Weighted Training for Mountain and Trail Athletes
Why and Why Not?
By Eric Carter, PhD.
With contributions by Ryan Kerrigan BSc. & Matt Paul.
Adding weight to endurance training sessions, either using a weight vest or a loaded backpack, is an important component of training for many athletes. Weighted training doesn’t work for everyone however, and may not be appropriate depending on the terrain characteristics and distance of the event the athlete is training for.
Weighted training is primarily a method of developing muscular endurance. That is, the ability to repeatedly make movements requiring greater force than what normally would be considered endurance movement. Below we’ll discuss what events weighted training may be beneficial for and why. Additionally, we outline how a mountain endurance athlete can add this type of training into their routine.

Who doesn’t weighted training work for?
Trail runners, especially in the sub-ultra distance, very rarely need to develop their muscular endurance and will therefore see little value in weighted training. Cardiovascular fitness is the limiting factor for these athletes – you can’t run faster because your breathing limits you, not the ability of your muscle to generate force.
Adding weighted training while trail running on flat/undulating terrain won’t improve that training session despite the common misconception that just because it’s harder, it will be better. The extra weight will increase cardiovascular output, something that we can also accomplish by simply running faster. This will also have the detrimental effect of requiring adaptation in running form to handle the additional weight. Finally, it will place greater forces on your joints, increasing injury risk.
There are situations, at the end of an ultra for example, where the muscle’s ability to generate force is diminished, often accompanied by pain and cramping. This is not a limitation of muscular endurance but rather the literal destruction of muscles contractile proteins. With our athletes, we refer to the ability to forestall or prevent the destruction of muscle as resilience. Another example of a lack of resilience is when you add in excessive downhill running suddenly and experience similar lack of strength, cramping, etc. Resilience is best acquired by sport specific training – endurance training approaching the length at which you wish to compete, or on terrain that replicates the descents you might encounter. We’ll tackle this topic in another article!

Who does weighted training work for?
Imagine doing a plyo-box step-up in the gym: it’s a strength exercise! If your sport requires you to do the equivalent of many repeated box steps (especially with added weight), developing muscular endurance will be a useful component of your training program. In these situations, output is not limited by cardiovascular fatigue but by local muscular fatigue and training muscular endurance will delay onset.
Weighted training is best utilized by alpinists and ski mountaineers. If your activity requires you to either 1) carry a pack with weight – such as an expedition climber; or 2) take repeated steps that are greater than the normal running range of motion – like during ski touring (and some mountain runners – see below), you’ll see benefit from training with extra weight.
An uphill specific runner, for example someone who competes in mountain running or vertical kilometre events, may require the ability to make unusually large step ups while competing. Very rough trails with many big step ups, especially in a long continual uphill, will tax muscular endurance. These athletes may benefit from specific weighted training but care is required in the design and execution of the training to avoid affecting technique.
How to use weighted training?
It might be tempting for an expedition climber or ski mountaineer to do all their training with weight; however, it’s useful to do a significant portion of endurance training unweighted. Use weight very specifically to develop muscular endurance just like you use strength exercises specifically in the gym.

Here are some important ideas to keep in mind if you decide to add weighted training to your plan:
- Weighted training is best done on a steep uphill climb that requires you to hike rather than run. If you’re running, you risk the detrimental effects mentioned above.
- The load doesn’t need to be excessive. My rough calculation to determine weight is to first know your normal Z1 intensity hiking speed for a particular uphill climb. Add enough weight that you’re moving at roughly the same speed but working at a Z3 intensity. This will take a bit of experimenting and maybe a small adjustment in pace but should be fairly straightforward. For me, it’s about 10kg that will push me from Z1 to Z3.
- Tempo/Zone 3 work will be the most useful. Depending on baseline fitness, you may only tolerate 10 min of loaded climbing. An elite athlete should be able to handle continuous 30-60 min sessions.
- Zone 4/5 work will be too hard to maintain technique so should be avoided. These high-intensity intervals are better done unweighted. If you want to develop pure strength, do it in the weight room with more weight and better control.
- Weighted training will have a significant impact on your legs. Plan sufficient recovery between a weighted session and a normal intensity session (or a race)! A solid aerobic (endurance) base is critical to allow recovery from these session. They are most effective in the sport specific building period, after the initial aerobic base period.
- Do not carry your weight downhill! Either carry weight as water and dump it at the top, carry rocks to the top and leave them, or carry weight plates and use a gondola or other transport to get back down.
In summary, we feel that athlete appropriate and sport specific weighted training is a relevant tool for mountain athletes and some uphill specific runners. Additional care should be taken concerning effects on irritation to joints and tendons. Hopefully these guidelines help you determine if weighted training could be a useful component of your training program. We use it sparingly, even with our alpine athletes, and as part of a specific strategy. If that all sounds a little daunting, reach out to see how we can help you incorporate sport specific training into your plan!
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