Weight / Fat loss

I think it got popular when 200kg lumps (looks in mirror) wanted to beat the bulge and started heading to gyms. Doing proper exercise was too hard so when someone said "oh, look you burn a higher % of fat if you just walk to 60% HRmax" they were all like woo hoo and all the fat burning zone books appeared.

looks in mirror

Mirrors, surely?

https://gizmodo.com/5929711/the-largest-mirror-in-the-world-is-also-one-of-the-most-beautiful-places-on-earth

”fuel your workout with fuel on your body - fat where possible”

“At what intensity?”

Sorry - should have been specific that I was referring to workouts with an intensity at zone 2. But I understand the following comments with regard to high intensity workouts fueled.

Doing proper exercise was too hard so when someone said "oh, look you burn a higher % of fat if you just walk to 60% HRmax" they were all like woo hoo and all the fat burning zone books appeared.

"burn a higher % of fat" was the big bit they all misunderstood and ran off in the wrong direction with, e.g. if (made up numbers) at:-

• lower intensity you burn 100kcal/hr from fat and 100kcal/hr from carbs
  
• a higher intensity you burn 120kcal/hr from fat and 130kcal/hr from carbs
  
  

then lower intensity is not "better" just because you get 50% of energy from burning fat compared to 48% at higher intensity. With these made up figures you burn more fat at the higher intensity, not where the best percentage lies.

But if at lower intensity you burn x fat and y carbs and then at a higher intensity you burn the same amount of fat (x) but 1.5y carbs then there's no huge benefit looking at just the session alone (post exercise effects are another matter) since you end up burning the same amount of fat either way.

(Further effects would be that the higher intensity session should improve your overall CV fitness more, barring overtraining, so that you'll probably be even more efficient for future sessions which could lead to more fat burn, etc. It's going to be very complex.)

What would be useful is if someone has done a study to see at what rate fat and carbs are burned at different exercise intensities.

If fat burn increases slightly at higher intensities then all the better to go out and smash it, but if the body starts to burn less fat (and more and more carbs) at higher intensities then smashing it might not be so beneficial.

No idea how they'd actually measure that though, probably #magnets

What would be useful is if someone has done a study to see at what rate fat and carbs are burned at different exercise intensities.

I'm sure I've seen graphs of that. Gas masks...

I can't find the one I'm thinking of, it's a bar chart

I prefer performance 'over weight'...
http://science.sciencemag.org/content/362/6416/781

I'd need to see the data behind that graph as just the relative comparison doesn't tell anyone if the number of calories obtained from burning fat is staying the same, increasing or decreasing as intensity increases.

Going back to my made up figures:-

• lower intensity you burn 100kcal/hr from fat and 100kcal/hr from carbs
  
• a higher intensity you burn 120kcal/hr from fat and 130kcal/hr from carbs
  
  

Those numbers give a decrease in the relative contribution from fat, but an actual increase in absolute contribution from fat.

even with all this science - training harder is still training harder ...
My hypothesis is - if I can train 3-4 hours in zone 2 without eating, the resulting calorie deficit is greater than it would be if I did a one and a half hour high int pass fuelled with carbs. Works for me in the winter so my lsd passes give me greater cal deficit than fueled high int passes (or even better non fueled high int passes).
I dont know - read some bullshit about how Wiggo lost weight when he went from track to road and I bought it straight out... you know distance passes after an espresso = marginal gains

I’d also add that finding what works for you is really the most important thing. The science of what intensity is optimum is one thing, but it’s kind of irrelevant as what works best for each individual is likely to different.
We all know what we should be doing with our diets and training, but that’s not always what we actually do. And that’s why I prefer the realistic solution over the “optimum” one - and that will be different for everyone.

Tried to start the new year with a bit of a fitness bang and fucked my knee in a ride. So frustrating. Calorie deficit is so much harder with no cycling/running and getting the bus.
Christmas damage & progress:

I will see 70kg in 2019.

The ratio moves towards higher CHO use at higher intensity.

I don't get what you're trying to work out?

"It is well-established that whole body fat oxidation increases with exercise intensity up to ~55-65% of VO2max, but decreases at higher exercise intensity [1, 22]. Why fat oxidation decreases at high exercise intensities is not completely understood, but evidence suggests a decrease in FFA availability due to a decrease in blood flow to adipose tissue, a limited capacity per unit time to generate ATP from oxidation of plasma FFA, or a decrease in the activity of CPT1 [1]. The exercise intensity at which maximal fat oxidation rates occur varies according to training status, sex, and mode of exercise. Maximal fat oxidation rates (~05.-0.6 vs. ~0.4-0.5 mg · kg−1 · min) and the intensities at which this occurs (59% - 64% vs. 47-52% of maximal oxygen consumption (VO2max)) are higher in highly trained vs. moderately trained individuals. Maximal fat oxidation rates appear to be higher in women compared to men; fat oxidation rates are higher at a given exercise intensity in females, and occurs at a higher exercise intensity. Although the mechanism is not clear, the ability of females to utilize more fat during exercise may be due to differences in levels of circulating hormones and catecholamines, a more oxidative muscle fiber type distribution, an increased sensitivity to catechomlamine stimulated lipolysis, or increased activity of hormone-sensitive lipase [1]. Maximal fat oxidation rates also appear to be higher during walking and running compared to cycling, which may reflect recruitment of a smaller muscle mess and a lower catecholamine response during cycling [1]."

