If I had to pick one reason why my race times have improved in the last two years, it would be the regular lactate threshold runs in my training.
Without getting too technical about it, your lactate threshold is the point in an intense physical activity where your bloodstream starts to accumulate lactic acid. You’ll have seen the effects of this most graphically when a middle-distance track athlete starts to ‘tie up’ in a sprint down the home straight – the legs get heavy and the head rolls from side to side.
You can increase your lactate threshold, and therefore go harder for longer, with a regular run that includes at least 20 minutes at a controlled, sustained pace that feels slightly hard and uncomfortable without ever becoming a reckless sprint. You’ll find it tough and you might start to dread it, but you’ll be as strong and fast as a horse after it, and these days any reputable marathon training plan will include them.
For most of my running years my threshold sessions were fairly haphazard; once a week for the middle four miles of an eight-mile run I simply ran faster without keeping track of how fast that was. I only started doing them properly early last year when I discovered Daniels’ Running Formula, which includes a table that calculates an optimum lactate threshold pace for you based on your previous race time. A spring spent on Daniels’ Red Intermediate Plan got me in great shape for summer marathon training.
My current marathon training guide, by Pfitzinger and Douglas, draws on Daniels and has a specific lactate threshold phase in weeks 6 to 10 of the 18-week schedule I’m using. Recently this has prescribed to me a weekly run of 10 miles during which I run 5 or 6 miles at a pace around halfway between my 10K personal-best pace and my half-marathon personal-best pace.
If you keep a log of your training – and you should – then looking back over your lactate threshold runs is a great way to see your progress. Two months ago, at the start of my current Dublin Marathon training, I was struggling towards the end of a four-mile session. Now, though, I can see out five miles at a slightly faster pace and still feel like I have something left in the tank. Lactate threshold runs will turn you into a faster runner.
For my lactate threshold runs I have a four-mile parkland loop – two miles on tarmac and two miles on grass – where I have enough space to focus on running hard without worrying about colliding with walkers or tripping over dog leads. The mental focus is important: running at a sustained hard pace demands some concentration. My parkland loop has two hills in it, which adds to the rock-hardness of this workout.
Also, because I use this loop specifically for such a hard session, I almost subconsciously run harder and faster on it than my prescribed threshold pace – although, as I said, it shouldn’t be an eyeballs-out madcap dash. I definitely recommend finding a regular spot for your lactate threshold runs which you don’t use on your long runs or slower recovery runs. Make it your special rock-hard route.
With regular lactate threshold runs as part of a proper marathon training plan, you’ll be smashing PBs left, right and centre.