Cycling UK Forum

David2504 wrote: ↑11 Jul 2022, 7:40pmBut that could happen to anyone at anytime not necessarily involving cycling or any strenuous physical activity. Could happen driving to the shops, walking the dog, going to the pub.

I think this is an important point. Assume someone who enjoys cycling, so does it a significant amount, and has not overtrained, but has an underlying heart condition for whatever reason, such as heredity or plain bad luck. All things being equal, since that person spends a significant amount of time cycling, there's a significant chance that, when an incident happens, it will be during a bike ride. But the cause still won't have anything to do with cycling.

This is very real for me. I had a double bypass four years ago. I was cycling when I noticed an issue and, a few hours later, I was wired up to loads of machines and being lined up for theatre. But I was cycling back from an AGM and definitely not over-exerting myself. Nor had I been overtraining - I've always regarded training as a mild form of cheating. I just use a bike for transport, ride Audax events up to 200km, do the odd club time trial for fun, and (lately) use Zwift a couple of times a week. It's pretty clear that my lifetime of cycling made for a far better outcome than might otherwise have been the case, just as it's clear that my cycling had nothing to do with my incident. The consultant who discharged me was happy for me to go back to pushing myself as much as I liked. The last thing I need to do is avoid cycling just in case - that could be quite dangerous!

The massively overwhelming majority of people (me included) need to do more cycling, not less, from a health perspective. I would suggest that most of the tiny percentage of keen sports cyclists who actually need to do less will probably be found on cycling fora other than this one.

re_cycler wrote: ↑14 Apr 2023, 8:05amI wonder if a better question would be how long does my body need to recover from the stress induced by recent exercise (along with any other stress factors in my life).

Overtraining is caused by the accumulation of excessive fatigue, which is not necessarily the result of a large volume of exercise.

Training correctly entails pushing yourself a little beyond your current level of fitness, during which microscopic 'damage' to the muscle fibres occurs, and then resting, during which time the damage is repaired to a better standard than it was previously. It's this improvement which constitutes an increase in fitness as the cycle is repeated again and again, but the whole process rests on the supposition that you don't cause too much damage in one go, and allow sufficient rest for complete recovery.

However, if you do too much damage and/or don't rest enough afterwards, then the next session will add to it, and if you keep repeating that process you descend into chronic fatigue instead of getting fitter. That's fine if you recognise the problem and stop for a good rest, you can then restart and get it right next time, but if you keep going, and accumulate a sufficiently high level of fatigue, and maintain it for long enough, the damage can become permanent, and unrecoverable. That's what overtraining syndrome is.

People say "Oh, only athletes get overtraining syndrome", but they're the ones motivated to do most exercise. If you take a couch potato and an athlete, put them on bikes and have them go on a ride, side by side, same speed same distance, who's going to come back most fatigued? And if they keep repeating it, who's going to become overtrained? It's not the athlete is it. The point here is that if an untrained, unfit amateur is overenthusiastic and highly motivated, he can easily rack up a large amount of fatigue completely unaware of what he's doing, especially if he hasn't been given any competent coaching.

Forty three years ago that person was me, and unfortunately whenever I mentioned anything, the advice I got was always to get more exercise. So that's what I did, the worse I felt, and the more my performance declined, the harder I would exercise in the belief that if only I could do enough I could get fit. Every exercise session had to be a personal best, faster or further than the last, and overtraining produces implausibly (and unsustainably) large improvements at first.

What interests me is that Calvo et al have found that once you control for exercise hours, athletes are less likely to get AF than non-athletes, and I think that might well be because athletes have access to proper coaching, and will be less likely to overtrain. It's also interesting that the association between exercise hours and AF is stronger than the association between aerobic fitness and AF, which might also be showing that the root cause of AF risk is overtraining rather than fitness or exercise hours.

It's not your absolute exercise volume that matters, it's your exercise volume relative to your own level of fitness, because that's what determines whether you get fatigued or not. Don't advise people who may be less fit than you are to do the same level of exercise that you are just because it works for you. And if your performance doesn't improve when you increase your training load, it's because you're doing too much.

Nearholmer wrote: ↑14 Apr 2023, 5:25pm Had a read of the article, and the authors do indeed conclude that, despite efforts to account for as many as feasible, confounding factors associated with the socio-economic groups most likely to be involved in physically demanding work may be at play, smoking, diet etc. They suggest other possible causes too though, not just this one.

Having pondered it a bit further though, I do think that there might be a difference between “work exercise” and “leisure exercise”, in that the former tends to be unremitting, often semi-repetitious, and often at all sorts of hours of the day, and if outdoors then in all sorts of weather. People cog on with back pain until it completely puts them out of action, likewise other I troubles. Only the most obsessive leisure exerciser would put themselves through the same.

