Pomoca's journey to Patrouille des Glaciers, article 1/6


When planning your training for a specific race, the first thing you need to do is to break down your season in periods, mesocycles and cycles. A cycle will typically last 4 weeks. A mesocycle is the equivalent of a given succession of cycles and a period is the equivalent of a given succession of mesocycles.


Starting from December through April, we have 20 weeks to prepare the race. The first mesocycle will focus on general preparation. It will be made of two cycles (base 1 and base 2) each consisting of 4 weeks. The total charge of training will increase progressively for 3 weeks and will end with a recovery week. Low intensity is key to build a solid base. The second mesocycle will focus on specific preparation. It will  be made of three cycles (build 1, build 2 and build 3) of 4 weeks each except for build 3. Volume will progressively decrease while intensity will raise. We will then end the preparation with two weeks of tapering where volume will fall but we’ll keep a certain intensity.



The training volume represents the “how much” you’ve done, without taking the intensity into account. In skimo, it can best be expressed in duration (hours) or in vertical meter gains (D+)


Training intensity represents the “how hard did you push”, without taking volume into account. Different models exists to quantify the intensity of a given training session and most of them need  training zones to be precisely measured. The only subjective measure you can use is Borg’s scale and is expressed in RPE (Rate of Perceived Exertion).


Training load takes into account both volume and intensity. It is an important tool for tracking your training through the whole season. It can be expressed in many units depending on the method you use. A common one is the Foster method (load = duration x RPE) which is great if you’re using RPE to quantify intensity


Training and the physiological stress induced in the organism facilitate the body's adaptation and consequent enhancement of performance. Nevertheless, it is crucial to acknowledge that recovery is imperative for the restoration of energy reserves depleted during each training session. Effective management of the equilibrium between stress and recovery is conducive to achieving a supercompensation effect. Exemple 1 below shows a positive training cycle where performance level will drop after a training stimulus and will only raise after a complete recovery, thus showing the supercompensation effect. On the contrary, exemple 2 depicts a negative training cycle, where recovery is incomplete. Despite training stimuli, the progression is negative.


This balance can be achieved through the principle of polarized training. This training principle is based on a relatively straightforward rule to remember, namely the 80-20 rule.
80% of the training should be performed ≤ Ventilatory Threshold 1 (VT1). The remaining 20% should be performed ≥ Ventilatory Threshold 2 (VT2). For an athlete training four times a week, it would be prudent to incorporate three low-intensity training sessions and one interval training session. Excessive high-intensity training could yield counterproductive results.
VT1 and VT2 are physiological values determined through a standardized laboratory exercise test. However, a useful practical indicator for VT1 is a pace at which a conversation can be comfortably maintained without breathlessness. VT2 corresponds to a pace that you can sustain for approximately 30 to 60 minutes.



The Ventilatory Threshold 1 (VT1), represents the point at which exercise intensity becomes significantly more demanding from a cardiorespiratory perspective. This typically corresponds to a moderate to sustained heart rate and effort intensity  (RPE). VT1 corresponds to a clear raise of  ventilation (VE) and of the VE/VO2 ratio. The VO/VCO2 ratio, however, stays still. VT1 occurs at 40-60% of VO2 max or above, depending on your training level.


The Ventilatory Threshold 2 (VT2),  represents the point beyond which the effort becomes highly intense from a cardiorespiratory standpoint, and the athlete reaches their maximum effort capacity. This typically corresponds to a high heart rate and RPE. VT2 corresponds to a second clear raise of VE and of VE/VO2, this time along with a clear raise of the VE/VCO2 ratio. The ability to sustain this effort is limited. It occurs at 60% (sedentary) - 90% (endurance-trained athletes) of VO2max


 VO2max represents the maximum amount of oxygen that the body can absorb, transport, and utilize at the cellular level during physical activity. The measurement of VO2max is usually conducted through a treadmill or ergocycle exercise test, during which the exercise intensity progressively increases. VO2max is reached when oxygen consumption ceases to increase despite increasing exercise intensity, indicating the point at which the cardiorespiratory system reaches its limits.

To learn more about periodization or polarized training:

Issurin, V. (2008). Block periodization versus traditional training theory: a review. Journal of sports medicine and physical fitness, 48(1), 65.

Issurin, V. (2010). New horizons for the methodology and physiology of training periodization. Sports medicine, 40, 189-206.

Seiler, S., & Kjerland, G. Ø. (2006). Quantifying training intensity distribution in elite endurance athletes: is there evidence for an “optimal” distribution?. Scandinavian journal of medicine & science in sports, 16(1), 49-56.

Seiler, S., & Tønnessen, E. (2009). Intervals, thresholds, and long slow distance: the role of intensity and duration in endurance training. Sportscience, 13.