The efficiency of “living high, training low” (LHTL) remains controversial, despite its wide utilization. This study aimed to verify whether maximal and/or submaximal aerobic performance were modified by LHTL and whether these effects persist for 15 days after returning to normoxia.

This double-blind, randomized, placebo-controlled trial examined the effects of 4 wk of resting exposure to intermittent hypobaric hypoxia (IHE, 3 h/day, 5 days/wk at 4,000–5,500 m) or normoxia combined with training at sea level on performance and maximal oxygen transport in athletes.

Over the past two decades, intermittent hypoxic training (IHT), that is, a method where athletes live at or near sea level but train under hypoxic conditions, has gained unprecedented popularity. By adding the stress of hypoxia during ‘aerobic’ or ‘anaerobic’ interval training, it is believed that IHT would potentiate greater performance improvements compared to similar training at sea level.

For nearly half a century, athletes have used “altitude training” to enhance sea level performance. Both altitude acclimatization and hypoxic exercise have been proposed as mediating this enhancement. However, hypoxic exercise impairs training quality and, in the absence of acclimatization, does not augment performance. The “living high-training low” model was therefore developed and demonstrated to be effective for athletes of all abilities.

Performing one or more altitude training stages, significantly improves the performance of the runners by triggering some physiological, hematologic changes in the athletes’ body favorable to performance increase.

The article discusses professional athletes' use of the Elevation Training Mask to simulate high altitudes during training to help regulate their breathing, focusing on football player Marshawn Lynch's use of the mask and the company's chief executive officer Casey Danford's claims that the mask allows athletes to build pulmonary resistance and strengthen their diaphragms.

Athletes have agreed for many years of the cardiovascular benefits of training at higher altitudes for endurance. Recently, advancements in training have given the rise to multiple options in altitude simulation tents or rooms and the most effective is the mask based hypoxicator system (Elevation Training Mask). Altitude training is called Hypoxic training which involves living and or training at a reduced oxygen level for the purpose of improved athletic performance or health benefits. The Mask reduces the partial pressure of oxygen while keeping the barometric pressure the same with the convenience of training at home or gym. Simulated Altitude Training showed improvements in EPO and red blood cells with performance gains in speed, strength, endurance and recovery.