I love all the data - if I ever do this again I'm wearing my Garmin HRM and footpod to get cadence and a full HR trend instead of just at a few spots.
Test Description - After a baselining period taking readings at rest and a slow walk - the test goes 8 min at each speed, each row has the readings at the end of this 8 minutes, 2 minute rest then start next speed. At the end there were 1 minute intervals harder and harder until I was done to get to VO2max.
Min...Road Eq..vo2 ...HR ....Lactate... Breath/min...Notes
0................... 5.0 .... 47 .....0.9.... 25
8/2....9:55.... 29.7 .... 85 .....1.2.... 33.........50% mile Pace
8/2....8:20.... 36.2 .... 122 ....1.1.... 35.........60% mile Pace
8/2....7:11.... 44.2 .... 140 ....1.4.... 39.........70% mile Pace
8/2....6:20.... 49.8 .... 153 ....2.6.... 46.........80% mile Pace
8/2....5:58.... 54.2 .... 160 ....3.8.... 48.........85% mile Pace
8/2....5:38.... 59.4 .... 169 ....6.6.... 50.........90% mile Pace
1......5:58.... 42.6 .... 160 ........... 51
1......5:37.... 56.3 .... 167 ........... 51
1......5:19.... 62.4 .... 171 ........... 51
1......5:04.... 64.8 .... 174 ....9.3.... 55..........VO2max
My initial thoughts looking at it:
- VO2max ~65 seems about right - looking up my last (and only other) VO2max test (9/2007) my VO2max was measured to be 64 - max VE 126.7 l/m in 2007 vs 128.7 today so 1.5% more O2.
- 2:2 breathing pattern would be 45 breaths/minute assuming 90 cadence - that would sure be running slow - don't think I'll be using that as a speed indicator in racing. I find it interesting the breaths/minute changes very slight between 6:20 and 5:58 pace - not so precise an indicator at all.
- Using some benchmarks from Daniels Running Formula for Threshold speed:
Threshold Lactate ~4.0 = 5:56.
88% VO2max - 57 VO2 = 5:47.
- MP lactate I understand from Eric is typically in the 2.5 to 3.0 range which makes 6:12-6:21 mpm range for me (2:42.5-2:46.5) - short of my goal 2:40 marathon pace of 6:06.
- Heartrate data doesn't seem to correlate to my training heartrates. Big disconnects. The HR in the lab showed around what I see at Marathon Pace for what appears to be Threshold and what I use at Threshold (170ish) is far above Lactate 4.0. Guess I'm discounting the heartrate data as useful until I can find some explanation that makes sense why it is so different from what I see on the road.
- As I happenned to have the Daniels Running Formula open I'm noting "individuals show vast variation from this 4.0 threshold value. One runner might maintain a steady blood lactate concentration of 2.8 and feel same degre of stress as another runner who has a steady 7.2." So I'll take it all with a grain of salt. Still interesting stuff..
Error Analysis
Weight:
- On scale after the ECG cable was hooked up - adds ~1 lb - so actual weight closer to 157 vs 158.
- On treadmill probably supporting 1/2 the ECG cable as well as a helmet tube holder - total together ~1 lbs extra weight.
Impact - pretty small - typically 1 lb ~ 2 sec/mile so MP potential 6:10-6:19. Also VO2max would be ~0.5 higher.
Temperature:
- Lab temperature was recorded on the test results to be 72°F. Per runworks/calculator (6th option down) at colder than 60°F the equivalent marathon speed would drop 6 sec/mile - so MP potential at less than 60°F would be 6:04-6:13.
Time-Lag:
- Each segment was 8 minutes. Looking at my most recent training run at ~Threshold pace (3x3 miles at ~170 bpm with 5 min rest between on 11/26) - the heartrate flattens out after about 1.5 miles or 7 minutes, about 1/4 mile quicker for the 2nd and 3rd intervals. Conclusion: taking the HR readings 8 minutes into a constant pace should be pretty representative.
- Another time-lag issue I heard discussed while I was on the treadmill - there is a 2 minute lag between lactate levels from the muscles to lactate levels in the finger where the blood is drawn - I think this explains the very last Lactate datapoint - although taken after VO2max - the lactate level probably corresponds to a couple minutes earlier or 2 data points to the left - then it kinda lines up with the rest of the curve.
Still the HR levels are a mystery. I can hold 170 HR for 10-13 miles in races so that heartrate should be around threshhold pace (by the 1 hour race pace definition approximation of threshhold pace) - but this test shows 7+ lactate at that HR and the 4.0 lactate points is far lower than this - closer to 160 HR. Makes the heartrate data suspect - but I don't know how to get better HR data than an ECG. It could be that I run my marathon pace with lactate levels in the 3.5-4.0 range - that would be a bit of an outlier but not unheard of - as mentioned above Daniels has seen 7.2 for Lactate Threshold - could be I'm THAT guy.