Endurance exercise requires mental, as well as physical, strength for optimal performance. Whether it be during long, steady intervals during hard blocks of training in the chamber, or gruelling evening sessions of The Sufferfest, your head always needs to be in the game! If not, do-able efforts and intervals will feel that little bit harder than they should do and potentially cause early-onset fatigue. But what actually happens in our brain when we exercise at altitude?

A group of researchers have recently looked at this and published their data in a recent study. They took a group of well-trained cyclists through a self-paced time trial, which lasted until they each burnt 750 kJ, in both hypoxic (inspired oxygen level = 14.5%) and sea level conditions. During this, they measured the time taken to complete the time trial, as well as power output, SpO2, and alpha- and beta-activity of the brain throughout. For clarity, alpha-activity relates to sleep, but when this activity increases it is associated with mental readiness and attentiveness; additionally, beta-activity is linked to wakefulness and arousal.

The results showed that the participants found the time trial in hypoxia to be harder than the one at sea level, as expected and evidenced by a reduced power output (210 vs. 262 W, respectively) and greater time to complete the task (60 vs. 48 mins respectively) over the course of the exercise. Further, when the time trial began, alpha- and beta-activity increased and reduced overtime similarly in both hypoxia and at sea level.

So what does this mean?

Firstly, a time trial is more of a challenge when completed in hypoxic conditions compared to sea level. This is mainly due to a reduced oxygen content starving the body of its natural fuel source. But more importantly, there is no additional decrement in brain activity when one completes a time trial in hypoxia compared to sea level. Further, levels of readiness, attention and arousal are equally as high upon entering the chamber as they would when exercising at sea level. Therefore, there is no additional short term mental stress when completing sessions at altitude.

Now that the dark mornings and nights are kicking in, and motivation starts to sink towards Christmas, you now know that as long as you are ready in the mind, you are ready to go in one our classes or solos!

Study details

Periard et al., 2017. Acta Physiologica, doi: 10.1111/apha.12916.