Monday, February 04, 2013

Making The Transition Part 5 - 5k / 10k Pace Intervals

So you've run hard for 8 weeks and then taken a week sitting on your backside. Or to phrase it another way letting the training seep into your body. I'll normally find that at this stage my body has recovered well over the last couple of weeks and with the strides done my legs are feeling pretty good with a bit of "zip" in them.

What's missing though is that although by this stage you've run quite a bit more than you have ever done before, and also quicker than you've ever done before you haven't ever really pushed yourself or your lungs to that breaking point that you frequently hit in races. You've done some sustained longer running but that's all been sub-maximal and you've finished feeling like you could go another round (or at least I hope you have...).

The next step is to start connecting the quick strides with some fast sustained running.

5k/10k Pace Intervals

What are they?

5k and 10k pace intervals are repetitions run at either your 5k or 10k pace or somewhere inbetween from between 400m to 2000m (faster than 5k for 400m reps and 10k pace for 2000m reps) for a total of 4000-12,000m. If you're not sure exactly what those paces are then you can interpolate between other race performances. 

You take recoveries of roughly half the time of the rep distance. These recoveries can vary from stationary recoveries to a relatively fast "float".

The Theory

5k and 10k pace intervals are the corner-stone of any succesful distance runners arsenal. Whether that's Seb Coe stating "the 5k pace sessions are golden" or Runners World advocating Yassoo 800s all plans include some work at 5k to 10k pace.

The physiological aspect of the training is that when you're running at your 5k pace you're running at very close to your VO2 max. There are complicated definitions for this but in payments terms your VO2 max is basically when you're breathing as hard as you possibly can. This occurs at roughly the speed you can maintain for 6-10 minutes but 5k pace is still relatively close and you can get a much greater volume of work in at 5k pace than you can at 3k pace. When you're running much faster than this then you can still only take in the same amount of oxygen but you need to generate more energy (which results in you generating higher lactate levels and causes the "burn" you'll experience in a middle distance race).

Running at your VO2 max (in the short term) will improve your bodies ability to take up oxygen. This means that for the same breath ox oxygen you're taking your body will use a greater proportion of the oxygen effectively.

The Practice

In theory you should run intervals at 3k pace for it to be your VO2 max. I don't like to run these at 3k pace for three reasons...

1. In the middle of a heavy training week I'd expect your notional 3k pace to feel more like your 1500 pace and similarly your 5k pace will feel more like your 3k pace. You therefore want to be training at closer to your 5k pace. The best way to describe this is to imagine you were running up a steep hill - would you still expect to run at 3k pace? No - you'd be running considerably slower for the same effort. The training you're doing is effectively making your body feel like it's going up that hill.

2. You can include a lot more volume in the sessions this way which is better for your running economy. Running economy is a slightly technical term but if you think of it in terms of piano practice it helps. It may be useful to do scales but at the end of the day the best thing to do is to practice the piece you're playing. By getting used to the pace you're planning to run you improve your ability to run at that pace through a whole number of minute tweaks.

3. VO2 max training has been shown to significantly decrease it's effectiveness after the initial 6 week "boost". Whilst some advocate it year around I prefer to back off and only hit the really intense stuff at 3k pace immediately before a big race.

Generally I find that using a progression from fast and brisk 400s at 3k pace up to intense 2ks at 10k pace is a great natural progression. There's also nothing to stop you mixing the session about and doing 400s to start with and finishing with 2ks and vice versa!

The pace you use will also be a function of your ability. If your 5k is pretty close to 10 minutes then your name is probably Bekele and Farah and this article will be of limited use to you. If on the other hand your 5k is over 20 minutes then you'll be wanting to train at closer to 3k pace. Similarly if your 5k is significantly under 20 minutes then 5k pace is your friend.

The recoveries should be half the length of the running time of the rep roughly. 

Opinions vary hugely regarding how you should spend your recovery. My personal favourite is to keep it relatively brisk and jog at my usual easy run pace. A favourite session when in sub 16 shape is 8 x 1000m off a 200m jog recovery in 75 seconds.

Generally I find it best to do these sessions on a track but equally find a measured stretch of road or even do the sessions by time.

The Schedule

So for 3 weeks we have the following schedule...

3 x 40-60 minute easy runs
20 easy, strides, 20 easy
15 warm-up, 5k/10k pace session, 15 warm-down
15 warm-up, 20 @ threshold, 15 warm-down

With the sessions being...

10 x 800 at 5k pace off 200 fast jog
8 x 1000 at 5 mile pace off 200 fast jog
8 x 1200 at 10k pace off 200 fast jog

After this block of 3 weeks you'll want to take an easy week again. This leaves our schedule looking like...

Weeks 1-4 - Get used to running 5/6 times a week
Weeks 5-8 - Incorporate threshold running and strides into your schedule.
Week 9 - Easy Week
Week 10-12 Hard Training (5k/10k Pace Work)
Week 13 - Easy Week

By this point you should be able to see some substantial improvements in your fitness at the end of the second easy week.

After this we move into 3 more weeks of intense training in Part 6 where we discuss Mile pace training (or running even harder intervals!).

If you've missed the previous entries you can catch up on them all at the below links or use the bottom link to go to a list of all my training articles.

Catch you on the trails,


lee woo said...

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Bryn Running

Training diary and musings on running in general.