Estimating Energy Cost while Hiking

It's something many people are interested in knowing. How many calories are you really burning while hiking?

In reality, highly accurate estimations are specific to the individual, but there are some basic properties to start with. So, we'll start laying at least a foundation now.

A paper from the Journal of Applied Physiology has looked at how energy expenditure is affected by the slope (grade) while walking (and running). You can read the full study with the link provided. Basically, they put people on a treadmill at different gradients and measure how much oxygen they are consuming. From that, they find an equation relating the relative work performed at a given grade relative to the work performed while walking on flat ground.

Concept: Oxygen Consumed ~ Work ~ Calories Burned

Does Hiking Pole Weight Matter?

People are always looking for the newest, most advanced technology in any area of interest. Hiking, of course, is included. And people love to get the lightest poles available (as long as they don't break!). But does weight matter?

One study compared hiking poles of three different weights. and found that muscle activity (electromyography) of the biceps brachii and anterior deltoid increased with increasing pole weight. The anterior deltoid assists in flexion of the shoulder (brining your upper arm from your side to in front of you horizontally) and also is needed to resist gravity and the weight of your arm. With a hiking pole with increasing weight, this muscle should increase in activation. The biceps brachii (or just your biceps) work to flex your elbow, and again will be increasingly activated as more load is placed on the hand as your arm is out in front of you.

Lightweight Leki Poles are nice, but is it worth it?

Food / Fluid Intake & Improving Hiking Performance

This article gives a nice overview of some of the things people can do to improve endurance performance right away. I am not promoting Hammer Nutrition - I'm not even sure I've ever had anything made by them - but the article is good.

When preparing for a long, strenuous trek, following such tips about hydration and proper food consumption will undoubtedly make your effort easier and make you feel better doing it.

Vertical Ascent Rate

While we just looked at an example of how walking speed changes with change in trail steepness, it is also interesting to look at how vertical ascent rate (VAR) changes with trail steepness.


Of course, I think most people would generally hypothesize that VAR increases as the grade increases, since a larger % of energy will be spent on vertical movement. I would also hypothesize that above some grade (perhaps 60-70%), VAR would begin to decrease - I am thinking about loss of friction, change in terrain, and change in biomechanical efficiency - but that is simply conjecture at this point.


We will look at only one exemplar hike (Big Iron again) which is suitable because of the breadth of gradients encountered and I was attempting to hike at a constant pace. Below is a plot of VAR vs grade % (this time I multiplied by 100% so it makes more sense, like 15% grade on a treadmill).

How is Hiking Speed Affected by Steepness? A GPS Graphical Analysis

The short answer is we slow down as the trail gets steeper. Yes, I know, pretty obvious.

But how much? And what steepness / speeds are equivalent...is hiking a 10% grade fire road fast the same exertion as hiking up a 30 % grade mountain at 2 mph?

This is one of many things interesting to look at through the experimental data that a GPS device can collect. Take a look at the graph below, which shows my hiking speed versus the steepness of the trail while on a hike up Iron Mountain in the San Gabriels.

Energy Systems Part 2 - Aerobic Exercise

We previously went over some basics of anaerobic exercise, now on to the aerobic portion.

3. Glycolysis - Aerobic
The burning of glycogen using oxygen can last much longer than without...but how long? Well, it's going to be directly related to how much glycogen you have stored in your muscles. So when you workout, you need to eat carbohydrates to replenish these storages. If you don't, you will feel fatigued, as your body can't produce energy at the rate you are used to. That's why you'll see people eating all sorts of sugary stuff when doing multi-hour endurance activities. Gatorade came to signficance partly due to showing that by giving carbohydrate calories to people during exercise, the participants could perform the exercise for longer.

Energy Systems Part 1 - Anaerobic Exercise

We will start backwards. When we hike (or run) we move our limbs in desired motions and speeds. To get the desired movements, we need our muscles to contract. Muscles cannot contract without having energy available. So we need to get energy to the muscles.

Where does the energy come from, you say? Well, it depends on the energy demands of the muscle. Compare walking at 3 mph on a flat terrain to walking 3pmh on a steep trail and running 6 mph on a steep trail. Wouldn't you agree the energy demands are different? In the 6 mph case, there is a high energy demand and it is probable that this pace could not be kept up for long. High energy demand exercise is considered anaerobic exercise. This basically means that the energy for the muscles is produced without using oxygen, and that the energy supply is quite limited - only lasting for a few minutes. But because the energy can be created without oxygen, a lot of it can be produced quickly, so fast movements that last up to 3 minutes will rely on this source.

If you try to run up a 25% grade, you'll be quickly using up your anaerobic energy