run training joint angles ultrarunning

Top 3 Changes That Will Revolutionize Your Run Training


By Jason Koop,
Head Coach of CTS Ultrarunning,
Author of “Training Essentials for Ultrarunning“,
Host of “Koopcast” podcast

Run training has historically been driven by training paradigms rooted in its past. Alternating hard and easy days, long runs on Sundays, 7-day training cycles and even shoe rotation. These all made their way into runners’ vernacular by one runner passing the practice down to the next. Some of these practices have stood the test of time and formed some of the foundations of ultramarathon training. Other bits, quite frankly, make little sense, particularly for trail runners. If you train for trails, the concepts below will make a difference in your training–and ultimately results.

#1: Track your run training volume by time, not miles

Road and track running traditionally track training volume by miles. Look in any marathon training book and weekly volume, as well as intervals, are all denoted by miles. Shorter intervals may be written as yards or meters. This works well when pace distribution is narrow, which is the case when running on roads or a track. Take even the most elite runner, and their pace distribution from fastest to slowest might be 100% (say from 4:00 min/mile pace on intervals to 8:00 min/mile pace for an easy run).

This might seem like a wide range but pales in comparison to a trail ultrarunner. You might hold 7:00 min/mile running on the flats and 30:00-40:00 min/mile while hiking uphill. The figures below are speed distribution graphs from two different runners with the same weekly volume. The first runner predominately trains on roads while the second runner trains on trails. It’s easy to see that the road runner’s pace is concentrated in one speed range while the trail runner’s speed range has greater variance.

Adaptation is driven by the amount of time you are exposed to a particular intensity, not by the mileage you have run. For example, we know that for adaptations related to VO2 max, you need to run for >10 minutes at >90% of your VO2 max in order to elicit any reasonable adaption. You can do this as one continuous effort, through intervals (which we would call RunningIntervals), or even during a race (like a 5k). Adaptations across the intensity spectrum are similar. It takes a certain amount of time at a particular intensity to produce an adaption. Whether you cover half a mile, 2 miles or 5 kilometers at that intensity is inconsequential.

How this concept benefits you

Shifting your view of volume to focus on time instead of miles enables you to track your training load better. When you move to different terrain and run slower or faster, you have a consistent basis to evaluate whether your training load is increasing, decreasing or remaining the same. If you are doing intervals, you can do them uphill or on the flats and have physiologically comparable workouts, so long as you design the workout construction similarly.

#2- Determine intensity by rate of perceived exertion, not heart rate

Early in my career, I worked with all types of endurance athletes: cyclists, triathletes, runners, cross country skiers, you name it. The widespread adoption of cycling power meters transformed training for cyclists and triathletes. We could could directly measure the work performed on the bike in Watts. This gave coaches and athletes a precise method of prescribing intensity.

Previous to this transition, heart rate was the widely accepted method of prescribing intensity. The process to identify training ranges for an athlete was simple. We would have an athlete do some type of field test to estimate lactate threshold heart rate. We would then design training ranges around that estimated lactate threshold heart rate.

When athletes started adopting power meters for training, we used the same process. We identified power at lactate threshold and then design training ranges around this point. However, when the community of cyclists and triathletes shifted their intensity prescription to power and away from heart rate, some of the flaws inherent with heart rate prescription became evident. We saw that as intervals progressed, heart rate drifted even if power remained constant. The same effect would be seen with longer endurance rides.

The phenomenon became so prevalent, renown coach Joe Friel coined the term ‘decoupling’ to mathematically describe how HR and power would drift apart. A few years after this transition from heart rate to power, we all looked like idiots as we realized that many of the heart rate prescriptions were missing their physiological marks.

How this concept benefits you

While trail runners still do not have a power meter equivalent, prescribing trail run training by heart rate should not be the fallback, as it has the same inherent flaws observed with cyclists and triathletes. In addition to this, conditions that affect heart rate, such as heat and altitude, are naturally prevalent in trail running, particularly during races. Your race might start out in the cool morning, transition to a hot afternoon, and back into a cool evening, which complicates heart rate ranges due to the heat.

The same goes for altitude. When you go up or down by just a few thousand feet, your heart rate response to exercise is altered. Add to the mix other ultrarunning elements like dehydration, simulants like caffeine, and even drowsiness in longer races, and it’s near impossible to come up with a heart rate based race plan.

