PeteHski

The problem with sweet spot intervals is that they are relatively high on fatigue. They can work well on a low volume training plan, but if you are moving toward a high volume plan then they might burn you out in the long term. I actually do them quite often, but only on a relatively low volume plan. For example I might do a 1 hour climb with tempo/sweet spot intervals instead of a much longer Z2 ride when I don’t have the time. Basically I find 1 hour Z2 rides relatively unproductive.

While you might not ride at VO2 max in your events, I believe it plays a part in your endurance power and there is some evidence that it may help to slow down the natural decline in VO2 max with age. I read about a study of older cyclists and those that avoided high intensity efforts had a significantly larger drop-off in their VO2 max than those who continued to ride at higher intensity. But it’s still early days in terms of understanding the effects of training intensity and volume on older athletes. We are effectively the first generation study!

GhostRider62

Eventually as you get within a few months of STP, you might find you need those four rides to be 90 minutes Z2 to trigger improvements but your plan with one day of tempo/ss should be pretty easy to take, meaning recover and get fitter with low risk of burning out.


Once you have your FTP pretty well estimated, you might consider to track your training stress balance (TSB) with one of the online training packages. I use the free GoldenCheetah. What I have found as I have become more mature aka senior is I need to build up slower to not over do it. I used to be able to handle -50 TSB fairly well. For the past 23 days, my TSB has been between -20 and -40 (with one blip down to -48 after a 200k with 9500 feet of climbing in 95F temps). Normally, I do not let myself go worse than -30 TSB over multiple days. This means my training load builds up slowly. YMMV. Although my morning heart rate variability is still good, I am on the edge but only have 5 weeks to my big event of the year and thus, this week's training is pretty much my last real training. I've also found for myself that a long ride (over 4 hours) isn't needed every single week. Every 2-3 weeks seems to be fine but it has to be long enough to matter and as fitness increases, the duration needed to stimulate improvement will increase too. So, I get to the point a 6 hour ride is needed but not every week if that makes sense. Again. YMMV. (I had two ice hockey games last week with the young college kids and played center on one game, and estimating that training load isn't easy).

Highcad

But on the bright side, you're most likely faster and have a stronger cardio system then 99.9% of the population.

ofajen

I wouldn’t assume that first statement is true. I suppose it may be, but check out the second Andy Coggan interview on Inside Exercise where Coggan disputes that specifically, citing experiments where lactate was clamped (held at a high level) during moderate exertion and the primary marker for lipolysis not only didn’t decline but went slightly higher.

So I think that is a point that would have to have some real evidence not contradicted by this line of research. Coggan says we don’t need to burn fat to train our bodies to burn fat and that other modes also trigger and increase that capacity.

Overall, I’d say I’m unlikely to assume any assertion in the exercise research realm is true without a considerable body of evidence.

Otto

MoAlpha

I think you’re right and I hadn’t heard about the lactate clamp experiment when I wrote that. I think that is pretty convincing as far as the real world of training is concerned. However, I believe there is some evidence that lactate is a signaling molecule in the control of lypolysis, which is where that idea comes from.

ofajen

I’m no expert, but my understanding is that the ratio of fat use goes down as blood lactate levels increase, so that would make sense.

I’m enjoying that podcast. As someone who isn’t training for an event, I don’t need to sweat the details too much. OTOH, I enjoy having more understanding of what the scientists have to say based on what experiments show and where some of the things other people talk about are coming from.

Otto

MoAlpha

Yeah, I’m no expert either and I’m just training to hang with a bunch of other old people, but I have the medical letters after my name and have spent a career in clinical research, so it’s all pretty easy for me to understand when someone knowledgeable tells me what to read.

Steamer

Exogenously elevating blood lactate is not the same thing as it being elevated naturally by your own body due to an elevated exertion level.

I am no physiologist, but that's what confused me about Coggans 'counterpoint'.

MoAlpha

What do you think is the relevant difference for this discussion? Circulating lactate has to be involved, since the signal has to get from muscle to adipose tissue to control lipolysis.

Steamer

Not sure why you would ask me, since, as I said, I am not a physiologist. But, I do very much know that complex systems are not always well understood by even the experts, and sometimes unnatural conditions created by an experimental setup can lead to distorted findings due to the gaps in the experimenter's knowledge about the exact mechanisms. Testing a more natural, or native, scenario is always better than an artificial or forced one. That was my point.

In looking at Fig. 1 and 2, or perhaps better - Fig. 3, here:
https://www.researchgate.net/publica...it_Individuals

The relationship between blood lactate and fat oxidation is pretty clear, regardless of fitness and how the curves are shifted. These blood lactate levels were produced by exercise, not something artificial, like infusion of lactate.

MoAlpha

I only asked because you seem smart and might know something I don't. I think the explanation usually offered for the inverse association of lactate and fat oxidation is that blood flow to adipose tissue decreases with exercise intensity, but, as you state, complex systems are complex and just because it's true doesn't mean its causative.