Well today I just ran my first one of these fun runs. I started out pretty quick down the hill and up the hill in my neighborhood so I got my heart rate up to working rate fairly quick. Then I slowed down and kept bouncing up and down as I felt it. All in all I ran for 30 minutes and I put in 3.7 miles.

As you can see my speed was all over the map. I ran as slow as a 10:35/mile and as fast as 5:00/mile. My heart rate closely followed my pace while lagging a bit behind. I have tapped into my lactate threshold level several times during the run, any time you see the blue line go above 83% and stay below 88% I was in my lactate threshold level. But what’s really interesting is that while my current run’s chart looks nothing like my tempo run’s chart from two days ago my averages as very close to each other.

On Thursday I have averaged 80% HRR for the entire run, today I averaged 80% HRR as well. On Thursday my average pace for the run was 8:32/mile today it was 8:36/mile. The two are almost the same. So as you can see they were two vastly different runs which felt vastly different while running but they accomplished the same thing. They got my heart rate up in the lactate threshold zone so I could keep on improving my lactate threshold level. My training plan calls for one tempo and one fartlek run per week for the next 11 weeks so I’ll be doing a lot more of these in the near future but I probably won’t bore you with their details.

There are various types of running that one should do during training to exercise different parts of their body. I’m not talking about different muscle groups I’m talking about different physiological parts of your body. Running performance depends on several things but it basically boils down to three basic items:

1. VO2Max
2. Lactate Threshold Level
3. Efficiency

There are different running paces and training intervals and distances that are specifically targeting one or many of the above three areas. Today I ran a tempo run which is targeting item number two on the list; lactate threshold level.

Lactate threshold has to do with aerobic and anaerobic exercising and a combination of the two. When you run fast your body burns a lot of energy. To burn this energy your body needs oxygen. Lots of it! The more oxygen you can provide the better/faster you can run. When you can no longer provide enough oxygen to sustain a given running pace your body has to turn to anaerobic energy sources and it will start to get energy from anaerobic chemical reactions. Aerobic exercise is when your muscles run on oxygen. Anaerobic exercise is when they run on something else. Your body prefers to run on oxygen as it is a lot more efficient but when push comes to shove and you’re at your peak performance it has to use what it can. So it starts the anaerobic energy process.

So what is wrong with anaerobic exercising? Other than the fact that it’s a very inefficient way to convert energy into movement and it would cause you to burn up your fuel (glucose and glycogen) a lot faster than aerobic exercise it has a nasty byproduct; lactate or lactic acid. Normally your body generates amounts of lactate and your heart, liver, kidneys and muscles all use it and convert it back to glucose (liver) or metabolize it for energy. Unfortunately your body can metabolize only so much lactate at a time. And when you generate more than you use use it starts to build up in your bloodstream as the equilibrium is broken between production and consumption. When this point is reached it’s called Onset of Blood Lactate Accumulation (OBLA). You can only accumulate so much of this lactate on your system before your muscles just give up, throw in the towel and call it quits. They will seize to operate until lactate levels drop back to an acceptable level. This can be a really bad situation when you’re in the middle of a run or a competition. This is why you can see some marathon runners on TV just stopping completely in the middle of a race unable to go on at any speed. Their body shuts down and there is nothing they can do about it at that point they’re already saturated with lactate and they just have to wait it out until their lactate level drops at which point they’re long out of contention. So what can you do about lactate while trying to increase your running pace?

You can either improve your cardiovascular delivery system so you can provide more oxygen to your muscles and they don’t get oxygen deprived and can operate aerobically longer (item number one), you can concentrate on your running form and improve it (item number three) or you can improve your lactate metabolism so your body can get rid of lactate faster from your bloodstream (item number two). And this second option is where tempo runs come into the picture. They make you run and operate above your lactate threshold level so there is lactate buildup in your system. This buildup is gradual and it sends triggers to your body to boost and improve your lactate metabolizing system. During a lactate threshold run you won’t reach saturation but you want to build up enough lactate so the effects of it cause your body to adapt.

Today was one of these runs for me. I ran 5.9 miles (9.5 km) and I have stayed in my lactate threshold level for about 20 minutes. Lactate threshold level is different in different people, this is the whole point of the exercise; to change it and push it upwards. In beginners it’s around 77%-83% of your Heart Rate Reserve while in experienced runners it’s between 82%-88% of HRR%. So I have tried to stay about 80% and below 88% with my HRR during the run and I tried to build up gradually after a 10 minute warm up. You can see that I ran the first mile rather easy and my heart rate stayed low, below 75% of HRR. Then I gradually started running faster and faster and you can see how my heart rate climbed along with my pace.

At the half way point I turned back and I caught a nasty head wind. This is the reason why my heart rate kept on climbing yet my pace was dropping. This is why it’s important to gauge your effort based on heart rate and not on pace. I kept my heart rate high for a while then I started slowing down towards the end to finish the run with a good cool down and you can see that I actually had to run much slower than during the warm up just to reduce my heart rate to a similar rate as the warm up. This is called EPOC, Excess Post-exercise Oxygen Consumption. My body was still going through oxygen just to rid my system of the excess lactate that it has gathered during the middle of the run. This is how you can tell that your tempo run really worked.

All in all it was a superb tempo run and I had great fun out there. The run started slow then built up gradually hitting its peak at the 2/3rd mark then it gradually dropped down again towards the end. This was the fastest I had ever ran during warm up, I was running close to 8 minute mile pace just to warm up which is just unbelievable. Tomorrow I’ll be running a slow 3 mile recovery run after today’s hard tempo session so it should be quick and easy. I’ll do it after work while I take my son to soccer as I’m planning on playing golf hitting the driving range with my buddy at lunch.