From your training schedule, that is… LSD—Long Slow Distance—is one of the cornerstones of running or walking training. But should it be?
To some extent, the answer is a resounding... maybe. LSD does have its place. Three places, actually:
Long slow distance is a great way to build endurance for short races like 5ks. There’s no way you’ll be able to train for more than a few minutes at a time at your 5K race pace, so long workouts at any pace won’t specifically prepare you for the rigors of 5K racing. That’s not to say that long workouts aren’t importnat for 5K training. They are. But you can get away with long slow workouts if you’re only planning to race 5ks.
LSD is also good for jumping up to a new long-day mileage level. For example, if you know you need to do 18- and 20-mile workouts to prepare for a marathon, but aren’t physically and/or mentally prepared to go that far at or near your marathon race pace, then it’s okay to go a bit easier until you’ve become accustomed to the new distance.
Finally, a long, slow distance workout is okay if you know you need a long day, but are too tired (or perhaps beat up from a Saturday morning race) to get through your long one at a more ambitious pace.
But marathon training—in fact, training for any race distance—has a lot to do with specificity. To be ready to race you need to specifically prepare your body for what it’s going to experience on race day. If you’re racing a 5K, that means doing a fair amount of tempo and interval work at or near your 5K race pace.
Predictably, the same principle applies to longer races as well. But for some reason, a lot of athletes (and, I hate to say it, even some popular running coaches) forget about specificity when it comes to the longer races. They think it’s okay to lollygag their way through all of their most marathon-specific workouts— those 18- and 20-milers—at a pace that’s two to three minutes per mile slower than their marathon pace.
Well, maybe it’s not a popular thing to say (sort of along the lines of the Great Triad: eat your spinach, brush your teeth, wash behind your ears...) but long slow training prepares your body for one thing: long slow racing. Perfectly acceptable if you’re training for your first marathon, but once you’ve done one of them, what’s the point of doing any more slow ones?
If you’ve made the decision to race a marathon (or even a half-marathon) instead of just getting through it, you’ll have to get your body and mind used to covering significant distances at or near your race pace.
That doesn’t mean you have to do weekly 20-milers at marathon pace—to do so would likely push you over the edge into overtraining. But it is important to do frequent 10 to 15 milers on-pace, and even to occasionally bump those up to 18 to 20 mile efforts at marathon pace.
It all comes down to “fuel efficiency.” You see, our bodies really love to burn carbohydrates. They’ll burn fat alright, but only if there’s plenty of oxygen around—and that may not be the case if you’re racing hard enough to significantly affect your breathing.
Being a “carbo burner” is okay for 5K and 10K racing. But our bodies simply can’t store enough carbs to get through a marathon. If we try to burn a high percentage of carbohydrates we end up “hitting the wall.”
One solution is to do very slow marathons. This will work, since going slow allows our muscles to burn a higher percentage of fats which, in turn conserves carbohydrates.
The other solution isn’t quite as easy but much more rewarding: Teach your body to burn fats at faster paces by running or racewalk- ing at faster—near-marathon—paces on your long days. The result is vast improvement in “metabolic machinery” like metabolic enzymes, capillaries, mitochondria and muscle triglycerides. And these, my friends, are the keys to PR City.
See you on the roads!