, at an altitude of 2650 m, 9-10 hours/24 hours in normaxia), have not manifested any increase in the concentration of Hb despite a significant reduction of ferritin after 20 days of LHTL
Nonetheless, the LON protocol requires negligible time in comparison to LHTL, and it may be very appealing to athletes seeking to minimize time at altitude.
(40) who observed a decrease in salivary IgA and significant increases in salivary protein with LHTL altitude training.
En el grupo control ([T.sub.1]) histologicamente las muestras se observaron normales con excepcion de dos muestras que presentaron LHTL
, el resto de los grupos experimentales presentaron lesiones hepatotoxicas variando su grado de severidad.
In addition to their usual field hockey practice, all participants undertook six repeatedsprint training sessions (at least 36 h apart) under either normobaric hypoxia (LHTLH; ~3000 m simulated altitude or Fi[O.sub.2] ~14.5%, n = 9) or normoxia (LHTL
; near sea level or Fi[O.sub.2] 20.9%, n = 11), while residing under normobaric hypoxic conditions ([greater than or equal to] 14 h*[d.sup.-1] at 2800-3000 m simulated altitudes; Fi[O.sub.2] 14.5-14.2%), during a 14-d inseason training camp.
at natural altitude venues is often impractical (Hahn and Gore, 2001) because the travel involved to training venues may interfere with athletes' training schedules (Wilber, 2007).
Bonetti and Hopkins (2009) reported in their meta-analysis that the LHTL
protocol in natural conditions (hypobaric hypoxia) currently provides the best stimulus for enhancing endurance performance in elite and sub elite athletes, while some artificial protocols (normobaric hypoxia) are effective only in sub elite athletes.
Therefore, LHTH has been reconsidered for its inability to maintain training intensity for all athletes and research focus has moved towards the "Live High-Train Low" (LHTL
) method (Levine and Stray-Gundersen, 1997), which allows athletes to combine the physiological benefits of hypoxia (Brugniaux et al., 2006; Wehrlin et al., 2006), while maintaining training intensity.
In the past 15 years, numerous investigations have been conducted to examine the effects of Live High:Train Low (LHTL
) altitude training, where athletes live at moderate altitude (2000-3000 m) but train near sea-level, on subsequent sports performance [(Levine and Stray-Gundersen, 1997) for instance].