From Garcia et al on the subject:

"...differing methods used in previous meta-analyses limit comparability of relative risks across different outcomes. The only initiative to consistently consider the population impact across diseases (five in total) is the Global Burden of Disease (GBD) study, which uses estimates of total PA, including occupational activity. This is problematic as occupational activity is generally poorly measured compared with non-occupational activity and estimates of activity at work often dwarf the non-occupational component. One reason for this is the use of gross metabolic equivalent of task (MET)-hour/week to quantify PA volume. Sedentary office work may be considered to cost approximately 1.25 METs, of which 1 MET represents resting metabolic rate. Non-occupational activity is typically more intense (eg, walking at 4.0 km/ hour is approximately 3 METs), meaning the relative contribution of the resting metabolic rate is smaller. Including low-intensity high-duration activities such as occupational activity without marginalising the resting component can therefore distort the PA exposure dramatically. Furthermore, even when occupational PA is well measured, it remains unclear whether it has similar health benefits to non-occupational activity. These factors add statistical noise, decreasing the accuracy of the estimated associations, and may underestimate the contribution of non-occupational PA."

Not much recognition of difference between occupations there.

axel_knutt wrote: ↑15 Apr 2023, 6:06pm It's not your absolute exercise volume that matters, it's your exercise volume relative to your own level of fitness, because that's what determines whether you get fatigued or not. Don't advise people who may be less fit than you are to do the same level of exercise that you are just because it works for you. And if your performance doesn't improve when you increase your training load, it's because you're doing too much.

Completely agree, although I would also include other stressors such as lack of sleep or stressful life situations. They're all adding to those fight or flight responses which I believe feeds into increased Cortisol levels on top of the micro muscle damage.

I have no idea how stamina works at a physiological level, but it strikes me that measured fitness, and stamina may be different things, or at least not completely the same thing.

The battery analogy does seem to work in respect of stamina, in that some people have a bigger battery than others, activity depletes “charge” at different rates, with very intense activity burning through “charge” at a grossly disproportionate rate, and a poor recharging regime (diet, hydration, rest, sleep) damages not only short-term capacity, but long-term capacity.

Back to the “work exercise” thing: I do wonder whether it damages some people because they push on at low states of charge, and gradually deplete their stamina, rather like using a set of cells that aren’t managed properly, whereas ordinary (not madly obsessive) “leisure exercise” tends to go with managing lifestyle, and hence “charging regime” carefully.

a.twiddler wrote: ↑13 Apr 2023, 9:29pm
The spirit might be willing but the flesh is decidedly weak,

I think it is the other way round. One of my complaints to the long-suffering Mrs H is that on no occasion do I get any encouragement to cycle. In all my social and work activities, cycling is a non-starter and I'm always the only one to get there by bike. Venues are selected with no indication of their cycle-accessibility or distance and no-one else thinks of turning up on a bike. They aren't all 85 year-old invalids and could easily do more. Society is now built around the car and other labour saving devices. The spirit is decidedly unwilling and the flesh is only getting weaker.

It's not your absolute exercise volume that matters, it's your exercise volume relative to your own level of fitness, because that's what determines whether you get fatigued or not. Don't advise people who may be less fit than you are to do the same level of exercise that you are just because it works for you. And if your performance doesn't improve when you increase your training load, it's because you're doing too much.

I’ve been reading axel nuts’s comments with interest, experiences to understand and to learn from.

It seems to me that overdoing things can take multiple forms one of which might just be a never can be repeated (ie.terminal) excess; in athletic terms it might not (relative to the activities of others) be much of an excess, it’s simply more of a peak load than that person’s body could sustain at that time. Of those excesses there are at least two forms: one in which an underlying weakness isn’t known and the other in which we simply push ourselves far too hard - probably ignoring or dismissing any warning signs on the way.

The massively overwhelming majority of people (me included) need to do more cycling, not less, from a health perspective. I would suggest that most of the tiny percentage of keen sports cyclists who actually need to do less will probably be found on cycling fora other than this one.

Credit, drossall.

I wouldn’t want to argue about that but really it’s well outside of my intended comment as OP. The idea is to avoid overdoing things so that you remain in a fit state to continue to do things. Of course, if someone takes no exercise at all then the outcome of too sedentary a lifestyle is well known too … It’s a case of seeking that which is likely to have a good outcome and avoiding that which is not.

To my mind we can learn from the reported experiences of others, and I can’t see that it particularly matters whether they are members of this forum or not.

re_cycler wrote: ↑16 Apr 2023, 10:43am

axel_knutt wrote: ↑15 Apr 2023, 6:06pm It's not your absolute exercise volume that matters, it's your exercise volume relative to your own level of fitness, because that's what determines whether you get fatigued or not. Don't advise people who may be less fit than you are to do the same level of exercise that you are just because it works for you. And if your performance doesn't improve when you increase your training load, it's because you're doing too much.

Completely agree, although I would also include other stressors such as lack of sleep or stressful life situations. They're all adding to those fight or flight responses which I believe feeds into increased Cortisol levels on top of the micro muscle damage.

