Lactate treshold test, input needed

A female friend of mine recently did a lactate test. She only got the raw results and I did put all this in a sort of scheme ( Excel file , 3 different curves)

The grafics can be found at this link :

http://users.pandora.be/lyotroadracing/lactaate.xls

Some details :

*protocol : every 5 minutes , 25 Watt was added.

* It was a submaximal test , not a maximal test. The last zone (the 6th figure) has been estimated by myself and is not a real test result. I just thought this figure was more or less the logical consequence (if you prolong the curve) . I'm not sure if this is scientifically correct though..

Am I correct to think that :

*The lactate treshold can be put at 4mmol in her case (there's a slight bend in the curve at that point) which corresponds with a heart rate of about 157 BPM.

*The form of the curve suggests that her endurance system is insufficiently developped since she almost immediately reaches 2mmol while cycling at the first stage of the test.. Also, the curve is rapidly increasing, instead of showing a long base in which she keeps a relatively low Mmol output..?

* the key in training improvement should be focusing on low intensity rides to make progress in endurance at first (ca.120-130 heartbeat) .


Are there other elements that can be said about this test ? Or specific training advise ?

ps : training with power output devices is , unfortunately, not an option in this case..

best greetings

I just watched a similar test performed by a sports physician on a willing subject as a demonstration at our monthly club meeting. He used a 25 watt step every 3 minutes. After the test, his assistant plotted the points for us to see, and then the doctor marked the chart and discussed two key points.

First, he defined the "LT" point as 1.0 mmol/L over the resting measurement, or 2.9 mmol/L for our subject. This was at point #3, or at 175 watts. Then the "AT", or "Anaerobic Threshold" at the deflection point on the curve. (He noted that many people and studies call this second point the LT). For our subject, the deflection point of the MZ curve was just below 4.0 mmol/L (235W, 157 HR). The doctor mentioned that 4.0 was commonly considered the point, but that it really could be anywhere between 2.5-5.0, depending on the individual. Our subject continued to suffer up to 13.6 mmol/L (ouch!), at around 350 W, no doubt due to the number of club members looking on!

For your friend, believe that the deflection or break point of the MZ vs power curve would be closer to the 3.1 MZ value (175 watts, HF 145). At 4.0 mmol/L, your friend is already on the steep slope upwards, so I doubt she could hold that level very long.

Note I'm not an expert by any means and would welcome discussion.

It kinda seems like they started the test too high for her, as there's very little linear portion to the curve at all. What's her background and fitness level?

Yeah, it's indeed strange that she immediately obtains 2mmol at 100 Watt..

She does cycle a lot though. I'm not sure, but I estimate she must have done about 5000-6000 km's (4000 miles) this year alone.. I take it she didn't do enough slow endurance trainings at the start of the season, yet was mostly focusing on rides at an average of 140-145 BPM ... The last couple of months, she's been getting into slower rides more often though..
But she's definitly fit, as she participates and finishes at long tourist races, like for example 3 Ballons / Marmotte / Maratona Dolomites (100- 140 miles )

thanks for the clarification on the AT & LT .. Overhere in Europe (and I'm excluding the UK, as Ric uses the term all the time) , AT almost never gets any mention. The only thing taken into account here, when dressing up a training scheme is LT . I agree the 4mmol figure isn't decisive , yet , one should look at the bend.. In this case, I find it really really difficult, but I still guess it should be around 4 mmol...

It's a pity it wasn't a maximal test though..

From my exprience and perspective you can get a pretty right on idea of your lactate threshold heart rate and wattage output by doing a 30 minute all out effort. Once you have the ability to pace yourself for an effort that long you'll find that by analizing the data after the workout you'r averages will be your threshold.
I had a VO2 max test a couple of years ago and before the test I told the doctor that My threshold heart rate would be between 155 bpm and 160bpm. The machine pegged my threshold at 159 bpm.
High tech is not going to give you much better results than that.
Eric

Along with many others, I use the exercise intensity corresponding to a fixed blood lactate concentration of 2.5 mmol/L as the definition for LT. For her, this would be a power of just over 150 W (eyeballed from the graph).

The power corresponding to a fixed blood lactate concentration of 4 mmol/L is correctly termed OBLA, for "onset of blood lactate accumulation" (which in itself is a really a misnomer, as it is really closer to the "onset of CONTINUAL blood lactate accumulation").

The fact that all of the baseline values appear elevated is a bit concerning, as it suggests that she was excessively nervous/stressed, the initial power was too high, and/or that the blood lactate analyzer was off. However, the fact that the first three values are all similar before the curve takes off is reassuring, so I wouldn't worry excessively about this point.

In terms of training advice, I definitely suggest trying to read as much into the results as you have done. Blood lactate concentration is a good indirect marker for metabolic events in exercising muscle, but it is still only an indirect marker nonetheless.

sorry, I was confused. I meant the exacte opposite : LT never gets any mention in Europe, it's always AT people are talking about here.. (and mostly that's defined as the 4mmol figure)

thanks for the information. What do you mean with blood lactate concentration being an indirect marker ?
greetings

Just did some testing and had one subject whose curve was pretty normal while one went up, came back down then went back up again. Was nervous about the blood sampling so perhaps a bit of aprehension was affecting his test.

There was a discussion about the figures at the Sport Science site where they mentioned monitoring the lower levels was more important for tracking improvement.

Hamish Ferguson

Slightly OT .. where did you get it done?

B

Two questions:

1] Is power at OBLA the same as threshold power?
2] Should intervals like 2 * 20 be done at 2.5 mmol/l power or 4.0?

1) Power at OBLA would be similar to the power at what I call functional threshold power, but would be 10-15% higher than power at LT (as it is properly defined). The reason that I say "similar" is that your functional threshold power is essentially your maximal lactate steady state power, and the latter has been shown to occur at different lactate concentrations in different individuals. The classic 4 mmol/L OBLA is really just an average (and probably a bit on the low side, at least when it comes to cycling/cyclists).

2) Closer to the latter, for sure.

Pretty much just that...

By far the most important determinant of performance is the ability to closely match energy production to energy demand in exercising muscle. Blood lactate concentrations are related to this balance/imbalance, but only indirectly so. When the day comes that it is possible to measure muscle energetics non-invasively using a portable hand-held analyzer instead of a $1M magnetic resonance instrument, measuring blood lactate will become obsolete.