|Training In The Fourth Dimension|
By Gordo Byrn
One of the favorite tests of athletes, and coaches, is to estimate an athlete’s functional threshold (heart rate, power and/or pace). These tests are challenging, easy to administer and over in less than hour.
If you are a middle-distance triathlete, racing three to six hours, then there is another physiological point that you want to track – lactate threshold.
There’s been a fair amount of confusion around the use of various physiological terms over the years as cyclists, triathletes, runners and scientists have come together. The merging of CyclingPeaks (Coggan/Allen) with TrainingBible (Friel) appears to have produced a welcome consensus.
As near as we can gather, the chart below pulls everyone’s terminology together. Thanks to Alan Couzens for pulling it together. We had to make some generalizations to get everyone on the same page.
So, the point I am talking about today is your Mod-Hard zone. At the risk of putting words in people’s mouths… (a) Friel Zone 3; (b) Maffetone’s Max Aerobic; (c) Coggan Power Zone 3; and (d) Daniel’s Marathon Pace.
If I am getting a bit too technical for you then the key physiological markers are rhythmic breathing without the burning in your legs that you will feel after a few minutes at functional threshold. That’s why many people call this point “moderately-hard”. You’re working but you have a decent shot at holding for a few hours when appropriately trained and fueled.
Ever wonder why Mark Allen and Phil Maffetone refer to this point as “max aerobic”? Well, in physiology terms, once you go past this point, you will start to materially recruit your fast twitch (non-aerobic) fibers. The reason Mark’s philosophy is so effective is that by staying under your “MAF” heart rate, you will be training the fibers and energy systems that will dominate your performance in any endurance event.
So that’s the opener – quite a bit of verbage just to introduce LT!
Why does LT matter?
As a middle distance triathlete, it represents your best-case scenario for average intensity across your race duration. Given that your fastest race will result from lifting your average intensity on the run, this physiological marker becomes an important point for your bike training as well as your race plan.
Understanding where this point lies, and building the endurance to ride at this point, is an important part of your race-specific training. Further, doing specific training to track your endurance at LT power/pace will enable you to make better pacing decisions and increase the chance that you blaze your run split!
So here are a few of my favorite workouts to help you do just that.
A. Half Ironman Simulation
Run 45 minutes split between an easy and a Steady effort (track HR and pace)
Ride 2:15 inserting a two-hour main set (40 min Steady / 20 min Mod-Hard, repeat without a break)
Run 45 minutes hold Steady pace from first run and note HR
Post workout, remember that Mod-hard is a proxy for Half Ironman effort. Nominally, the workout contains “only” 40 minutes of Half Ironman effort. If your heart rate pops significantly on the second run then you’ll need to dial your bike efforts well back on race day.
Elite Training: I have done up to five hours of 40/20s. I have to admit that I was only tough enough to do that workout once and was too torched to run after. The two-hour main set is repeatable without excessive fatigue, it’s what I recommend for athletes of all abilities.
I picked this pattern up from Dave Scott and it is an effective way to work multiple energy systems on the bike. The set is really simple – 12 minutes Steady, 3 minutes Mod-hard. You roll that pattern up to six times with variations in terrain, position and cadence.
Elite Training: For long course triathlon, I would build up to 2x90 mins of 12/3s – that’s three hours worth of main sets within a five-hour long ride. More normal is (3x) 12/3 as a standalone main set. It breaks up the monotony of long Steady training and also trains the capacity to recover at a decent work rate.
It takes a lot of discipline not to drill it once your HR gets up. Training yourself to mentally handle backing off is a useful skill to have in your portfolio.
This is another one that I picked up from Dave, with six Kona victories, it’s not surprising that he knows a thing or two. The workout started as a running main set that I used in my specific preparation for IM Canada 2004.
Warm-up with 30-40 minutes that build to Steady HR then:
3x25 min on 5 min Easy recovery
#1 -- aim to hold slightly under LT watts (Mod-hard effort)
#2 -- hold the lower of: (a) LT watts; and (b) LTHR (LT Heart Rate)
#3 -- hold LTHR and note avg wattage
If you don't have a powermeter then use perceived effort -- remember not to force HR over perceived effort, especially early -- give yourself room to outperform
Note this workout adds up to 75 mins of Mod-hard effort -- a proxy for Half IM effort -- have a reality check afterwards if this is really Half IM effort. Nearly everyone tries to bust out Threshold on their first attempt -- 75 min of Threshold with short recoveries will get your attention!
The main set makes it pretty clear if you ride too hard early (especially if you run a powermeter and are strict with LTHR cap at the end).
If you know your FTHR on the bike and are unsure of your LTHR then use breath markers and cap yourself at FTHR less 12 bpm. This may end up a little below your LT but that is perfectly OK for this session and far superior to riding 75 min slightly over LT
Elite Training: When I was in 8:29 IM shape, I was able to hold 3x45 minutes at Half IM watts without crossing LTHR. Similarly, the 3x25 run training was done at Half IM pace without crossing LTHR.
What is the Fourth Dimension?
These workouts offer you an insight into your performance over time. What most athletes (elite and amateur) will notice is that their heart rate rises significantly as the workout progresses // OR // if heart rate is held constant then there will be a big reduction in late power/pace for a given heart rate.
Given that running well is a requirement for triathlon success, the workouts will enable you to find the bike effort that sets you up for a blazing run split. It takes a lot of humility to swim and bike at an effort that enables us to run well.
If you are experiencing significant fade (power or pace) then you are endurance limited (regardless of what your FT performance indicates). For near term racing, you will need to dial your bike efforts down. For long-term development, you will need to focus on sub-LT improvement. You do not, yet, have the capacity to utilize your higher intensity fitness.
When you are able to roll these workouts with minimal fade and speedy recovery, you will know that your endurance is well established and it will be relatively safe to incorporate some challenging sessions that focus on your LT performance.
Be Strong at the End!