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Interval Running Half Marathon.

    Interval running half marathon is a great training tool to have handy when training for a half marathon or a marathon, come to think of it.

    Interval training is a speed workout built around several short and fast runs with easy to slow recovery intervals between that you repeat several times.

    In this article, I will share some of the interval training I do and explain why it’s effective and some best practices to get the best results from your interval training so that it helps you run a faster half marathon pace.

    Why Is Interval Running- Half Marathon Beneficial?

    Want To Run A Faster Half Marathon?

    Of course, you do! So to do this, you have to train your body to build up your speed base; interval training helps build your speed while reducing risks of injury and reducing recovery time from your efforts.

    You Need To Build Your Stamina For A Half Marathon.

    You need to build endurance and stamina to run a half marathon, especially if this is your first endurance event.

    Doing intervals really helps build your VO2 max.

    Why should you care about your VO2Max, you might ask?


    VO2 max can be used as a guide to finding out how much oxygen your body is utilising when exercising at maximum effort. Basically, it can determine how much oxygen your heart can pump and how much of that is being used by your body… Basically, how efficient are you at using the said oxygen…

    Now I don’t want you to get all bent out of shape about this. Many people can have varying Vo2 maxes and still perform at a high level, add to this that watches like Garmins that give you VO2 max readings are not accurate; you can see that most amateur runners won’t know their actual VO2 Max. However, it highlights why intervals are a great tool to use when training for a half marathon.

    Interval Training Enables You To Run Harder More Safely.

    I like intervals because the short bursts of speed and the rests enable me to run faster; however, they reduce the risk of injury. I also find that my recovery from intervals is good, even though depending on the amount of and type of intervals I am doing, it can feel like a high-intensity workout.

    I feel intervals are really efficient way to train for a half marathon.

    Improves Running Form.

    One of the factors I noticed about my running after doing quite a lot of endurance running was that I had developed this minimalist running style that worked, but many call it the shuffle.

    Now doing something like intervals opens up your body to variation. I feel it helps with your overall running form; however, it does it naturally without forcing anything.

    By performing the intervals, your body adapts to that and, in turn, evolves your running form and, as already mentioned, your speed and improves your half marathon pace.

    So you get two for the price of one!

    Why Doing Intervals Can Improve Your Goal Half Marathon Pace.

    The first point I need to make is there are many ways to arrive at the same destination.

    However, personally, I see many runners these days doing all their half marathon runs at a slow or steady pace.

    I have done this myself, and to be totally candid, I did get faster; however, as I looked into running more as I have got older to see how I could get the very best from myself, I started to see a pattern emerging.

    There is a lot of marketing in running as there is in most things, and it’s not to say, as I mentioned earlier, those extremes do not provide results.

    Running all your half marathon runs at a steady, slow pace with a low heart rate will deliver results.

    However, for me, like so many things, the truth rather boringly is somewhere in the middle.

    I have found that doing at least 20% of my half marathon running with some speed has enabled me to have more variation in my running even when I am now at the ripe old age of 57!

    I like to think of it as having gears when I run. I am a massive advocate of the zones.

    What do I mean by zones?

    The chart below gives you some idea; I will say you will see variations in this theme of zones. Don’t get too hung up on that.

    ZonesType Of RunningPerceived Effort% Of Heart Rate
    Zone 1Recovery1-250%
    Zone 2Endurance2-460-70%
    In Between Zone
    Zone 3.
    In Between Zone
    Zone 4Threshold6-885-90%
    Zone 5Hard Effort/Sprint9-1090-100%

    The whole point is to have a map of gears you can work through in your running. It also builds awareness of what gear and running you are actually doing at any one time.

    The important reason is you don’t want to run your recovery and endurance runs too hard, and you want to make sure that your speed sessions have enough challenge so that your body adapts and your progress.

    You can see on the graph above I have areas between Zone 3 called in-between zone, this is an area that if you train in this area for long periods, you tend to be in this mid-paced zone that is too easy so it does not deliver much adaptation or progress however too hard for quick recovery.

    It has to be said when training for endurance events such as a half marathon or marathon, your training at times can fall into this area, activity such as steady-state runs and progressions, however broadly, you do not want the bulk of your training in these in-between zones.

    So, for example, I would do my intervals at mainly zone 5; however, if earlier in my training plan, I do sometimes be in zone 4. But if you don’t know your zones, the likely hood is that you won’t do the intervals with the correct intensity.

    So How Do You Get To Know Your Running Zones?

    Well, your coach, if you have one, should set this up; however, if you are training with a generic plan, the best thing to do is go out for a benchmark run.

    The benchmark run is 40 minutes in total; if that’s too much, do 30 minutes. I warm up for ten minutes, then for 30 minutes, run as hard as possible. Now in my case, my coach Liam then sets up my zones; however, you could put your average pace into a calculator and get a good estimate of your running zones.

    Below is a video outlining how to use the calculator and a link to the calculator itself.

    Zone Calculator

    How Long Should Intervals Be?

    This is a hard one; all I can say is that it depends on your present fitness and your training plan.

    So, for example, interval pace can be around your 5k pace, and faster if you are doing short intervals, say, for example, 2-minute intervals, or slower if you were running for longer, for example, for five minutes.

    recovery, at half the time you have run.

    How To Do Interval Training For A Half Marathon Training.

    Ok, so now let’s look at doing some intervals for your marathon training. You now know why intervals will help you be faster on race day and, when integrated with your long runs, will make your workouts more specific and effective.

    Fast Intervals.

    We have been talking about pretty much throughout this article; as mentioned, there are many variations of intervals for you to choose from depending on fitness factors and your goals for your goal half marathon pace.

    A simple example could be…

    5 mins Z1

    5 mins Z2

    6 x (1 mins Z5 / 2 mins Z1)

    5 mins Z1.

    So warm up with a Z1 and move into Z2 for 5 mins and then begin your intervals. When running Z5, remember it’s all out; however, try and keep control of your running and breathing the best you can.

    Then recover for 2 minutes; I like to initially walk till my heart rate drops back to Zone 2 levels, then I very lightly jog till the next interval.

    If your heart rate stays pretty high, walk the whole 2-minute recovery.

    A variation on this is to make a recovery shorter, say a minute or 90 seconds.

    Tempo Intervals.

    Now tempo running and running at tempo pace ain’t intervals… Yes, you got me there but heard me out.

    If you are training for a marathon doing tempo intervals at race pace with an interval of recovery is a great segway into adapting your body to maintain your desired race pace.

    An example could be…

    3 x (15-20minutes at tempo running pace, 3-5minutes easy jog recovery)

    This really gets you into that groove of running at goal half marathon pace .

    As I have said in the true sense, this is not true interval training; however, its worth mentioning if you are specifically looking at doing a half marathon distance

    Hill Repeats.

    Hill repeats are a tremendous source for building strength, stamina and inner grit. You do not need a massive hill to perform hill repeats.

    Here is an example of a hill repeat my coach Liam has set up for me …

    5 mins Z1

    5 mins Z2

    12 x (30s Z5 uphill / 90s Z1)

    5 mins Z1

    Last Bit Of Advice About Interval Training For A Successful Half Marathon Pace

    We have spoken about interval training for a half marathon shower. I do have to conclude with this bit of advice.

    If you are new to the half marathon distance, make sure that the weeks before you start to do faster workouts build up the foundations of endurance and stamina that you can then layer on top of with speed work.

    Doing long runs or building up to them in your plan is vital, as is tempo runs at race pace and just generally getting miles under your belt.