The key to improving your half-marathon times is in your 10K running
Autumn is a popular time to run a marathon, but its offspring – the half-marathon – is also a fairly common event at this time of year. The shorter race is sometimes looked down on by incorrigible marathoners, but such aspersions ignore some basic facts. First of all, half-marathon training can lead to much-improved marathon and 10-K performances. In addition, half-marathons are much easier to recover from than the marathon. The half- marathon is also a tremendous race to run as a workout; it can have a very useful effect on your LTRV (lactate-threshold running velocity). And of course, the half-marathon is a great race for someone who wants to run something long but isn’t quite ready for the relentless pounding of a full 26.2-mile competition.
On the other hand, preparing for a half-marathon is like pre- marathon work in two key aspects, which we’ll mention in a moment. And of course in a very fundamental way half-marathon groundwork is much the same as getting ready to compete at any distance: In order to do well, you must first completely understand the specific demands of the race you’re going to enter – and then shape your training so as to best prepare yourself to meet those demands. In that regard, it matters not whether your distance will be 800 – or 21,100 metres!
Getting down to cases
So let’s look at the specific requirements of the half-marathon. Obviously, if you want to complete the race successfully, you do have be able to cover 13 miles in one crack. That’s no big deal: building up to a training run of 11 to 12 miles will reassure you of your ability to do that. However, the really important point about the half-marathon is that its intensity – if you prepare yourself properly – will be just 2 to 3 per cent lower than your lactate-threshold intensity, or LTRV. LTRV, you’ll remember, is the running speed above which large amounts of lactate begin to pile up in your blood. It’s also the best predictor of your performance prowess – at events ranging from 800 metres up to the marathon.
Now, that observation – that half-marathon intensity is 2 to 3 per cent below LTRV – tells you two very important things. First, you must train yourself so that you can function just a tuck under LTRV for a long time, or more specifically, for the full 13 miles of the race. Second, the higher your LTRV, the faster will be your half-marathon time. If you move LTRV up by 1 per cent, your half-marathon clocking will improve by 1 per cent. Raise your LTRV by 5 per cent, and you cut your half-marathon time by the same amount. You’ve got to train to maximise LTRV!
Of course, that links the half-marathon with its mother, the full marathon. In the latter, there’s also a tight bond between LTRV and race pace, which is about 5 per cent below the lactate figure. And, as in the half-marathon, marathon times improve as LTRV ascends. Hike LTRV by just 7 metres per minute, and your marathon pacing will climb by the same amount, shaving more than five minutes from your finishing time if you’re about a three-hour finisher.
However, there’s another critical link that you’re probably not aware of. Although people tend to connect the half-marathon with the marathon, it’s of course much closer, distance-wise, to the 10K. If you can run a 10K, you just need to tack on 11 more kilometres to finish a half-marathon. In contrast, if you can run a half-marathon, you need to figure out a way to handle 21 more Ks if you want to complete a marathon. To put it another way, a half-marathon is just about one-third of the way – not half of the way – in total distance between a 10K and a full marathon.
In spite of that, your pace for the half-marathon, if you’ve trained properly, will nestle in about half-way between 10-K and marathon velocities. Run the 10K at 4:20 per mile, and your half-marathon tempo should fall no lower than 4:34 per mile. Meanwhile, your marathon time will settle at just about 4:48.
Run the 10K in 6:24 per mile, and your half-marathon striding will scoot you through each mile in 6:45. If you try the marathon, you’ll run at about 7:04 or 7:05 tempo, at least for most of the race. Again, half-marathon speed is almost exactly between 10-K and marathon pacing.
If you usually ease through your 10Ks at about 10:02 per mile, your half-marathon running will settle in at around 10:34 per mile. And, once more, that will be half-way to your marathon pace of roughly 11:06.
Interesting, but so what? Well, the ‘half-way’ position of half- marathon velocity means that the intensity demands of the half- marathon are as close to the demands of the 10K as they are to the marathon. That’s a very key point (remember: to train appropriately for a race, you must first recognise the specific demands which that race will place on you).
Since half-marathon and 10-K intensity are close together, preparing for and running a series of 10-K races will really help your half-marathon performances. For one thing, the neuromuscular- coordination requirements are similar, so there will be a good ‘carry- over’ from the 10K to the half (as you get more efficient at 10-K pace, your economy while running the half should also improve). In addition, 10-K work will make half-marathon pace feel less stressful, since the latter race is slightly slower.
The road ahead
So, you’ve got three primary tasks ahead of you as you prepare to run a great half-marathon: (1) you should train as though you were getting ready to run a terrific 10K, (2) you should maximally boost LTRV, and (3) you should learn to function at just-under LTRV (eg, at half-marathon tempo) for longer and longer periods of time (in fact, 13.1 miles would be nice).
How do you do that? Pretty easily. We’ve already covered optimal 10-K training fairly extensively in past issues of PP (see issue 68, April1996 for the latest update). If you’re a faithful subscriber, you already know that 5-K races, five- minute intervals at 5-K pace, 10-minute intervals at 10-K pace, and 10-K fartlek runs (during which you alternate two to three minutes at 10-K pace with one-minute jogs) represent the keys to 10-K success.
