Have you ever worked out to the point where you started to feel a slight burning sensation in any part of your arms or legs? Well, the sensation–that burn–is coinciding with an increase in lactic acid production; the burning feeling actually comes from micro tears caused during hard runs. When your body is not getting a sufficient amount of oxygen to power the muscles, lactic acid starts to build up to do so. During harder workouts (think: quick reps or fast-paced workouts), this is exactly what happens. Your breathing tends to become shallow (you may even hold your breath) and this will speed up the build-up of lactic acid. When this happens, your muscles feel like they are on fire and have turned into cement blocks all at the same time. Note: There’s much more science that goes into this if that wasn’t obvious already. And here’s another kicker: it’s actually the byproduct of lactic acid-hydrogen-that is really to blame for your muscle fatigue, but the focus should and will still be on combating lactic acid.
Although this wasn’t because of lactic acid, LA can definitely cause runners to feel like this. This is me cramping at the end of a 12 hour ultramarathon.
Have you ever heard of Aerobic (oxygen) vs. Anaerobic (without oxygen) running? Aerobic workouts mean that the individual is getting enough oxygen to sustain their running or other exercise. So, generally speaking, these runs include your long slow runs, your morning jogs, and maybe even your daily or weekly 3-5 miler at easy-moderate pace. In an anaerobic workout, a person is not getting enough oxygen and so lactic acid starts to build up during these exercises or when your body starts to go anaerobic…”Wait. When my body starts to go anaerobic? It can do that?” Yes! You can start out a workout at a good moderate pace, and you’d be using your aerobic system, but when you start to add speed, you are switching to using more of your anaerobic system. This results in your heart rate increasing and your oxygen intake lessening, thus producing lactic acid at a quicker rate.
“So then do I just not run fast paces so that I don’t have to slow down or stop during a workout?” The short answer is a resounding, “No,” but the long answer involves what you should do instead and why you should do this. I was recently asked the following question: “How can I run a faster 10 mile run?” My response, in short, was to focus on shorter, faster runs and not worry too much about getting close to that 10 mile mileage point. So the answer to both of these questions is to incorporate harder, generally more faster-paced efforts or entire runs on a weekly or biweekly basis (this could be slightly more or less–all depends on your goals and fitness level).
So, in no particular order, here are the…
Workouts to Combat Lactic Acid (or, in other words, “…to prevent Lactic Acid from slowing you down“)
#1 Tempo runs/Lactate Threshold Runs
I do these workouts a lot and you’ve probably heard of them before, but while they may be used interchangeably it should be noted that a tempo run is just a popular type of lactate threshold run; there are others.
When your body gets to the point where shortness of breath starts to kick in and your muscles are getting heavier, you have likely reached your lactate threshold. When you reach this point you are now running anaerobically which is much more difficult to maintain. If you “go” anaerobic in the last mile of a 5k or even a 10k, this is okay, but when you’re trying to complete a training run or a longer-distance race, you don’t want to be running beyond your threshold (anaerobically) for too long.
Lactate threshold (LT) running is at a pace that is faster or harder than your regular easy run pace, but slower than your 5k or 10k race pace. So if you’re 5k pace is 7:30 a mile, your threshold pace may be between 7:45-8:15 pace (depending on your fitness). The mileage or amount of time you run a threshold run really depends on your training and goals, but generally you should shoot for a minimum of 2-3 miles at threshold pace, more though if you are training for a time goal for a half-marathon or marathon. Threshold runs are a great way to gain aerobic fitness and are great runs for all race distances.
Tempo runs are slightly different in that they are generally longer. Same concept can be applied, but a tempo run is generally referred to a run that is at LT pace for a longer period of time (35-40 minutes at least).
Yes…the word “Fart” is in there. Go ahead. Get your laughs out. Fartleks are probably my favorite on this list. “Fartlek” means “speed play” in Swedish and it really is just that: pure fun and play that can be completed anywhere. Track. Trail. Road. Waterfront esplanade (Gotta love Portland). They are an incredibly versatile run that can be either distance based or time based and you set the marks!