Sleep has a huge impact on cardiovascular health. Pro teams take this very seriously. Bad sleep has a detrimental impact on heart rate variability. If I have a very bad night sleeping my HRV can drop as much as if I'd done a massive effort the day before. Modern professional athletes suffer from less AF than amateurs now. We know amateurs push themselves for a higher percentage of their ride time than pros. Cardiologists believe this may the reason pros have less arrhythmias. Interestingly (to me) I've found by having more 'easy' rides and recovery days my performance improves.

softlips wrote: ↑17 Apr 2023, 9:34am ...
Modern professional athletes suffer from less AF than amateurs now.
...

Do you have a source for that, please?

Thanks

Jonathan

I've found by having more 'easy' rides and recovery days my performance improves.

There is a lot in this.

I have a tendency to unwittingly spend too much time above 85%HR during rides, especially off-road in the winter ….. I get caught-up in the fun/challenge of it, and only afterwards realise I’ve done it. Then feel weary the next day.

Right now, I’m having yet another attempt to re-train myself to make rides ‘easier’, very consciously controlling HR down. I think of it as “going into touring mode” even on half-day rides, and it works very well …….. so quite why I’m constantly slipping back into the other habit, I’m not sure!

drossall wrote: ↑15 Apr 2023, 4:29pmI would suggest that most of the tiny percentage of keen sports cyclists who actually need to do less will probably be found on cycling fora other than this one.

Keen sports cyclists, amateur athletes if you like, are likely to be well clued up on how to train properly, and probably have the advice of a coach, the people I see as most at risk are leisure cyclists who are overenthusiastic but not competitive. I wasn't competitive with others because I knew I'd never win, so I used to compete against myself and chase a personal best every time I got on the bike. At first the gold medals come thick and fast, but they soon run out and then you just end up running yourself ragged chasing your own shadow, a bit like the gambler trying to win his money back.

Matos et al found that the prevalence of OTS was higher with low intensity, solitary sports, (eg: golf) and low time spent in alternative activities. There was a significant association with more hours per day and more days per week, and solitary sport was itself associated with more training and less hobby time. “Our data therefore provide new evidence that OT is an issue not just seen in elite athletes”

re_cycler wrote: ↑16 Apr 2023, 10:43amI would also include other stressors such as lack of sleep or stressful life situations.

Nutrition is another.

Kreider et al think that acute or chronic carb depletion may play a role in the onset of OTS. Increasing fat intake inhibits carb utilisation and accelerates the onset of exhaustion: subjects can run 70% longer before exhaustion on a high carb diet compared with high fat.
The extent of protein degradation during exercise is heavily influenced by the availability of bodily carbohydrate stores. Overtrained swimmers were found to have not consumed enough carbs.

I've noticed people on here singing the praises of low carb diets.

softlips wrote: ↑17 Apr 2023, 9:34amWe know amateurs push themselves for a higher percentage of their ride time than pros.

That doesn't surprise me.

Jdsk wrote: ↑17 Apr 2023, 9:37am

softlips wrote: ↑17 Apr 2023, 9:34am ...
Modern professional athletes suffer from less AF than amateurs now.
...

Do you have a source for that, please?

Thanks

Jonathan

I'm pretty sure it was in one of Dr Gemma Parry-Williams papers.

softlips wrote: ↑22 Apr 2023, 7:44am

Jdsk wrote: ↑17 Apr 2023, 9:37am

softlips wrote: ↑17 Apr 2023, 9:34am ...
Modern professional athletes suffer from less AF than amateurs now.
...

Do you have a source for that, please?

I'm pretty sure it was in one of Dr Gemma Parry-Williams papers.

Thanks.

I couldn't find that.

Here's the 2021 systematic review:

"Risk of atrial fibrillation in athletes: a systematic review and meta-analysis":
http://dx.doi.org/10.1136/bjsports-2021-103994

Jonathan

axel_knutt wrote: ↑20 Apr 2023, 10:06pm
Nutrition is another.

Kreider et al think that acute or chronic carb depletion may play a role in the onset of OTS. Increasing fat intake inhibits carb utilisation and accelerates the onset of exhaustion: subjects can run 70% longer before exhaustion on a high carb diet compared with high fat.
The extent of protein degradation during exercise is heavily influenced by the availability of bodily carbohydrate stores. Overtrained swimmers were found to have not consumed enough carbs.

Most of this type of study ( The current Amazon price for that hardback is £193 ! ) tends to use athletes who aren't used to be low carb diets and then just looks to reduce their carb intake, you would like to think that the calorie intake is kept the same. From what I understand it can take weeks for the body to adjust to a state of burning fat efficiently. As yet I haven't come across any studies where they've monitored athletes who already compete in a state of ketosis.
All of which is just an observation of the research not a recommendation for any type of diet or style of eating

As GCN found out, the heart experts said active people live longer than inactive ones. So I go as hard as I feel like. Living on the edge!!!!!!