New research: Hunger hormones; hypoxia and that gremlin Ghrelin
One of the most interesting side effects you may feel after training with The Altitude Centre is that compared to training at sea level, you don’t feel very hungry afterwards.
A study published by the journal ‘Appetite’ investigated this and found that exposure to hypoxia of 14.5 per cent (2980m) reduced plasma concentration of ghrelin, the hormone that makes you feel hungry.
The study from the University of Bedfordshire investigated the effects of continuous moderate-intensity and high-intensity interval exercise in combination with short exposure to hypoxia on appetite.
Subjects comprising of 12 men completed four, 2.6-hour trials of moderate intensity and high intensity interval exercise at normoxia and hypoxia.
During moderate intensity exercise, the subjects ran for 50 minutes at 70 per cent of their altitude specific VO2 max, and during high intensity exercise, six sets of three minutes running at 90 per cent of their altitude VO2 max (with a seven minute warm-up and cool-down at 70 per cent VO2 max).
Exercise was completed after a controlled breakfast, and the participants ate another controlled, standardised meal (equivalent to 30 per cent of daily energy requirements) 45 minutes after exercise.
The results showed that participants’ appetite was lowered after hypoxic training compared to normoxia (sea level) due to lower concentrations of ghrelin found after hypoxic training, and this effect occurred during exercise, post-exercise, and for the full 2.6-hour trial period. Levels of ghrelin were also higher in high intensity interval exercise than moderate intensity exercise in hypoxic conditions during exercise.
These findings demonstrate that short exposure to hypoxia causes suppressions in appetite and ghrelin concentrations, and appetite responses to exercise do not appear to be influenced by the type of exercise completed.
This is great news for those of you fighting off the doughnut cravings at 2pm; our lunch time classes – high intensity interval cardio and Summit Circuits – may be able to help you manage a healthy eating plan.
For those of you heading to high altitudes for a trek or climb, we advise eating double whilst at altitude, even if you’re not feeling that hungry; book a Mountaineering Consultation for more information on summiting safely and successfully.