Let me explain:
For a distance-based fartlek workout on a track, you may decide that you will run the curves at a moderate pace and you will run the straightaways at a harder effort and continue that alternating for x number of minutes or miles. On any other type of surface, you can have the distance at which you alternate be a city block; a coffee shop to coffee shop; tree to light signal; etc. So easy, right? You set the rules. The key is that you are alternating between moderate effort and fast efforts without walking or stopping. So while you are running that 45 seconds or that 100 meters at a faster pace, you are switching to anaerobic and your body is producing lactic acid. Then you slow down slightly and start to catch your breath, but that lactic acid hasn’t gone anywhere and so after your moderate pace time or distance is up, you’re back at the faster pace, forcing your legs to run while they are being filled with lactic acid.This is getting your legs used to “running (while) heavy” and so when this happens during your next 5K, 10 miler, or half-marathon, 1) You won’t feel the effects of lactic acid build-up as early on and 2) you are more accustomed to the feeling when your body does start to accumulate lactate and can sustain a longer mental push.
Just an example I found online of a possible Fartlek workout.
#3 Long Run-Fast Finish
I LOVE the long run. I get some pretty great thinking done during these hours on the road. No matter what kind of runner you are, you should be incorporating a long run at least once every 2 weeks, but once a week I think is a better option. It’s important to note here that one person’s long run isn’t necessarily the next person’s long run. During my first 2 years of undergrad, I would have said that a 7 miler was my long run, but fast-forward to the present and a long run for me is usually 17+ miles. Again, it all depends on you and your fitness level. So what is a “Long Run-Fast Finish” and why should you do it?
Marathon coaches and runners will likely tell you that it’s not enough to just get close to marathon mileage in your long run. Sure, that will get your body and legs used to running for 20 miles or so, but what about those who have a time goal in mind? After the 18-20 mile mark of the marathon or even the 8-10 mile mark of the half-marathon, the race takes on a whole other level that can significantly cause your pace to slow. You may have experienced this in a race before. You’re cruising along at your goal 8 minute pace, feeling good, when suddenly at some point past the halfway mark, it all starts to fall apart for you. This can happen for a number of reasons, but one of them is that your body reached its lactate threshold.
So let’s say 10 miles is your long run. What you can do to fight back against lactic acid (although lactic acid really gets a bad rap and is actually quite vital for exercise), is run the last several miles at a quicker pace, maybe near goal pace. So during the first week you try this, you may try to run miles 9 and 10 at closer to goal pace (this won’t be easy after 8 miles of a slower pace) and then during the 2nd week you may try to run the last 3 miles at closer to goal pace. Don’t try for running the entire run at goal pace or else you’re looking at a longer recovery period, but doing this kind of long-run variation will certainly get those legs used to keeping a hard-effort pace even after running for so many miles.
The dreaded “H” word. If you ran cross country, track, or played certain sports in high school, you probably just cringed when you read what #4 was. But as exhausting and relentless as hills are, they are immensely valuable for runners. Depending on the grade (incline or slope) of the hill, lactic acid can almost immediately start to build-up as your breathing becomes quickly shortened. Why does breath become short so quickly when running up a hill? This is because your muscles need oxygen to function properly and when you are running up a hill, you are requiring many more muscles to be functioning all at once, all demanding an increase in oxygen levels which just isn’t there. So lactic acid builds up quickly and your legs and lungs are searing by the time you get to the top or finish your set. This is why hills are a fantastic way to prep the body for better utilizing lactic acid and mitigating how much it slows you down, in addition to building lower body strength.
When running up a fairly steep hill or doing hill repeats (generally on a shorter hill, but longer hills work too), your body is producing lactic acid as we discussed. When you get to the top, you gasp for air and almost immediately start to feel life back in your legs. Well that lactic acid is still there and you are either running further out or running back down the hill to repeat this process. Continuing that run after the hill climb is what is vitally important to get the benefits of hill running. Just like with fartleks, you are forcing your legs to continue to move even after lactate threshold has been reached. When you run back down the hill or when you continue your run after the successful climb, your legs are getting used to running when heavy. If you are doing hills repeats, you are really teaching your body to adapt to deal with the ever-present lactic acid levels. The added bonus here is that if your race or new route has hills to climb and descend, you have much more leg strength, mental strength, and overall capability to get you through the section. Remember this: proper posture is important; avoid slouching.
Now get on out there and get your fartlek on! Show lactic acid who’s boss!