Maths Problem

zbluebirdz

Weight: 74 Kg
Average calories burnt per hour (20Km/hr): 500
Calories in 1 Kg: 7700

=====
100% fat burning zone:
Distance to cycle: ( 7700 / 500 ) * 20 = 308 Km.
Time: ( 7700 / 500 ) = 15.4 hours

50% fat burning zone:
Distance to cycle: ( ( 7700 / 500 ) * 20 ) * 2 = 616 Km.
Time: ( 7700 / 500 ) * 2 = 30.8 hours
=====

If your weight is higher, then it'll take you less time/distance to burn off 1 Kg. However, the lighter you become, it takes more time/distance to burn off the next 1 Kg ...


So, for the OP, it'll take you approximately 600 Km to burn off 1 Kg of fat.

How far is 600 Km? A round trip from Dublin to Tralee and back.


NB: I'm no expert on this topic/subject matter.

petethedrummer

Information Thus Far:
Target bodyfat Loss: 1 Kg
Age: 35 years
Height: 179 cm
Weight: 74 kg
Fat Burn Zone: 111-130bpm (estimated)
Speed (at Zone: 20km/h (estimated)
Basal Metabolic Rate: 1,689 - 2084 cal/day (estimated)
Energy per hour (not exercising): 70.375 - 86.83 cal/hr
Energy per hour (Zone + BMR): 500 cal/hr
Energy per hour (Zone exercise alone): 413.17 - 429.625 cal/hr
Energy per hour from fat (Zone exercise alone 75% fat burning): 309.8775 - 322.215 cal/hr
Time to burn 7700 cal of Fat: 23.9-24.9hrs
Target distance in Zone: 477.94 - 496.97km


Being pessimistic I have to eat 1,689 calories per day and travel 496.97km
Being optimistic I have to eat 2084 calories per day and travel 477.94kms

I'll need to do further reading to confirm the numbers above. and to check my logic. which I'm pretty sure is wrong.

petethedrummer

zbluebirdz wrote: »

If your weight is higher, then it'll take you less time/distance to burn off 1 Kg. However, the lighter you become, it takes more time/distance to burn off the next 1 Kg ...

I'll confirm this later with maths.

Ole Rodrigo

petethedrummer wrote: »

I'll confirm this later with maths.

' You won't find an equation to pedal up a hill '

- old chinese saying

NeedMoreGears

@pete

You're confused? I'm confused.

I also cannot type.

771w = 771 joules per second. There are 4.182kcal in a kj (When people talk about calories, they actually mean kilocalories). Hence dividing by 771 by 4.182 and then by 1000 gives 0.184 kcal/sec (sorry not 0.84). Hence 663 kcal/hr. i.e 22kcal per km or so.

If 35% of this energy comes from stored body fat then you burn 232 kcal of fat doing the 30km. Hence for a full kilo (i.e. 7700kcal worth) you need to travel the 995km. i.e. you only burn around 7.75 grammes of fat per km at that speed (232/30)

The other energy should come from more immediately available energy sources (glycogen??) stored in your muscles. The bit I don't fully (actually not even a tiny bit) understand is how glycogen is replaced if say you don't eat enough calories to replace those you consumed on the bike.

Anyway if I were you I'd go for broke. Aim for 2.5kg which is 2487km ; that gets you to Rome with 20k to spare. You'll have earned that post ride espresso.

smacl

Just a thought that came to me on the bike yesterday, but does one burn a considerably larger amount of energy exercising in colder conditions? Seemed to me that as much energy was being burnt keeping warm as going forward. No idea how this pans out in your equations.

I'd suggest you need to calibrate your model based on putting the kms into the road, stabilizing and diet, and measuring changes in weight / fat mass. Anything other than dead flat, and energy burnt climbing hills will vary based on weight, and wind and weather will also play their part. To me, it seems like there are too many unaccounted for variables in play for your mathematical model to be reliable unless tested and adjusted accordingly.

petethedrummer

My heart rate will be in the fat burning zone. Rendering all other variables moot.

smacl

petethedrummer wrote: »

My heart rate will be in the fat burning zone. Rendering all other variables moot.

