We’ve all heard it. We may even have said it. “That lactic acid burn… lactic acid is building up and it makes me sore… lactic acid slowed me down…”
Well, lactic acid, or better referred to as lactate is actually an energy source which is critical to conditioning and performance. Lactate builds up in our blood stream as a result of exercise. Muscles actually love lactate for energy. When it can’t use all that is produced it spills over into the blood stream. The point at which it builds up at a rate faster than it is used by our muscles for energy is called the lactate threshold (LT). This occurs somewhere around 60-80% of your vVO2max (the minimal speed at which you hit maximum oxygen uptake). A pretty large range huh?
So, this first means lactate threshold which is commonly confused with anaerobic threshold are obviously completely different. Lactate threshold is most definitely an aerobic process.
There is something else which is very important to note. The way that so many coaches have espoused to improve your lactate threshold is to run for various lengths of time at your LT pace. This is not true! In fact, you have to run at a pace faster than your LT pace in order to improve your LT!
What does this mean to you? All you have to do is run your quality workouts at a pace that is at least at 90% of your vVO2max.
How do you know your vVO2max? Run a time trial of between 1600-2000 meters (6:00-7:00 of running all out). This will work for most age group runners; elite runners will run closer to 3000 meters. Now calculate your pace. That is your vVO2max pace.
Now, take your time and divide by .90. That will give you 90% of vVO2max pace. That pace or faster is ideal for improving your LT. Example: Time trial of 6:00 for 1600. That is 1:30/400. 1:30 divided by .90 = 1:40. LT workouts should be anything 1:40 and faster (all the way up to sprints).
You will find variations in finding your optimal LT enhancing pace. The key is to realize it has to be faster than your LT pace. LT pace for a well trained runner will be close to their 15k (9.3 miles) pace. Therefore, to enhance your LT you have to aim for 10k pace or better. This also means the typical “tempo” run will not enhance LT because it is most often run too slow. A proper “tempo” run should be just about 10k pace.
Bottom line, if you really want bang for the buck, running a variety of fast paced workouts (from your vVO2max pace to sprints) will not only enhance LT, it will enhance economy and vVO2max.
Now, for that lactic acid burn issue. Lactic acid is not a cause for slowing down. It is also not a cause for soreness. It actually appears that soreness in muscles appears to mostly be due to the three following things:
• Neuro-transmitters (chemical) issue
• Muscle membranes damaged
• Inflammation which irritates nerves
So, if you want to improve powerful markers of performance (LT & vVO2max & economy) run fast!
The Running World According to Dean 
Wow! Thanks for the lesson on lactate. I always learn so much from your posts. Thank you, thank you, thank you!
Sandy
Oh it seems to me very fast. In Bilat test of 6 minutes i ran 1540m and my half marathon time is 1h:40 minutes, my marathon time is 3:40h and 5k time 20:58. what do you suggest, i am a long distance runner.
Keko,
Your Bilat test is indeed good. It is much better than your other times and so it indicates that youhave the potential of running much faster at your other distances. It appears that you stamina (ability to hold a pace over a distance) is poor. I would estimate that your 5k should be closer to 20:20, 10k in 42:30, half-marathon in 1:34 and marathon closer to sub-3:20.
Without knowing what you do for workouts and mileage I can only give you very general advice. You need targeted long runs and goal paced runs with a mix of quality runs. I would guess that your long runs and most of your weekly runs are simply too slow. You may or may not need more miles per week but you certainly need more calculated paced long runs (i.e. goal paced) and quality work.
I think you’d benefit from a more comprehensive training program and targeted racing.
i’m too heavy, 1.74m and 85kg. For my long runs i use goal pace runs and my milage is maybe too small, 40 miles a week. In my past i get better results with quality training (famous Bilatt 5x800m and lactate) not with more miles. I think my biggest problem is my weight. Now i start to run at 90% vvo2max 2x10min with 4 minutes rest for lactate and 5×800 @vvo2max pace so we will see.
Keko,
For your height you are stalky. And you are on to something about VO2max. VO2max is a function of our weight (it’s liters of O2 per KG of body weight). So, if you lost weight without losing muscle/strength your VO2max would improve without changing your training. Your body fat % is the more key element when talking about reduction of weight. You only want to reduce fat content. For most people it is as simple as cutting out a snack, or alcohol. Remember it takes calories to maintain your weight as it is. 40 miles a week is plenty for you. Focus more on WHAT you do with those miles versus more of the same MILES.
Coach Dean
Fot time trial test which one is better 6 or 7 minutes?
6 minutes for most runners is just right… only elite can do 7 or 8 minutes.