Luckily, some really smart people decided to take another long and hard look and discovered that lactate is a good guy after all...kinda like Professor Snape or the Batman. If anything, lactate delays fatigue by providing abundant energy during intense exercise.
Furthermore, Lactate Threshold (LT) is now recognized as the key indicator for half or full marathon success instead of VO2Max. LT is defined as the rate in which our bodies are able to clear blood lactate as fast as it is produced. A higher threshold means that we are able to sustain our optimal pace for a longer period of time. Remember in half-marathon distances or longer, our top end speed is much less important than the length of time we can maintain our fastest pace.
To improve LT, we need to A) produce less overall lactate and B) improve blood lactate clearance.
(A) is addressed by improving the amount and quality of mitochondria and aerobic enzymes.
(B) is addressed by training at LT or faster than LT pace to flood our bloodstream with lactate.
Here's how you do it:
1. Find your current LT
There is no single best method for determining your LT, not even at a lab. Use a combination of the following instead:
- Your 10-mile (16 km) time. You can use your most recent 10 km and HM race times if available
- Approximately 80-90 pct Max HR or 75-88 pct Heart Rate Reserve (HRR)
- Perceived Effort - the fastest pace you feel is possible for about an hour
- Via online tools such as those provided by MacMillan or Daniels
2. To improve the number and size of mitochondria
- Go on long runs at aerobic pace (70-80 pct of Max HR)
- Include 30-second bursts of high intensity running during workouts
3. To improve blood lactate clearance
Use the following workouts once or twice a week during training season:
- Tempo: Run at faster than LT pace for at least 4 minutes (up to 20 minutes), recover for half the time (up to 4 minutes)
- 4 x (6 minutes at faster than LT with 3 min jog recovery)
- LT Hills: Run uphill at LT effort for 5:00 then downhill for 1:00 at the same effort. Jog back to the start
- LT Intervals: Run at LT km pace -5 seconds (-10 seconds per mile) then recover at LT pace +5 seconds
- LT -5 seconds for 4:00*, LT +5 seconds for 4:00 then 3 x (LT -5s for 1:00, LT +5s for 4:00) = 23-minute workout
- LT -5 seconds for 4:00, LT +5 seconds for 4:00 then 4 x (LT -5s for 2:00, LT +5s for 4:00) = 36-minute workout
Sources: Science of Running (Steve Magness), Faster Road Racing (Pete Pfitzinger), 80/20 Running (Matt Fitzgerald)