Fair enough, but then the result you're looking for is number of hours training at a given HR. This might bear little relation to actual distance covered which would require that the calories are being burnt at a rate proportional to distance traveled, which could hold true indoors on the turbo, but less so in varied terrain and weather.

petethedrummer

We'll assume its a nice day and I'm taking a flat route and there's no wind.

Hours will do if it becomes to complex to translate to distance.

smacl

petethedrummer wrote: »

We'll assume its a nice day and I'm taking a flat route and there's no wind.

Sounds like paradise...

https://www.youtube.com/watch?v=Wrh4r2JJBxA

bambergbike

niceonetom wrote: »

Has anyone ever actually gotten leaner from low intensity exercise like this? I mean weight loss preferentially from fat without also losing muscle etc? I never have and I haven't noticed it in others. Maybe for very heavy people who are starting from such a low level of fitness that any exercise would have that impact. The leanest athletes I see tend to be the ones that do lots of very explosive/anaerobic stuff...

Yes, me. Not lean by any means, but leaner. I changed my diet, but definitely also knocked off a few extra kg here and there by doing a long slow weekend rides without much fuel as base miles in Spring 2012. I kept them flat and didn't force the pace so I wouldn't suddenly lose power on a big hill miles from home. If you can chug along without feeling an urgent need to refuel, you're teaching your body to run on fat. If you ride harder, you might be burning more fat in absolute terms, but you'll also exhaust your carb stores and end up having to take on lots of fuel to get home or to recover once you get there.

It's true that I was pretty heavy in Spring 2012 the time; I'm curious as to whether the same strategy would work now again that I'm a little lighter. I don't think it's a year-round strategy. In fact, I had sort of intended to rinse and repeat in spring 2013 and in the end I never bothered, I just hit the hills immediately as soon as the winter snow melted. By the time the snow melted I think it was practically summer and a bit late to start riding leisurely, boring base miles.

My improved capacity for fat burning doesn't just make it easier for me to use stored body fat as fuel - it also makes it easier for me to use fat as a fuel source, full stop. A few years ago, I would have felt downright ill if I had stopped in the middle of a hard ride and eaten fish and chips, or a sausage, or cheesecake, or lots of ice-cream. But my stomach no longer discrimates between fat and carbs, it accepts absolutely any old rubbish now. Not sure it really should, but it does.

ROK ON

Tom

The question you raise whether any fat person has succeeded with low intensity exercise is fascinating.

Before being fat I was very very fat. I hadn't exercised in years.
Loved cycling so got back on the bike.

Weight fell off.

Was it low intensity - not sure. To someone weight over 18stone who had a decade of heavy partying dri king eating and debauchery with no exercise then there is no such think ad low intensity exercise. It's all hard - your HR is through the roof because you have no aerobic fitness whatsoever.

8 years later I am five stone lighter and merely fat. I know can do low intensity exercise because I have a level of fitness. Also I can do high intensity stuff and go fast. Before high intensity was simply getting on the bike and hoping not to get a heart attack.

I no longer believe in low intensity stuff.

I will do a few A4 races and then my club league. My training regime for the upcoming winter is:
Fours hours per week max - four 1 hour sessions.
Mostly zone 3. Starting with 1 hour per week at z4 with 5 minutes of HIIT.
Over 16 weeks I want to bring that to 3 hours of intensity.

Gradually building each week and testing for milestones (ie lthr with a set turbo drill and TTs over 5 to 30 minutes).

No science behind this. I just thought that with a limited time to train that this makes sense. Also the fittest I was ever was the winter it snowed badly. That year training was 2 turbo sessions and 2 ScottMcDonald spinning classes per week with no long rides and some hiking in the snow.

Long rides and base training for short races are IMHO nonsense.

Ducks for cover and retreats.

petethedrummer

According to this article. The calorie content on food could be wrong by up to 39% so I'm going to have to revise down the amount of food I can eat. Just to be sure. Not leaving anything to chance.
http://www.motherjones.com/environment/2013/02/calorie-count-inaccurate-microbiome-cooking-processed

New calculations to follow.