‘Comfortably hard’ sounds a bit like a contradiction in terms, yet that’s the feeling you’re looking for when you start thinking about thresholds. It’s helpful for runners to know where their lactate threshold lies. That’s the point during exercise when lactate – a by-product of your body using glucose to produce energy – is on the cusp of building up in your blood at a rate faster than your body can clear it away. Going above this point is when your muscles start to feel a burn and you feel a need to slow down. Running at threshold pace is essentially the hardest you can go for a longer time – it’s slower than your 5k and as part of half marathon pace. You can think about it in terms of speed, but it might be more practical to focus on heart rate, Aerobic and anaerobic exercise, explained.
Why is it useful to know your threshold heart rate?
Your threshold pace is the speed that you can hold for about an hour of hard effort, and the threshold heart rate is your heart’s beats per minute at that effort. While your pace will vary if you’re away from the track or the treadmill on a run with a few ups and downs, your heart rate can be a clearer measure of how hard you’re going at any stage. A 2023 review of studies into using ‘heart rate variability-derived thresholds’ in endurance sports concluded that ‘HRVTs can be a promising alternative for prescribing exercise intensity’ but added that more research is needed, especially in female athletes.
How do you find out your threshold heart rate?
What is the average finish time for 1km running watch of the best hill training workouts for runners Threshold heart rate: What it is and how it can help your training can be even more accurate. They can calculate your threshold zones automatically, though there are also a few formulae for getting a ballpark figure on your max heart rate. The most basic is 220 – your age (eg. giving a 45-year-old a max heart rate of 175bpm) or you could try what’s snappily known as the Tanaka age-based max heart rate calculation, which is 208 – (age x 0.7), making our 45-year-old’s number come out this time at 176.5. You can also think of it as a 7 or 8 out of 10 on the rate of perceived exertion (RPE) scale.
By dividing heart rates into and as part of, with zone 5 being closest to max heart rate, you can get a good idea of the ideal heart rate for different paces. If zone 5 is roughly 90-100% of your MHR, and zone 1, your easiest chatty pace, is 50-60%, then your threshold heart rate will be in zone 4, between 80-90%. Carrying on the sums, if that hypothetical 45-year-old’s max heart rate is 176.5, we could take 85% of that as a number to aim for as their threshold heart rate, ie. 150bpm.
You can also test the accuracy of your numbers out on the run, for example by running at what feels like a hard pace (using the ‘talk test’, you should only be able to get two or three words out at a time) for 30 minutes and using the average heart rate in the last 20 minutes as your threshold rate. (Don’t count the first 10 because you’re likely to go faster at the beginning and then slow down. You’re trying to find the hardest pace you can sustain.)
Why is threshold running beneficial for runners?
heart rate monitor VO2 max as a number that indicates physical fitness. However, threshold is a figure that is much more moveable than VO2 max, which depends somewhat more on fundamental physiological characteristics such as lung capacity. Consistent training at above and below threshold rate will make your body better equipped to clear its lactate and also be able to handle higher concentrations of the stuff. Thus your threshold pace can go up, and threshold heart rate go down, as you improve through training. Essentially, when you spend enough time regularly around threshold, you should find you are able to go faster for longer.
How can I structure a workout around threshold heart rate?
You can find plenty of threshold workouts on the RW site micro goals for runners Runner's World Club. They include interval sessions, steady efforts and progression work. To do them according to threshold heart rate, simply concentrate on keeping your bpm number consistent rather than focusing solely on the pace you’re running.
Bear in mind you don’t want to do this kind of training in every session. Common advice is to keep four out of every five runs at a lower intensity. But by making threshold sessions a regular part of your week, you’ll reap the rewards.
Are there any mistakes to avoid with THR?
drills to improve your form and speed recovery days in your training diary, to have the best chance of avoiding injury. Otherwise, it’s important to remember that every individual is different, so while the formulae here are a useful starting point, the key numbers for you specifically could well be different, and even change on different days depending on other factors such as the temperature or your fuelling. The best thing you can do is keep spending time in the threshold zone so that your body becomes used to what it feels like. Over weeks and months you may well be going faster, but you’ll still recognise what happens to your heart when the run gets harder.
