Posted: March 7, 2005

Science of Sport: A Strange Recovery Drink Strikes Me in the Face

The Running Research News Weekly Training Update

Hi Everyone,

It's transformation time. In Michigan, crocuses are climbing through the snow, our streets are navigable by gondola, our trees are suddenly decorated with colorful, song-struck birds.

And those trees - they are as hardy as Kenyan runners! Despite a recent week of severe, un-spring-like weather, with morning temperatures falling as far as five Fahrenheit, the pollards are pushing out buds. But it is of course Acer saccharum, seething with sugary lymph, which is truly stealing the show. Up, up, rises fluid in phloem, eighty or more feet in the air: It's time, the maples are saying, time to be transformed, and their veins are suddenly bulging with a strange kind of blood.

I didn't know about the maples' vascular revivals until this morning, when a slug of sap struck me full in the face as I finished a run. I looked up just in time to have another splash of maple milk decorate my face, and I let the soothing, ice-cold liquid drip down into my mouth, the beginning of post-workout recovery. The strange tree liquor was just slightly sweet, a dilute version of the syrups and maple creams which will soon appear in stores and at road-side stands (if it were thicker, maples would be plagued by a form of atherosclerosis), but it was somehow perfect. Acer's magical re-birth alchemized my legs, wiping out the fatigue I had felt just moments before, and my spirits soared.

Clearly, spring is a time for transformation, and that may be especially true for our running. Fitness can fall during the winter months, and thus our early-spring workouts may be disappointing. Sometimes, we wonder about what can be done to revive running capacity after a few months of less-than-optimal training.

Naturally, a solid plan of attack, with emphases on the gradual improvements of vVO2max, lactate threshold, economy, and max running speed, is in order. In addition, there are certain workouts which create a nice "bridge" between winter's low ebb of fitness and summer's higher running capacities. I employed one such workout this morning before being struck by the sap.

It's the "15-15" session, and it is remarkably easy to carry out. Once you have warmed up and you are feeling physically loose and mentally ready, you simply alternate 15 seconds of fast running with 15-second, easy-jog recoveries.

What exactly is "fast running"? Truthfully, the specific velocity does not matter. All that you really need to do is run more quickly, while staying relaxed, than you would during six minutes of sustained, all-out running (as in a vVO2max test). Since the work interval is only 15 seconds, you'll find this to be quite easy to do. Sure, you may not know what your actual six-minute speed would be, but you'll certainly have the ability to say "I couldn't sustain this pace for six minutes" as you surge through each 15-second rep, and thus you'll know whether your 15-second work intervals are adequately intense.

Although the session revolves around 15-second time periods, using a watch is really a hassle (you end up looking at your timepiece too often, instead of concentrating on the maintenance of relaxed, powerful form), so I prefer keeping track of time by counting strides. If you are comfortable with the idea that you take 90 strides (180 steps) per minute, for example, you know that you will complete 22.5 strides in 15 seconds. That's an odd stride count, so I usually settle for 24 (it's not a big deal if the rep is slightly longer than 15 seconds). I also like to count strides, either off the left or right foot, by twos (2, 4, 6, 8, etc.), as counting each and every stride is too distracting.

For the recoveries, I just jog easily and estimate the 15 seconds, sometimes picturing a second hand sweeping across the face of a clock. I'm very relaxed about this, because I know that my fitness will not be appreciably harmed if some recoveries last a few extra seconds. By staying relaxed and "listening" to how I am feeling, I am also able to start many work intervals "early", before the 15 seconds of recovery are up, which improves the overall quality of the session (it's important not to obsess about doing this, though; the workout is designed to flow along smoothly and happily).

My current state of fitness is rather low, and so I usually begin to feel significant fatigue after ~ 10 work intervals, or about five minutes of the back-and-forth running. I then bless the coach who invented the concept of "sets" of work intervals and cruise easily for awhile, until I feel ready to go again. The workout proceeds in this fashion, with sets containing a variable number of 15-second reps, until a reasonable limit is reached. Your body may tell you when this limit has been attained: Anatomical focal points in your legs may begin crying for mercy. Rational thinking can also be helpful: If you have been running for 45 minutes per day, for example, with smatterings of good-quality running, it would be unreasonable to suddenly embark on a 60-minute exertion, with most of the effort consisting of 15-15 pacing. Acer waits many weeks to begin full production of its life-giving broth, and you have a full season to optimize your performance-related variables.

The only "down" side I have discovered with the 15-15 is that sometimes the stop-start nature of the running becomes annoying. When this happens, I simply stride out at a fast pace for a minute or two, recover with a minute or two of jogging, and then resume the 15-15 pattern. No major harm is done by injecting the longer intervals, even if pace falls off slightly, and variations in interval length can help keep the workout "alive" and interesting.

Why 15-15 - and why not 27-27, or some other number combination? Truthfully, 15-15 is not set in stone, but research carried out by Veronique Billat and others has demonstrated convincingly that the 15-15 is associated with very high heart rates and very lofty rates of oxygen consumption, which of course are good things. In addition, the 15-15 is particularly suited for the early season, when it can be hard to perform longer intervals in a high-quality way. You could call it Quality Training 101 without being off-course.

Instead of worrying about something like the 15-15, could you simply tack on a few extra miles to your usual workout- running six, eight, or 10 miles at a moderate pace, for example - and get a similar fitness bonus? Of course, the 15-15 is preferable to that kind of running, because the 15-15 will have a grander effect on the oxidative capacity of your leg muscles and on the ability of your neuromuscular system to produce powerful running. Those are two key effects which will definitely help you "down the road" - as your training season progresses.

Don't forget that the 15-15 is a high-quality workout, one which can be associated with leg-muscle-glycogen wipe-outs, so please begin your nutritional recovery immediately after the session ends. If you are lucky enough to live in the region of reviving Acer saccharum, position yourself under a limb which contains a small fissure, and enjoy at least a few drops of perfect replenishment - while your worried neighbors are dialing 911.

With very kindest regards,

Owen Anderson