Effectively, you are teaching your body to run faster by running fast. So what does the runner who wants to get their PB down through speed work have to do?
Have a decent base
If you want to put in some decent speed work, it’s important that you start from a good base. That means you need to have been running for a while before you launch yourself at sprints, ideally around 3 months or so. With a solid base of running, which constitutes being able to run for at least 30 minutes without stopping, you can start to really build on other areas of your fitness. Sprints and interval training are not something you should leap into without building up to it, or you will sustain an injury.
Along the same sort of theme, it’s vital that you warm up properly before you start your intervals. The explosive movement of a sprint can very easily pull a cold hamstring or calf muscle, if they haven’t been warmed up first. Remember that the finely honed machine that is your body is going to be working extra hard, so you need to be ready.
Set your distance
You are looking to establish your intervals relative to the distance you’re running, but the length of the interval and the length of the recovery period need to be right to get the most out of this kind of work. For longer distance runners (half marathon and beyond) there is little point in having an interval of longer than 2 miles (3.2km). You may as well make it a tempo run. But four/five or six intervals of one mile (1.6km) at race pace, now that is worth doing, with adequate recovery in between.
If you’re training for a 5k or a 10k, you could aim for 800m (875 yard) intervals. Within that interval you could run the first 400m slower than the second and then the switch it up and run the first 400m (437 yards) faster than the second. Five of six of these intervals should give you a great workout.
Interval training will push your aerobic and anaerobic fitness. You’re aiming to propel your body to the lactate threshold during the speed interval, before encouraging your body to burn off that lactic acid during your recovery period. It hurts, but it’s good for you and will help build up your speed and endurance.
Pick the right surface
A bumpy trail might not be the ideal location for any kind of speed. You’re going to be shifting through the gears in a way you don’t normally do on your long runs, so a flat, smooth surface would be ideal. If you can get access to a running track then perfect. If not, try to pick groomed trails, where the surface is clear and hazard free.
Try to make each interval the same in terms of effort and work rate
This is really important in terms of making interval training effective. You don’t want to ruin yourself and indeed the whole session by killing yourself in the first sprint and then having nothing left for the others. The objective is to put in an equal effort on all of your intervals, so in an ideal world, your last interval should be as good as your first.
Focus on form
The key to good speed work is making your running form as smooth as possible. You’re teaching your body to run faster by running fast. This is a change from the more plodding endurance runs, so you must concentrate on technique. Think about your running, your stride pattern and your breathing. Accelerate into your interval and then maintain your speed, even when it hurts.
Speed work is tough and as a result you are probably best advised to restrict it to one structured session a week, but do make sure you commit to doing it once a week.In terms of mileage you’re looking for your interval training to constitute around 8-10 per cent of your weekly mileage output. And make sure you give yourself a rest day after a speed work day. Your body will definitely need it.
A good cool down after an interval session is as important as a good warm up. There is a much greater risk of injury when you’re running faster and pushing your body. Greater flexibility is always a fantastic way of fending off potential injuries, so do lots of stretching after your session. It will help disperse any lingering lactic acid and kick-start the recovery process.
Enjoy the difference
Training this way is hard work but it’s also great fun. You can be slightly less structured about your speed intervals by using the fartlek method if you prefer, which involves unstructured intervals of irregular duration. But the point is you are running faster and doing something different which is in sharp contrast to the longer endurance training you may have been used to. Embrace the difference. You may even come to love it and you will definitely enjoy the improvement in your races.
DIRT. This acronym is very useful to remember all the key aspects of speed training.
D – distance of interval
I – interval recovery period
R – number of repetitions
T – time or speed