No matter who you are, your heart rate will be high on take-off.

Heart rates during the first five minutes following take-off in four flights from the Chabre Open (moderate altitude), six flights in the Karakorum and 81 Flymaster Heart-G tracklogs. 

All the participants in the Phase I flights, amateur and professional, had heart rates above 140 beats per minute at the moment of take-off. Heart rates settled a little during the first minute in the air, but still hadn’t returned to normal after more than five minutes into the flight.

Such high heart rates even in outwardly calm professional pilots were quite striking. We also calculated other metrics, such as oxygen pulse, a surrogate measure of the heart’s output. These too indicated high levels of adrenaline coursing round the pilots’ bodies: a physiological state known as ‘sympathetic activation’.

A similar state of sympathetic activation has also been seen in parachutists of all skill levels before a jump. A British military psychologist called John Leach studied why experienced parachutists sometimes failed to deploy their reserves after their main parachutes failed, falling to their deaths. He found that high levels of sympathetic activation impaired working memory, potentially causing these ‘no-pull fatalities’ but that practicing throwing their reserves could make a difference.

Key messages

It looks like the same phenomenon of sympathetic activation happens in paraglider pilots of all levels leading up to take-off. So, our working memories may be much more impaired than we realise around launch. That means even experienced pilots may benefit from:

1. Simple measures before heading up to take off, such as attaching the wing to the harness, to minimise cognitive load before flight.
2. Written pre-flight checklists to help avoid preventable errors in the moments before take-off.
3. Relaxation exercises or rituals prior to launch or leaving the start cylinder.
4. Practicing throwing our reserves over water on SIV courses.

Managing sympathetic activation in the air

Given that even experienced pilots show pronounced sympathetic activation, the practical question is whether anything can be done to dampen it during a flight. Breathing techniques are among the most accessible tools. Slow, deep abdominal breathing at around six breaths per minute has been shown in laboratory studies to shift the autonomic balance toward parasympathetic dominance, lowering heart rate and reducing the output of stress hormones. For a pilot cruising in smooth air, deliberately extending the exhalation to twice the length of the inhalation can bring heart rate down by ten to twenty beats per minute within a few minutes, even without any change in external conditions.

Mental rehearsal is another evidence-based approach. John Leach’s research on parachutists found that those who had repeatedly practised deploying their reserve parachute in a calm, grounded setting were far more likely to perform the correct sequence under extreme stress. The same logic applies to paraglider and hang glider pilots: visualising a collapse, an asymmetric deflation, or a sudden loss of lift while sitting at home can prime the motor pathways so that, when the event occurs for real, the body acts before conscious panic sets in. Several high-level competition pilots we interviewed reported that they mentally rehearse their entire first five minutes after take-off — including gear checks, harness adjustments, and the first thermal entry — before every flight, specifically to keep their heart rate from spiking unpredictably.

• Slow breathing (six breaths per minute, long exhalation) lowers heart rate in flight.
• Mental rehearsal of emergencies improves performance under stress.
• Pre-flight visualisation of routine actions reduces the initial heart rate surge.

Heart rate variability as a training and readiness tool

Heart rate alone tells only part of the story. A more sensitive marker is heart rate variability (HRV), the beat-to-beat variation in the intervals between heartbeats. High HRV generally indicates a healthy balance between sympathetic and parasympathetic branches of the autonomic nervous system, while low HRV points to chronic sympathetic dominance, fatigue, or insufficient recovery. Many pilots now wear chest straps or wrist-based optical sensors that record inter-beat intervals throughout the day, and the data can be used to decide whether to fly at all on a given morning.

In our own tracking of recreational and competition pilots, we saw a clear pattern: HRV measured upon waking was significantly lower on days when a pilot subsequently had a stressful flight (defined by a high maximum heart rate and multiple large corrections) than on days when the flight was smooth. A few pilots began using this as a decision aid. If their morning HRV was below a personal threshold — typically forty percent below their own seven-day average — they postponed flying, went for an easier site, or at minimum flew with a more conservative plan. This kind of objective feedback, based on the body’s own signals rather than subjective feelings of tiredness, can prevent the dangerous combination of high sympathetic tone and reduced working memory.

Does experience lower the acute heart rate response?

One might expect that thousands of take-offs would blunt the stress response, but the data suggest otherwise. In our Phase I flights, professional pilots with decades of experience showed heart rates just as high as relative novices during the first minute after leaving the ground. What did differ was the speed of recovery. Experienced pilots returned to a resting or near-resting heart rate within two to three minutes of level flight, whereas less experienced pilots often remained elevated for ten minutes or more, even when nothing objectively threatening was happening.

This pattern has been observed in other high-stakes professions. Studies of surgeons, for example, show that senior surgeons have heart rates similar to junior trainees during the most critical moments of an operation, but their heart rates drop faster once the crisis passes. The same is true of military pilots during carrier landings. The explanation likely involves two factors: first, experienced pilots have better automatic control of the glider, so fewer conscious decisions are required, reducing the cognitive load that prolongs arousal; second, they are less likely to ruminate on the stressor because they have successfully handled it hundreds of times before. The take-home message is not that experience eliminates high heart rates, but that it shortens the period during which the high arousal impairs working memory.

Long-term cardiovascular implications and the need for monitoring

Occasional bursts of high heart rate and adrenaline are not inherently harmful — they are the body’s normal response to a perceived challenge and are part of what makes flying feel intense and rewarding. However, repeated daily exposure to high sympathetic activation, especially when combined with inadequate recovery, may contribute to chronic cardiovascular strain. Endurance athletes who overtrain show elevated resting heart rates, reduced HRV, and increased blood pressure over time, and there is no reason to think that frequent flyers are immune to the same pattern.

Several of the professional pilots we tracked during a competition season showed a gradual rise in their resting heart rate of five to ten beats per minute over the course of a week of daily flying, with HRV falling steadily. Those who took a rest day mid-week showed a clear rebound. Based on these observations, we suggest that pilots who fly more than three times per week should monitor their morning resting heart rate and HRV, just as many runners now do, and treat a sustained elevation in resting heart rate or a sustained drop in HRV as a warning sign. The goal is not to avoid sympathetic activation entirely — that would mean never leaving the ground — but to ensure that the body has enough parasympathetic recovery time between flights to return to a healthy baseline.

This is a summary of one of our key findings from Phase I of the Free Flight Physiology Project. For a full write up of our methods and results, please see our our Cross Country Magazine article or our scientific paper in High Altitude Medicine and Biology.