You want to race with the same method you use to determine intensity you used in training. Rating or perceived exertion (RPE) is your only metric that you have that effectively alchemizes all of the environmental and physiological phenomenon that you will encounter on the racecourse. So, use RPE to determine your day-to-day training intensity levels.

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#3- Look at vertical gain by feet of change per mile, not the total amount

Trail runners love their vertical. They wear it as a badge of honor with each and every run. Apps like Garmin Connect and Strava will let you track and compare your vertical gain just as easily as miles. Like mileage, it’s easy to see why runners used this as a comparative measuring stick. It’s simple to track and it’s intuitive that more vertical leads to a harder run. Plus, selfies are way better above tree line, which is only achieved after copious amounts of vertical gain.

The problem is, there is no dose response related to amount of vertical gain or loss. Two thousand, 4000 or 8000 feet of vertical are all similarly meaningless to your body. The adaptations you get from vertical gain and loss have very little with how much elevation gain you tally up.

How this concept benefits you

When you seek out vertical gain and loss in training, you are primarily looking for two adaptations. First, look at descending to increase your ability to cope with eccentric loading associated with downhill running. Ironically, this adaptation comes relatively easily with very low doses through a physiological phenomenon referred to as the repeated bout effect, which simply implies that one or a few doses of eccentric exercise are enough to produce a protective effect against subsequent bouts. Whether that dose is 2000, 4000, 8000 or even more feet of descending is largely inconsequential. This is because the dose required is relatively low (one bout leads to protective effects).

Second, you look at vertical ascent to prepare your body biomechanically for the differences between uphill, downhill and level running (see figure below).

joint angles ultrarunning

Figure 1- The hip, knee, and foot are all in different positions when walking or running on level ground, running uphill, and running downhill. Adapted from Yokozawa 2006; Guo et al. 2006; and Hicheur et al. 2006. Illustration by Abby Hall

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As with descending, the total amount of vertical gain you achieve in training is inconsequential. There is no biomechanical load associated with doing 2000, 4000, 8000 feet of gain. What your body cares about is how you move and how you use your hips, knees and ankles at different angles. Therefore, what’s important is the vertical gain- and loss-per-mile in training compared to your event.

If you’re training for a 50-mile race with 8000 feet of vertical gain and loss (16,000 feet of change), the course has an average elevation change of 320 feet-per-mile. Target this rate of change in training to ensure you can run effectively over all the different grades.


Three of the simplest metrics that many ultramarathon runners rely on for planning and tracking training are flawed. Outdated methods include measuring volume by mileage, intensity by heart rate, and vertical by total elevation gain/loss. Individually, they each reduce the quality of training. In some cases, the combination of two or three of them can completely derail training. For most athletes I help through this process, shifting to training by hours, gauging intensity by perceived exertion, and matching your elevation change in training to the feet-per-mile in your goal event makes training more efficient and reduces wasted effort and junk miles.


Comments 8

  1. Totally concur with using RPE as your training guide for workouts. As I coach runners 40+, shifting from zone training to RPE has been a very positive step to gauge daily progress. Good article. Thanks!

  2. Very informative,but also write for the veteran runners. I am 54 now diabetic and HT since last 20 years. Now Ican run 11k at the stretch and want to run a marathon. I am begin. Please guide for Protein intake also.

  3. these basics have never left the minds and methodologies of many. it has not been hard to integrate–as opposed to replace–the newer and useful tech to get more specific or validate. sometimes you have to fall into the hole to climb out, other times you can jump across the hole and kep moving forward.

  4. Such a great informative post. I am glad to be here and read this. Now I need to try to put it into practice 😉

  5. Very informative as always! My question relates to the idea of running “power” pods that have been engineered to help give a new metric to running. Is this something you believe would be a beneficial metric for ultra trail running, similar to how power has advanced the way both cyclists and triathletes have adapted their training and race strategies?

    Thanks for the article, Jason! As an analytically-minded athlete, I appreciate your deep dives into training and adaptation!

  6. I’ve read and heard your opinion on heart rate several times now and it still doesn’t make sense to me. Surely the factors that make your heart rate drift up (such as heat or altitude or a steep climb) also increase your RPE rise for a given pace? So if you decrease your to keep your RPE where you want it your HR tracks down also. What am I missing?

    1. Your breathing will normally feel more challenged on the first interval until it settles into the rhythm. Your heart rate will increase as you get tired.

      Try to run your intervals at a consistent steady pace and notice your breathing. Afterwards, look at your training data. Notice how your heart rate has changed during the intervals. Then you will understand it.

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