The below study found that there was a significant increase in Growth Hormone (GH) in subjects with excessive body weight, when undertaking hypoxic training.

This is significant because it is suggested that growth hormone deficiency is a characteristic of subjects with excessive body weight.

ABSTRACT:

The purpose of this work was to study the effects of acute hypoxia (hypoxic test, HT) and a course of interval hypoxic therapy (IHT) on the secretion of human growth hormone (GH), involved in the regulation of many metabolic processes. Twenty four normal subjects aged 35-55 years were examined; control (n = 18) received a course of placebo treatment. Plasma GH and glucose were measured during, before, and after HT. Initially plasma GH levels were decreased in subjects with excessive body weight (body weight index (BWI) >25 kg/m2), while in patents with normal weight ((BWI) <25 kg/m2) GH levels did not differ from the mean age specific values (5.5 +0.25 ng/ml). The level of GH level slightly increased in response to HT in subjects with BWI <25 kg/m2 and significantly increased in those with BWI >25 kg/m2, glucose levels did not change. After a course of IHT the levels of GH moderately Increased in subjects with BWI less than 25 kg/m2and sharply increased in those with BWI >25 kg/m2, glucose levels remaining unchanged. No changes in these parameters were observed in the placebo group. Henee, plasma GH concentrations increased after hypoxic exposure, the increase being particularly high in patients with excessive body weight. Hypoxic test reproduced larger reactions of GH, which were observed during long term adaptation to interval hypoxia as well