How Can I Improve My Race Performance?

By Karen Hancock

Ian complained after a recent race that his 10k times had remained stubbornly static for a year or so. He had been focusing his training on marathons, with the emphasis on long, slow and marathon-paced runs. If he really wants to improve his race performance at shorter distances, he needs to do some of his training at a faster pace: he’ll need to start doing some interval training at his VO2 max pace. Sessions like 5x 1 mile at his current 5k pace with about 2-4 minutes recovery are ideal. To understand why, you’ll need to understand a bit of theory, so read on….

Races are basically contests to see how much oxygen your body can deliver to your exercising muscles, especially those in your legs. Increase the amount of oxygen, and you will run faster. One of the factorslimiting your racing speed is your maximal oxygen uptake: your VO2 max, so you need to know how to increase it. I am assuming you already have a good base of endurance, and have at least experimented with training at or above your lactate threshold. But first, we need to clarify some terms:

HEALTH WARNING: confusion over the different maxes can seriously affect your training efficacy. Written advice is not always clear which max it’s referring to, so it’s always worth checking, as they are not interchangeable.

Concept Definition Can it be improved through training?
VO2 max The maximum volume of oxygen delivered to your muscles per minute. Yes
vVO2 max The velocity (speed) at which you can run at your VO2max Yes
Max heart rate (HR) The maximum number of times per minute your heart can beat under maximum stress. No: age, sex and genes determine your max HR, though rate of decline with age can be slowed.
Heart Rate Reserve (HRR) Your max HR minus your resting HR. Advice to run at 70% of your HRR means you need to calculate 0.7*(Max HR-resting HR)+resting HR. Yes, through lowering your resting pulse rate

What is VO2 max?

VO2 max is the maximum volume of oxygen (O2) delivered to your muscles each minute. Runners with a high VO2 max have a broad-band plumbing system (to mix metaphors horribly) which allows them to deliver large amounts of oxygen-rich blood to their working muscles. It is usually expressed in millilitres of oxygen per kilogram of bodyweight per minute (ml/kg/min).

So what governs my VO2 max?

There are three factors:

  • Max HR: This is the one factor you can’t do much about, but with the right training you can improve the other 2 determinants;
  • Stroke volume: the amount of oxygenated blood which your heart can pump out with each contraction. As your heart gets stronger, it squeezes out more oxygenated blood into the arteries with each stroke, which helps to lower your resting heart rate and thus increase your heart rate reserve; and
  • Proportion of oxygen in your blood that your body can use. In more detail, it's the amount of oxygen in your arterial blood – on its way from the heart, enriched with fresh oxygen, to those hard-working parts of the body, minus the amount of oxygen left in your venous blood returning to the lungs and heart for more supplies of oxygen. One of the changes brought about by training is that your tissues can extract more oxygen from arterial blood, leaving your venous blood with a lower oxygen level than untrained people. So the differential between the 2 increases with training: your body becomes more efficient at mining the oxygen in your blood. This happens because training increases the flow of blood to working muscles and the number of capillaries providing blood to individual muscle cells.

Another factor that the literature often overlooks is bodyweight, which is odd. Since VO2 max is expressed in terms of millilitres of O2 per kilo of bodyweight per minute, if you reduce your fat stores, ceteris paribus, your VO2 max will increase. Fat has a poor blood supply, so is not a part of your oxygen-delivery system. If you have too much of it, it’s deadweight. Unfortunately for us women, we have a higher percentage body fat than men, so our VO2 max will tend to be lower on average. The impact of low body-fat is obvious when you notice that the thinner runners are generally nearer the front of a race.

How can I measure mine?

There are two main ways:

  • in a lab using a device that measures the volume and composition of gas exhaled while you run as hard as you can on a treadmill or pedal to exhaustion on an exercise bike; or
  • more easily, but less reliably, using a either a Balke test, a Cooper testor a bleep test. These tests are conducted on a track or in the case of the bleep test in a sports-hall. Readings can be affected by weather conditions, however.

Sounds complicated. Can I still improve my VO2 max without measuring it?

Yes. I had my VO2 max measured in a sports science lab in the early 90s when I was an academic at the University of Glasgow – and very fit - but I cannot say I made much practical use of it in my training. What’s more important for helping to devise effective training is knowing your VO2 max pace or vVO2max. If you do happen to know your VO2 max, you can calculate both your VO2 max training pace and your race pace using a very useful tool on Owen Barder’s Running for Fitness website. There are 2 simpler ways of estimating your VO2 max pace, however:

  • using a HRM, you need to be running at 95-98% of your HRR, which is 96-99% of your max HR; or
  • about your 3,000m to 5k race pace.

In terms of how it feels, I would describe the right effort as "hardly comfortable". Where your long runs might be at a comfortable, conversational pace; your lactate threshold runs will be at a comfortably hard pace, where uttering short phrases might be possible. VO2 max running is one notch up from that. You can hardly manage a single word, and as the session goes on, you get too confused anyway to think about what is being said to you.

How can I improve mine?

You need to do some of your training at your VO2 max pace. Make no mistake, this is hard work. But as well as improving your oxygen-delivery capacity, faster running has the added bonus of helping to improve your running economy, the subject of my next article. In order to reach the required speed, you’ll need to get up on your toes more, pump your arms like a sprinter, and increase your stride-length.

What sort of training sessions will improve my VO2 max?

Most athletes do their VO2 max training in the form of interval sessions (a series of hard efforts interspersed with recovery intervals). It’s easy to design your own sessions using the following principles:

  • Pace of efforts: you need to run your efforts at your VO2 max pace;
  • Duration of efforts: if you’re focusing on the longer distances (10k-marathon), it makes sense to make your efforts as long as possible – 600m – 1 mile say – in order to spend as much time as possible in the right zone. You can make each effort the same length – e.g. 5 x 1,000m at 4:00 each (for a 20-minute 5k runner), with 2:00 to 3:30 recovery jogging. Alternatively, you can relieve the mental tedium (and get more out of yourself) by doing ladder or pyramid sessions, such as 600m, 800, 1000m, 1200m, 1000m, 800m, 600, all at the same pace per kilometre. That'll give you 6k in total and may even seem mentally easier than 5 x 1,000m.
  • Duration of recovery intervals: since you’ll be running these efforts at a faster pace than your lactate threshold-raising training (see How can I run faster?), you will need longer recoveries after each effort in order to keep them all at the required pace. Each recovery interval should be long enough to get your HR down to below 65% of your HRR or about 75% of your max HR. That will probably take between 50 and 90% of the time you ran your effort in. You’ll find it will take longer to get your HR down to the required level as the session goes on, so if you’re planning to make the intervals the same duration, you need to work out by trial and error how long they need to be to ensure you still get down to that recovery HR by the last effort.

Should I sign up for the club’s track sessions then?

Training on a track has the advantage of giving you an exact measure of distance, company to train with, and possibly a coach shouting splits so you don't need to move your head to look at your watch. Many runners also find that they don’t have the mental discipline to get through a tough VO2 max session. There are several disadvantages. First you have to get there, which can add hours to your investment of time, and is a bit tough if you travel away from home a lot. Second, too much running round tracks in the same direction can lead to particular types of injury. I'm convinced all my left leg hamstring problems are at least partly due to years of twice a week track sessions. And if the track is an especially hard one, it makes your legs sore. Third, it's mentally taxing: I strongly believe that variety is critical to maintaining the joy in your running and getting the most out of yourself. Fourth, the track sessions on offer may not be designed to suit your goals (so check with the coaches first). And finally, the club's track sessions can get very crowded, so the coaching input you receive can often be highly diluted, despite our coaches' best endeavours.

Here are some alternatives:

  • Cycle or footpath intervals: If you can find a traffic and interruption-free segment of about a mile (1.6km), you can subdivide it into half (800m) and quarter mile (400m) segments using a bicycle odometer (or a speed and distance monitor for gadget enthusiasts). You can make this your local training ground and invite nearby running pals to train with you, thus making better use of your limited time.
  • Running on grass: measure roughly the appropriate distances on a golf course or parkland. Running on grass helps work the calf muscles and ankle joints, so increasing flexibility and leg-strength at the same time. So long as your landmarks don't move, you will notice improvements over the weeks. Jog around your intended loop beforehand to check for hazards. If the grass is smooth and not too hard (eg, a cricket pitch) you can even enjoy running a session barefoot, which can help to improve your running form.
  • Try fartlek sessions – a more loosely-structured workout, beloved of the hippies amongst us, which alternate hard surges with recovery jogs within a longer run of say 8-10 miles. If you can do these on trails and parkland, so much the better. These are best done in small groups of similar-ability runners, with one being the leader for that week, who nominates the next tree or park bench to run hard to. These are particularly recommended for cross-country runners.
  • Hill training: the beauty of hill training is that you are working against a resistance, so you will do more work per mile run than you would on the flat. So it's very efficient as a way of increasing your VO2 max. And there's the added bonus that you’ll increase the strength of your leg muscles. You will also train yourself to run with better form and therefore efficiency (if you follow your hill coaches' advice). Find a reasonably steep hill at least 200m long and work up to 3 sets of 5 efforts, with a jog back down recovery between each effort and about 3-5 minutes easy jogging between sets.

How often should I do VO2 max training?

Much depends on your objectives and your running history. If you’ve never done any form of speedwork before, introduce these sessions gradually, aiming for 2 or 3 repetitions to start with, and building up to run about 5-8k at the hardly comfortable pace.

If you are targeting improving your 5k time, then you need to spend more time improving your VO2 max – assuming you have already built up your endurance base – than you would if your goal is to run faster at the marathon. Here’s a summary guide to the frequency of VO2 max versus lactate threshold (LT) training which I would recommend when targeting races of different distances for the non-elite, non-beginner athlete.

Target race distance Frequency of LT sessions Frequency of VO2 max sessions No. of speed sessions per week
5k 1 per fortnight 1-2 per fortnight 1-2
10k-1/2 marathon 1 per fortnight 1 per fortnight 1-2
Marathon 2 per 3 weeks 1 per 3 weeks 1

How do I know it’s working?

The purpose of training is to improve your race performances. Don't expect immediate improvements, but after you've been incorporating VO2 max training into your schedule for about 6-8 weeks, go out and race a 5 or 10k and see what happens. You’ll be able to tell whether yours has increased when you’re setting personal bests, and as your resting heart rate comes down.

Let me know how you get on.

Karen Hancock
Level 2 Endurance Coach

September 2004