Boosting LTRV was also covered in a very recent PP (issue 73, September, 1996). You’ll recall that heightening LTRV involved (1) sparking along for 10 minutes at 10-K pace, with three- to five-minute recoveries (yes, the same workout you need for 10-K success), (2) hitting 10-K speed for six-minute intervals, with just one to two minutes of recovery, (3) sizzling through three-minute intervals at two-mile race pace, with two-minute recoveries, and (4) cajoling your legs into 25-minute continuous runs at a speed which is 10 to 12 seconds per mile slower than your current 10-K tempo.
But there’s one, absolutely critical additional workout – the one which satisfies the third requirement of half-marathon running, which is to learn to operate at your best-possible half-marathon speed for longer and longer amounts of time. That training session is called the PHMP workout, with PHMP standing not for a new sports- nutrition supplement but for ‘planned half-marathon pace’. It’s a very straightforward workout: you just warm up and then run at your planned half-marathon pace (PHMP) over a well-defined distance.
But how do you know what your PHMP is? It couldn’t be simpler. If you’ve trained correctly for the 10K, then you’ve been consistently running some good 10Ks. So, take your recent 10-K PB and multiply it by 2.222 to get your goal half-marathon clocking. Example: Nellie is feeling fit, has been running her 10Ks in 42 minutes flat, and would like to know her PHMP. 42 x 2.222 = 93.324 minutes, or about 93 minutes and 20 seconds (93:20). Dividing 93.324 by 13.1 miles, Nellie finds that her PHMP is about 7:07 per mile.
That’s it! All you need to know to be successful in the half-marathon. Now, you must simply put the ingredients together into a coherent training programme, and you’ll be all set to run a great race. Yes, we have a schedule for you, but note that we haven’t wasted space by putting down ‘Easy run of 5 miles’ under the Tuesday column and ‘Easy run of 4 miles’ in the Thursday slot. Instead, we’ll just give you the key workouts; the non-intense efforts are up to you. Basically, what you can do is prepare for some 10Ks, run 10-K competitions for a month or so, and then slip into a six-week training block which will lead you to a PB half-marathon. The key workouts in that block will look like this (you can position the workouts within the week according to your own preferences; for example, during week 1 you might do the LTRV run on Tuesday, the 10-minute intervals on Thursday, and the PHMP workout on Saturday or Sunday. The actual day of the week assigned to each workout doesn’t really matter, as long as you are recovering adequately between sessions):
The half-marathon schedule
Toughie No. 1: Three 10-minute intervals at 10-K pace, with 5- minute recoveries
Toughie No. 2: Three miles at PHMP
Toughie No. 3: A 5-K race or time trial
Toughie No. 1: Four 6-minute intervals at 10-K pace, with 1- to 2-minute recoveries
Toughie No. 2: Four miles at PHMP
Toughie No. 1: 3.5 continuous miles at LTRV (10 to 12 seconds per mile slower than your current 10-K PB)
Toughie No. 2: Repeat 800s at a pace which is 6 seconds per 800 faster than current 5-K pace
Toughie No. 3: Six miles at PHMP
Toughie No. 1: 10-K fartlek session (alternate 2- to 3-minute bursts at 10-K speed with one minute or so of easy jogging over a 10-K distance)
Toughie No. 2: Seven miles at PHMP
Toughie No. 1: Moderate hill session (on a tough, steep hill, do six or more repeats, but not enough repetitions to induce soreness)
Toughie No. 2: Three 10-minute intervals at 10-K pace, with 5-minute recoveries
Toughie No. 3: 5-K race or time trial
Toughie No. 1: Nine miles at PHMP (early in the week)
Toughie No. 2: 5-minute intervals at 5-K pace, with 3- to 5-minute recoveries. Leave the workout feeling fresh and charged-up, not mentally and physically drained.
Taper properly during the seventh week by trimming mileage by 65 to 70 per cent. Focus on short, fast, but non-soreness-inducing sessions (repeat 400s at 10-K pace). To run a great half-marathon on Sunday at the end of this taper week, complete six 10-K paced 400s on Monday, do a three-mile PHMP effort on Wednesday, and run three 400s on Friday. Everything else should be small and easy! If your half-marathon is on Saturday, back everything up a day (the 400s on Sunday, PHMP on Tuesday, etc.).
People often ask what the optimal weekly mileage level is for half-marathon training, but it’s important to remember that there’s no such thing. You’ll run your best half-marathon when you’ve reached your highest fitness level, not when you’ve racked up the most miles or attained a mystical mileage level mentioned in a running book or magazine article. Highest fitness means maximising VO2max and LTRV, developing the lowest-possible running economy, and stimulating your body to handle flawlessly the specific demands of half-marathon racing. The schedule outlined above is designed to do just that.
The same considerations apply when we think about what your longest weekly training run should be. Always remember that you run your best when you’re fittest, not necessarily when you have managed to build up to a15- or 20-miler. Probably the longest run you really need for half-marathon success is just 11 or 12 miles.