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2885974/

https://www.ncbi.nlm.nih.gov/core/lw/2.0/html/tileshop_pmc/tileshop_pmc_inline.html?title=Click%20on%20image%20to%20zoom&p=PMC3&id=2885974_nihms-211189-f0001.jpg

Absolute (A and B) and relative (C and D) 24-h carbohydrate (Carb) and fat oxidation in men (M; gray bars) and women (F; open bars). Values are means ± SE; nos. within bars are means. Con, no-exercise day; LI, low-intensity aerobic exercise day; HI, high-intensity aerobic exercise day; FFM, fat-free mass. (P > 0.05).

f I can train 3-4 hours in zone 2 without eating

You'd train harder taking on fuel and burn more calories in the same time.

They did similar experiment in one of those post-xmas diet shows on TV this week, showing a couple of runners, lasting longer with fuel so using more calories (even with the extra taken on). If you can do 3-4 fasted, day to day and not carve holes in your kitchen looking for food, good on you. I'd decimate the local shops...

I don't get what you're trying to work out?

The following (thanks for the links) answers my queries:-

"It is well-established that whole body fat oxidation increases with exercise intensity up to ~55-65% of VO2max, but decreases at higher exercise intensity [1, 22].

So if you go above that magic 55-65% of VO2max range then your body starts to burn less and less fat. You can see why the 'fat burning zone' became popular because they took this single fact in isolation and didn't consider the wider picture, especially...

Why fat oxidation decreases at high exercise intensities is not completely understood...

Along with why stuff like HIT alone seems to work for fat loss (as shown by the Michael Mosely documentaries) despite it being contrary to the points above.

Pearoast? https://www.theguardian.com/society/2019/jan/05/truth-obesity-five-fat-myths-debunked

4kg down since lamb day...

The point is, if you have 3-4hrs of ride time, then doing that time harder because you can, because you're fueling it, means you'll burn more calories than if you did 3-4 hours of unfueled riding. Exactly what the differences would be depend on the individual and state of training.
There's a whole heap of other stuff like - recovery, muscle damage and the ability to do back to back training days at the same intensities, problems with long-term energy imbalance like RED-S, properly fueled rides are less likely to result in URT infections. Riding fasted now and then has benefits but I wouldn't create a whole program around long fasted rides.

Wiggo just nailed a fuck load of catabolic asthma meds. Insta weight loss.

Re-embarking on some tracked low calorie intake weight loss, because I'm useless at portion management, want to drop 20kg for good and I don't want to take years doing it. Yay.

Aiming for 1400-1500 kcal pre-exercise. Is there any non-pseudo science regarding appropriate protein intake to prevent too much muscle loss? I'm still cycling to work every day, climbing once or twice a week and the odd mtb ride here and there. Not eating much meat and dairy, if at all, and boring food can fuck off. Which might make life a bit harder. Any advice?

~25g per intake/meal

2.2 grams per kg if you are cutting really hard, tried and tested by starving bodybuilders everywhere.

However...they are also very very lean already. If you are already unhappy with food choices, then going lower may be better. The best diet is the one you can stick to.

I find these discussions on fat loss all interesting, but I am simply incapable to worry about this as whenever I diet high intensity and loads of reps simply won't happen.

So I walk / cycle to work as fast as I can which is not as fast as loaded with coffee and full Ulster fry... and do fewer reps / do more rest but keep the weight on the bar high.

I eat 1, maybe 1.5 meals per day. Is that the maximum you can absorb in one go or something?

I think I'm managing about 0.4 g/kg on average...

Basically yeah.

1-1.5 meals a day? Fuck that.

I'd rather fuel for health and performance than weight loss. Being lighter would be a bonus but I'd rather be strong, healthy and trick people into thinking I'm smart or at least awake.

2.2g/kg/day is pretty high. Muscle protein synth tapers off around 25g per meal (every ~3rs) so I'd have to be snacking like crazy to hit 2.2/g/kg/day. I'll stick with the sports science version of 1.6/g/kg/day which for me is about 6 x 24g protein hits per day, much more reasonable. Not that I'm anywhere near that normally.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3705323/