Calorie burn in outdoor sports: from hiking to ski touring

How do you measure whether cross-country skiing burns more calories than hiking? The answer is MET: Metabolic Equivalent of Task. One MET corresponds to energy expenditure at rest, around 1 kcal per kilogram of body weight per hour.

The rule of thumb is simple: kcal/h = MET × body weight (kg). If you weigh 80 kg and do a sport with a MET value of 8, you burn around 640 kcal per hour.

The most important source for MET values is the 2024 Compendium of Physical Activities, the third major update since 1993. The researchers screened more than 32,000 abstracts and extracted 2,356 energy-expenditure values from 701 studies. The result: 1,114 activities, 912 of them with MET values measured by calorimetry. Compared with the 2011 update, 303 new activities were added, including differentiated values for hiking at different gradients and with different pack weights for the first time.

In terms of calorie burn per hour alone, hiking sits in the middle of the pack. But on steep ascents with a heavy pack, it can match the figures of many intense sports. For the first time, the 2024 Compendium makes granular distinctions: flat terrain with a light daypack comes in at 3.5 MET, moderate cross-country hiking at 6.0 MET and mountain hiking with a 10+ kg backpack at 7.8 MET. Steep ascents (11–20% gradient) reach 8.8 MET.

As a rule of thumb, add 100–150 kcal per 100 metres of elevation gain to the baseline 350 kcal/h when climbing. A hut-to-hut hike with 1,000 metres of elevation gain can therefore quickly burn 800+ kcal, comparable to an hour of jogging.

Cross-country skiing is considered one of the most calorie-intensive sports of all, and for good reason: your arms and legs work at the same time. A comparative study by Scheiber et al. found that around 2.5 hours of alpine skiing are needed to match the energy expenditure of just one hour of cross-country skiing.

At a moderate pace (6–8 km/h), calorie burn is 595–680 kcal/h (70–80 kg). Those who have mastered the skating technique and push the pace can reach 13.3 MET, comfortably exceeding 1,000 kcal/h. In race mode (15.5–16.5 MET), peak values of more than 1,300 kcal/h have been documented.

Ski touring is among the most energy-intensive outdoor activities. The landmark study by Tosi, Leonardi & Schena provided the first quantitative description: at a self-selected speed on a 21% incline, energy expenditure is 10.6 J/kg/m, higher than for hiking or snowshoeing.

A moderate ascent burns 400–700 kcal/h. On intense climbs through deep snow and steep terrain, more than 1,000 kcal/h is realistic. One important factor is pace: increasing speed raises energy expenditure proportionally, with a 10% increase in pace costing around 3.2% more energy.

A sport’s MET value tells only half the story. Five factors can push your actual calorie burn up by as much as 55%, or leave it significantly lower than expected when conditions are favourable.

After intense training, your body does not simply stop burning calories. EPOC (excess post-exercise oxygen consumption) describes the increased oxygen consumption after exercise, while your body restores ATP and creatine phosphate stores, breaks down lactate and regulates body temperature.

Research shows a clear dependence on intensity: a light 30-minute session provides an additional 15–33 kcal. An intense 60-minute session at 70–75% VO₂max, on the other hand, delivers 76–165 kcal over up to 7.5 hours. The peak value: after a 45-minute intense cycling session, participants burned an additional 190 kcal over 14 hours.

For outdoor athletes, this means that a ski tour with alternating steep ascents, essentially natural interval training, produces a significantly greater afterburn effect than a moderate walk of the same duration.

How much energy does a long ski tour really require? Let’s work it out: