Breath Intensity Monitoring PART ONE


When building training plans and during actual workouts, the determination of appropriate intensity for the workout is an area of much confusion with mountaineers. Some sports, such as running, rely on recent competitive performances to guide their intensity by using percentages of race pace. Rock climbers have grades (though these are admittedly flawed for a variety of reasons). But mountaineering doesn’t have an easy metric for determining speed as it relates to intensity because the effort it takes depends on factors that vary such as terrain, conditions, altitude, etc.

For mountaineers another metric of effort needs to be used. Several methods have been used with varying degrees of success:

Perception is handy and the old standby. By this we mean how does the exercise feel to you. What sensations are you noticing? Our body has many subtle and some not so subtle ways of giving us feedback. Both at a conscious and unconscious level our brain is interpreting all the feedback and creating a sensation of intensity. Unfortunately, individuals can have significantly different perceptions of the numerous different signals their brain is receiving.
Blood lactate monitoring, while accurate and effective, is not practical for day-to-day intensity monitoring. (Though technological advances in this area may be coming.) Given the chance, we use a lactate step test with individual athletes we are coaching. This gives us an accurate snapshot of that athlete’s lactate response on the day of the test. While reasonable generalizations can be inferred from these tests, the drawback is that it is hard to implement on a daily basis and unless the test is done frequently the effects of recent training, and recovery will not be accounted for in the daily training prescription going forward.

Blood lactate testing being done in the lab. Uphill Athlete, Steve House

Blood lactate testing being done in the lab. Credits: Uphill Athlete.

Heart rate zones offer an easy and concrete measure but they do so in an arbitrary and formulaic way that often does not represent each individual’s metabolic response to intensity. The result is false precision. In other words, the HR can be determined very accurately but how that relates to the metabolic effect of the exercise, which is what we care about as coaches and athletes, is not transmitted to the athlete in a usable way. A HR monitor will give precise, real time data measuring beats per minute down to single beat accuracy. But, can we really parse the metabolic processes to a fine level by measuring only HR? No. Unfortunately this is exactly the premise on which the theory and practice of HR monitoring is based and it is highly suspect if not outright false.

Ventilation (breathing rate and depth) provides real-time feedback on the metabolic process fueling the exercise at any given time and hence the intensity of that exercise. The drawback in the field (as opposed to a lab setting) is that we only have two ventilation markers of intensity. (Exercise physiologists call these the first and second ventillatory thresholds VT1 and VT2). These markers are fairly accurate in terms of their relaying information about the current metabolic state and they give meaningful, actionable, and instantaneous information to the athlete and coach. The biggest shortcoming of the ventillatory feedback is its reliance on athlete sensitivity and the lack of measurable and recordable electronically-generated data.

This ventilation metric can and should be used in conjunction with HR monitoring as the most meaningful prescription of intensity. It has been our experience that the formulaic 5-zone HR zone system often does not accurately relate an athlete’s personal metabolic response to training intensity. However, when combined with the ventillatory markers it can give a much more useful and real time look at which metabolic process is dominating ATP production at what heart rate. With careful observation an athlete can judge the actual intensity almost as well as if they were getting data from a gas exchange test or a blood lactate test in a lab (the gold standards). But this real time field test is portable and goes with the athlete in every workout.

Therefore an athlete self-monitoring by breath during training, uses the most meaningful and accurate picture of their current state of fitness. This is better than relying solely on either real-time HR monitoring or the occasional lactate test for day to day, in the field, assessment of intensity. In Part two of this article we’ll explain how to apply this powerful tool.

This is a series of three articles: