Pacing
By John Steitz, MCP Coach
Starting with Sunday’s races, the next two months serve as the heart of your marathon training – when our Saturday “Long Runs” really are *long* runs – building up your strength and endurance for your target race in the Fall – either the Marine Corps Marathon, or the Baltimore Half Marathon.
One of the questions that comes up most often in training, and during races, is that of pacing. What race pace should I set for myself, to ensure optimum performance, while still reserving enough energy to complete the race, and to avoid injury? What pace should I set for myself during training, to ensure that I am sufficiently prepared for the race, yet avoiding injury that would knock me out of the race, or the rest of my training?
Unfortunately, there are about as many different answers to these questions as there are running coaches. And I suspect that there are different answers based on each person’s natural ability, running experience, training base, gait, injury history, performance goals, hydration, nutrition, and a host of other factors.
What I want to do in this article is to give you some information for your to interpret all the recommendations and pieces of training advice you will hear throughout your experience training for distance races, or in running of any kind.
Probably the best measure of your own level of effort during any run (or any other exercise) is your heart rate. The latest research and study has tended to look at effort expended (as measured by heart rate) instead of pace or distance run, as the true measure of training effectiveness. E.g., http://www.runningtimes.com/rt/articles/?id=7479&c=2
Measuring your heart rate while running has gotten a lot easier with recent technology than it used to be. Now, I’m not suggesting you run out a buy a heart-rate monitor for your training – you do *not* need on of these to complete marathon or half-marathon training.
But a heart rate monitor is a neat toy, and it will tell you a lot about your own physiology. Measuring your heart rate each time you run, can tell you how your body reacts to various stressors – heat, hydration (or lack thereof), glycogen levels (or lack thereof), distance, etc. You can run the same route two days in a row, in the same elapsed time, but your heart rate may be different on each day, as you may have to work harder, or not as hard, to achieve the same pace on the two runs, based on what your body is undergoing at that moment in time.
And if you train based on a given level of exertion, you train at that level – whether a 7 minute-per-mile pace creates that exertion on your body, or a 15 minute-per-mile pace.
In running advice, heart rate is usually expressed as a percentage of one’s maximum heart rate – the level of exertion one should not exceed under any circumstance. This maximum is affected by age, and was traditionally expressed as (220 – [person’s age]) = maximum beats per minute. For example, if I’m 42 years old, my maximum heart rate is 220 – 42 = 178 beats per minute. No matter how hard I exert myself, the fastest I will ever run at any given point his year is the pace where my heart-rate is up around 178 beats per minute – and even then, not for very long at all. Maybe if I’m running away from a falling building, or something like that.
[Newer formulas for heart rate maximums tend to differentiate by gender: http://www.coolrunning.com/engine/2/2_1/1127.shtml Wait until your second season of training before you go to this level of scientific tinkering.]
Two other factors which are not indicated by heart rate, but from which they usually can be estimated, are your “VO2 max” and your “lactic threshold,” closely related, but technically different.
“VO2 max” is the point where your circulation and respiratory systems are maxed out - the point at which your body cannot provide all the oxygen your muscles require, not remove all the carbon dioxide you muscles generate. Your body can continue to function with an oxygen deficit to your muscles, and this is called “anaerobic” (without oxygen) exercise. Anaerobic running is pure sprinting – you run like the wind, but you are totally winded within a few hundred feet, at most. You cannot keep up anaerobic activity for any length of time.
By contrast, “aerobic” exercise (with oxygen) is where your muscles’ demand for oxygen does not exceed your body’s ability to deliver it to the muscles. The vast majority of your running is aerobic, as is ALL your distance running.
VO2 max is somewhere around 80-90% of your maximum heart rate, depending upon the individual.
Your “Lactic Threshold” is the limit of your body’s ability to remove the lactic acid generated by your muscles during exertion. It is found at a heart rate level lower than the VO2 max, and is not usually pegged to a specific heart-rate. You ran run longer above your lactic threshold (but still aerobically), than you can above your VO2 max, but the distance you can do so is still fairly short – a few miles at most. Exceeding your lactic threshold usually results in aching muscles, but you aren’t necessarily out of breath.
The good news is that lactic threshold can be raised through training and experience, one of the adaptations your body undergoes as it becomes more fit. Versus the much, much more difficult task of changing one’s VO2 Max, which is the stuff of labs, white coats and chemicals – not on your training plan this year!
I explained these concepts because they relate to a lot of advice one hears from coaches. With heart-rate monitors, that advice is usually expressed as “Run at 82-88% for x number of minutes.”
Or elsewhere, it is expressed as “Run at a 5K pace.” Or “Run at a Half
But how do you know what pace to run if you’ve never run one of these races?
Well, measuring your heart rate is a good way to guestimate. Sprints are anaerobic, and your heart rate is way up there above 85% max. 5K races are usually run at a pace above lactic threshold, but below VO2 max.
Most training programs for 10K races and longer aim for a
race pace *just* below lactic threshold, but practically, the first time racer
doesn’t achieve these for anything above a 10K.
10 Mile or Half Marathon pace is slightly slower than 10K pace, and 20
Mile or
The best way to estimate your marathon (or half marathon) time is to run a few shorter races, to gauge your race pace. The races this weekend, and others in the next three months, will give you that opportunity. There are some neat web sites that will estimate your marathon finish time, based on your prior 10K, half-marathon, or any other shorter-race times, e.g.:
http://www.runnersworld.co.uk/news/article.asp?UAN=1681
http://www.runnersweb.com/running/calculators_hong.html#Marathon%20Time%20Predictor
Your time for a longer race is *not* merely a multiplication of the shorter distance. Even among the best runners, their best marathon pace is slower than their best 10K pace. The shorter the distance, the faster the pace you can keep up for that entire distance.
When all is said and done, there are two basic schools of thought regarding your training pace during marathon training. Most programs lean toward one or the other in their advice on pacing.
The first school argues that your pace while training is the pace you will be able to maintain on race day, so you should train at your target race pace. The repetition and conditioning your body undergoes keeping that pace in training will strengthen your body for better performance on race day. Because you cannot (nor should not) race faster than your train, your training must be at a consistent pace from day one, a pace that pushes your physical and psychological development. In terms of heart-rate, your pace should be somewhere in excess of 70% of your maximum. Most of the literature I have found recommend this approach for more advanced runners – not for first-time marathoners.
The second school counsels that, especially for first-time marathon trainees, that increases in distance should not be accompanied by increases in pace. Long runs should be run at a much slower than race pace, to build up endurance, while minimizing the risk of injury. Shorter, mid-week runs may be run at faster speeds, to get the body used to running at speed. But the only time that speed and distance should be combined (if at all) is on marathon (or half marathon) race day. In terms of heart-rate, your effort on a training long run should be somewhere in the 60s, percentage wise, perhaps faster on race day. c.f., e.g.,: http://www.joehenderson.com/lsdbook/forum.html
I, myself, tend to follow the second school for the folks I coach. The goal of your first marathon should be to complete the race, injury-free, and to post a finish time slow enough that it’s very easy to beat the *second* time your run a marathon. <g>
I also preach the concept of the “Negative Split.” [A “split” is any time that a run is split into two or more portions. Each portion is timed separately, so that in the case of a track workout, the first loop around the track (the “first split”) is at one time, while the second loop around the track (the “second split”) is another, etc.]
A “Negative Split” means that if you divide your run and your race into two halves, the second half should be run faster than the first half.
I preach Negative Split for folks of any natural pace or ability, because the marathon is *not* a sprint, a 5K, or even a 10 Mile race. It is a race at the upper limits of one’s natural glycogen reserves, a distance and time spent running that can dehydrate the body like no shorter race will, and a psychological test of endurance. The half marathon is only slightly less challenging for those new to running, or to those whom I call “Super Penguins” at the back of my flock.
If you practice Negative Split in training, you will resist
the natural tendency to race out of the starting gate on race day and waste all
your energy in the first few miles. You
will keep your reserves on hand for the end of the race, when you will need
every ounce of ability and endurance you have mustered over the previous six
months of training. You will keep a
consistent pace your 10, 15, 20 miles, instead of joining the death march across
the
To *do* a negative split, you have to deliberately run the first half much slower in terms of perceived effort. The reason for this is to conserve effort, to conserve resources, for the second half of a long distance. But the most important part is to SLOW DOWN at the start of the long run. Really. To the point where it basely seems like you’re putting in any effort. Keep that up for the entire first half of the run. Then run “normally” on the second half, back to home base – if you can. <g>.
So as you race or train this weekend, and as you training the remaining 3+ months toward your target race, please watch your pace. On your long runs, set a pace that you can keep up the entire route – or better yet, set a slow pace to start, that you can increase in the second half. If you find yourself walking the entire last portion of the Saturday long run, YOUR STARTING PACE WAS WAY TOO FAST! Slow down at the start, and keep at least a consistent pace start to finish. Don’t run your long runs as fast as your 2 mile runs around your neighborhood.
If you train properly, you will challenge your body to go beyond its limits, and you will complete your target race. But, as you set you pace on training runs, and on race day, respect the distance. Train hard the next few months, and train smart!