As runners, we are constantly looking for novel ways to increase performance. Searching for workouts that will produce big results and take our running to new heights.
Often we fixate on finding tougher, more challenging workouts — more intense, higher resistance, longer duration, etc — to achieve bigger and better training effects.
Strength training is a great example. It’s challenging but produces many performance benefits.
Hill running is another example where we push through the pain from burning thigh muscles and searing lungs for those all important improvements in strength, power, and fitness.
But what if there was an easier way?… Well, that’s where research looking at the strength benefits of uphill and downhill running comes in.
Research Comparing Uphill and Downhill Running Intervals
In this article, we look at a new study published in Physiological Reports. Here, scientists investigated how uphill (+10% incline) and downhill (-10% incline) running intervals affected components of strength.
In particular, the scientists wanted to evaluate how running at 90% of maximum aerobic speed affected the rate of force development, strength endurance and squat jump performance.
So why did researchers examine the strength benefits of incline and decline running?
While several studies have examined the performance benefits (maximum velocity, running economy, etc) of hill interval training and downhill running, there has been limited attention on how this affects key components of strength:
- Peak force
- Rate of force development
- Strength endurance.
The key findings:
- Uphill running was more beneficial for strength endurance
- Downhill running significantly improved key power components: jumping ability, rate of force development, peak torque.
About The Hill Interval Research
First, the researchers paired the participants (recreational athletes with a running and cycling background) by BMI and VO2 max and then separated these into two groups.
They then used a series of tests to determine:
- Maximum aerobic speed (the velocity at VO2 max),
- Jumping performance (squat and countermovement jumps),
- Maximum voluntary contraction, rate of force development and absolute torque values
- Strength endurance (reps completed and total work)
- Muscle architecture
Following testing, they completed 16 hill running workouts over an 8-week period.
Each training session comprised 10 × 30second intervals (run at 90% of vVO2max), with 60seconds of rest between intervals. With one group completing the intervals on a gradient of +10% and the other on -10%.
Half way through the training block, the researchers retested the velocity at VO2 max and adjusted the training speeds. And at the end of the training block, they retested the subjects for the components of strength.
What did the researchers find?
Summary of the research:
- The downhill running group significantly improved jumping ability in the squat jump (9.9%) and showed a non significant improvement in the countermovement jump (6.6%).
- Uphill running didn’t benefit jumping ability.
- The downhill running group increased their rate of force development and significantly improved the absolute knee extension torque.
- Strength endurance increased in both groups (number of repetitions completed and work done), however it was only the uphill group that showed a significant improvement.
So what can we take from this research?
First, downhill running served as an excellent method for improveing jumping ability, the rate of force development and knee extension torque. These are all beneficial for power development, injury prevention, and help to explain how downhill running can contribute to improvements in maximum speed.
The researchers noted that the results were comparable to more complex strength and power training methods.
Second, the uphill running proved effective for improving strength endurance. However, the researchers noted that downhill running was also effective (to a lesser extent) and may help to maintain, or even increase, strength endurance.
What was really interesting here was the intensity of downhill running — the oxygen uptake (during the downhill running) was only around 50% of the uphill intervals.
This makes the downhill intervals “metabolically” far less stressful than the uphills. Although, it’s important to remember that downhill running culminates in increased inflammation because of the eccentric muscle contractions.
So why didn’t they use a faster downhill speed?… The researchers used this intensity to emphasise the Stretch-Shortening Cycle while reducing injury risk and muscle damage.
Clearly, this approach for the downhill running worked well.
Applying this to hill training
The first point to note is uphill and downhill running both produce distinct training adaptations.
- Uphill running emphasises strength endurance
- Downhill running emphasises power, rate of force development, and peak torque.
Therefore, to gain the most from hill running, it’s wise to integrate both uphill and downhill running.
At this stage, we cannot state whether this should involve separate “specific” blocks of uphill and downhill running; or whether we should alternate between uphill and downhill running workouts; or even combine uphill and downhill running within the same workout.
I’m guessing you probably include some hill running in your program or have in the past. But maybe not specific downhill running? If that’s the case then now might be a good time to give downhill running a try.
While I include downhill running, this is employed much less frequently. In part that is due to the impact associated with downhill running intervals.
The downhill intensity is very manageable
The downhill running intervals used during the research are simple to incorporate within a running program. Mainly because of the lower intensity.
The speed is also very manageable and feels quite comfortable (especially when you have gravity to assist you).
Another relevant factor is that the intensity used for these sessions shouldn’t interfere with, or negatively affect other training sessions.
It strikes a good balance between achieving the desired training effect, whilst minimising the risk of muscle damage.
My experience with these downhill running intervals
So after reading the research, it was time to try these out for myself. I did slightly modify this:
First, rather than running this as a standalone session, I added this on to the end of another session – in this case a threshold run.
So why combine it with another session?… This was maximise the training time. I often combine tempo/threshold running with hill intervals, so here I just substituted the uphills for downhills.
Second, I used slightly faster speeds than used during the research. Here I ran these at the velocity of VO2max (or slightly quicker), rather than 90% of vVO2max. This was because I already include some downhill running within my training. If you don’t then start with 90% of vVO2max.
Third, I employed a longer recovery ratio – around 1:3 rather than 1:2. This was because the recovery was uphill, and i’d already completed my main session, so the focus wasn’t on aerobic fitness.
Fourth, the slope wasn’t quite 10%. This was down to the logistics of finding an appropriate hill on that training route. However, it’s wise to ease yourself into downhill running.
Fifth, I ran 6 rather than 10 downhills — this was just a test after all, and it was combined with a threshold run.
So how did I find the downhill intervals?…
The intensity was very manageable – even after pairing this with the threshold run – and it was very easy to hit the pace targets.
In terms of heart rate, I was only hitting a peak of 150bpm (~80% of heart rate reserve) during the downhills. So again, nothing unduly stressful there.
Importantly, this intensity didn’t result in any DOMS. That said, I already include some downhill running, which inoculates your legs against DOMS.
How to find 90% of your velocity at VO2 max?
First, what is the velocity at VO2max?… This simply refers to a speed, or pace, where oxygen uptake is at maximum.
For most runners, this is a pace that’s sustainable for around 6-9minutes of intense running. You can learn more about how to identify this on the following page: the velocity at VO2 max.
Once you’ve determined this, reduce the speed, or pace, by 10% to establish the equivalent speed the researchers used for downhill running. You can then use this as your pace target for downhill running intervals.
As mentioned earlier, the researchers used: 10 x 30seconds at -10% gradient and a 1:2 work to recovery ratio.
One major advantage here is the session time is quite brief — 10 x 30s + 9 x 60s recovery = 14mins. Which is why — if you have a good level of running experience — you might want to consider a similar approach to what I described above (combining these with another session).
Whatever approach you choose, downhill running is an excellent (and easier) way to ramp up your strength, power, running speed and to reduce injury risk. Importantly, we can achieve this without suffering excessive muscle damage or DOMS.
Hopefully, this article has provided some insights into the benefits of downhill running and how to integrate that within your training.
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Theofilidis G, Bogdanis GC, Stavropoulos-Kalinoglou A, Krase AA, Tsatalas T, Shum G, Sakkas GK, Koutedakis Y, Karatzaferi C. The effects of training with high-speed interval running on muscle performance are modulated by slope. Physiol Rep. 2021 Jan;9(1):e14656. doi: 10.14814/phy2.14656. PMID: 33400851; PMCID: PMC7785049.