Looking for some input/guidance. I’m prepping for a big race in May having done no racing for about 8 years, but a fair amount of racing experience over the last 30 years. 60 years old.
I’ve been doing mostly zone 2 for the past few weeks and upping volume steadily. 10 hours per week for last 3 or 4 weeks.
I have been introducing a few higher intensity sessions (cautiously).
Today I completed 4 x 8 minutes at 235 watts. I estimate my FTP to be around 215 watts. So this makes it 109%.
Although I could feel the intensity in my legs my heart rate only came up relatively slowly. The effort only really felt hard (say RPE 8.5 out of 10) for the last 2 minutes of the last interval.
Interval 1 to 4 were avg HR 138, 140, 142, and 145.
I would say my LT2 turnpoint is 150 based on long years of experience and RPE. My max HR is 164 and my resting is 38.
My thoughts are that these intervals should be conducted at a HR at or above my LT2 to get a VO2 max style benefit.
What do you think - should I just keep cranking the watts up until it drives HR up higher every time?
Am I just lacking confidence with my FTP and it should be higher?
Am I just very good at supra-threshold efforts?
Am I overtrained? (I don’t think so as I did these intervals a couple of times before with the same results)
or …?
8-mins is close to the longest interval for VO2 work. You don’t mention your recovery time, so that’s also important in the context of intervals 2, 3 and 4.
See next comment.
If you have a large anaerobic contribution to your efforts, then it could explain why these didn’t feel hard enough; going on your comments on HR relative to your perceived RPE.
BTW, 4x 8min are usually associated with threshold work, so sub-maximal, where you’re still in control of HR and breathing.
Rather than just upping the %age across the whole of the interval, consider making each interval a hard start. i.e. Up the cadence and push the first 30 seconds at, say, 150% FTP and then back it down to 108 - 110
See how that affects HR and breathing.
Or ditch the power target altogether and simply ride so hard that you are breathing like a fish out of water for the duration of the interval.
I understand the point, but I doubt that I have a high anaerobic contribution. I have never been any good at sprinting (maybe a puncheur).
I am also seeing slightly lower HR during my long zone 1 (1 or 1.5 hour) turbo sessions even though I have raised the power by 10w. Along with this, my HRV has gradually been creeping up above the normal range and my overnight Resting HR is stable or slightly lower.
All of these things would indicate improved aerobic fitness, but they could also indicate overtraining so I am a bit cautious about what to conclude.
I notice you mention an estimated FTP. My guess is that your real FTP is higher than you think. In your position I’d do an FTP test – it would help remove some of the guesswork.
When I was fitter than I am at the moment I found hard starts really useful. Xert has several, and because of the metrics they use it starts high and reduces smoothly. May be possible to make something close to that with enough segments, rather than a simple ramp. Part of a completed workout here: (5 min intervals)
Yes, I think that you may be right - ftp might be higher.
I tried to do a test a week ago and failed for 2 reasons.
I overdid the 5 minute effort (test done on mywhoosh has a 5 minute pre effort to reduce anaerobic contribution and
2.. I had a minor mechanical problem which put me off.
I might try again tomorrow as it’s a rest day today.
4x8 intervals should be done between 95-100% of your FTP and regulated by heart rate, allowing no more than 1 beat over. The RPE of 8 is correct for this type of session. You should do an FTP test—it doesn’t have to be 20 minutes; you can perform a ramp test on MyWhoosh (I recommend the 150s protocol, increasing 25w every 150s. Do a 5/10 minute easy warm-up and start the first step at 100w). You should also indicate what the recovery between sets was. Regarding the heart rate you’re reporting, it’s normal for the first one to be lower because the aerobic pathway probably isn’t fully activated yet.
Those sessions don’t need to be preceded by a 30-second effort at 150% of FTP because that’s not their purpose. If activation is needed, it should be done during the warm-up.
This looks mostly answered already, but your FTP is probably not 215 based on your HR and description of RPE.
That said, at this time last year I was almost purely aerobic in fitness strength, and I would not have had a chance of being able to finish 4x9min @ 109%. This year I’ve switched massively to more anaerobic strength, and could definitely complete 4x9min @ 109%.
Maybe slightly off topic, the 4x8min model most likely comes from the seminal Seiler study - it’s 8 min at 80% of peak power output, with one minute recovery. PPO is defined as the max 1min power from a ramp test - start at 3w/kg power, then 1min steps at 25W
Doesn’t that Depend on the athlete fibre type? I’ve been doing fast start intervals and they seem to be working. My aerobic threshold is only 170w but I’m a fast twitch athlete. I jump high, throw hard and have a 1.3kW sprint at 41yrs at 73kg with no sprint training.
Gemini 3pro guidance says my type IIx fibres need the fast start to come online and then stressed to be more aerobic long term
