I’m not sure if my tempo and vo2 seesions should be preceded by a more intense warm-up to avoid high cardiac drift between each interval? The HR difference between first and forth interval is about 20bpm. Could you share your experience?
As always, this depends on your goal. If you want to do long threshold type efforts while already at/coming from threshold HR you can add the warmup. For doing a proper tempo/sweet spot session it wil probably not add to the training effect. May even keep you from finishing the last effort strong.
HR drift is actually to be expected when approaching LT2/~FTP as you do in the shown example. HR drifts as you near your bodies lactate clearing capacity and that is exactly what you want your body to experience and improve from in threshold training.
Keep in mind that hydration, sleep, fatigue, matches burned etc. may all have an effect on how HR behaves in individual sessions. This makes it powerful for gauging your reaction to training but you should also place it into context which can be difficult.
For Threshold workouts:
What is your heart rate at LT2/MLSS?
That should be the limit (+1bpm), and then you should reduce power to ensure you don’t exceed the “limit”. As you get better at this, you will see your power increase while you keep your HR below threshold.
My hart rate at LT2 is 161. I’ve reach these values during last interval avg hr=153 and max hr=159.
It looks like everything is correct. I thought the tempo training session should be adjusted to ensure the same level of heart rate and power during each repetition. I was wrong.
Unfortunately this is what I learned quite recently I was training rowing in the past but nobody care about us and only repeated “you have to train harder over and over again”.
So old style
Train easier, be more consistent and put in more hours will get you way further. More load is the key factor, but the load must be manageable. Lower intensity, more time and consistency will make you stronger.
FTP is not the same every day, so you can’t target the same power on the same interval each time. Some days you’ll be above FTP and feel good, and other days below and feel like a struggle. That’s why there’s a range (90-105% is threshold). This is why heart rate is so important; it’s the response to the workout (at the time) that shows how you are performing.
HR could be below the LT2 level on the first interval, but then you increase the power to get to that point. Feel on the first should be "hard, but I can go harder). Feel on the last one should be, “I gave it everything”.