Recommendation for dealing with long distance cycling in calorie counting.
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It seems to me that Garmin is using more than just average speed. I think they are also including elevation gain. That doesn't account for wind, but it would provide an accurate number if the wind is calm.0
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All of the conversation about the accuracy of calorie calculations from exercise aside, the real question here in my mind is how does one absorb into a calorie restricted diet very large energy burns. Again without getting into what it takes to create a negative net calorie count for the day, let's all basically agree that it's possible.
OK, no we are on solid ground. Using me as an example; I'm a 215 pound 53 year old guy with a calorie goal of 1600 a day. On a typical 2-3 hour 30+ mile mtn bike ride with 2500-3000 ft of elevation gain, including eating 3-4 shot blocks and a cliff bar during the ride, I believe that I could easily find myself in negative territory for the day. Again, without getting into how many calories from which flavor cliff bar, etc... let just agree that it's not unlikely that under these conditions I'd be negative for calorie count for the day.
So, the question becomes what's a good rule of thumb for eating back into the positive?
I'm going to toss out there that the two extremes of the spectrum probably are off limits, which would be do nothing, stick to your 1600 consumed calorie goal and at the other end eat back all your exercise burn to reach your net calorie goal of 1600. Those are the easy parts of the rule, there's a lot of room in between.
Thoughts?0 -
That calorie burn seems way too high. I read recently that ~300 calories per 10 miles is a useful average, which would put you at a little over half of what your cyclo computer estimated. I wonder if it reported total calories instead of active calories. That seems to be the case with some devices.0
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caloriemuse wrote: »All of the conversation about the accuracy of calorie calculations from exercise aside, the real question here in my mind is how does one absorb into a calorie restricted diet very large energy burns. Again without getting into what it takes to create a negative net calorie count for the day, let's all basically agree that it's possible.
OK, no we are on solid ground. Using me as an example; I'm a 215 pound 53 year old guy with a calorie goal of 1600 a day. On a typical 2-3 hour 30+ mile mtn bike ride with 2500-3000 ft of elevation gain, including eating 3-4 shot blocks and a cliff bar during the ride, I believe that I could easily find myself in negative territory for the day. Again, without getting into how many calories from which flavor cliff bar, etc... let just agree that it's not unlikely that under these conditions I'd be negative for calorie count for the day.
So, the question becomes what's a good rule of thumb for eating back into the positive?
I'm going to toss out there that the two extremes of the spectrum probably are off limits, which would be do nothing, stick to your 1600 consumed calorie goal and at the other end eat back all your exercise burn to reach your net calorie goal of 1600. Those are the easy parts of the rule, there's a lot of room in between.
Thoughts?
recommendation is to eat back roughly 50-75% of your workout calories - MFP is based on the idea of eating back workout calories (in general)0 -
Jthanmyfitnesspal wrote: »However: To get your calorie burn from your energy expenditure, you need to know your efficiency factor, which I see from one article is about 24%. That means you (or your software) takes the measured energy you applied to the cranks and multiplies it by ~4.17 to get your calorie usage. How universal and constant is this factor? It could change with your level of fitness, age, weight, or sex
I'm in the garden using my phone to post, so I don't have any links handy. But all the research has shown that there's almost no variation between different people on a road bike. It's a pretty constrained environment, it's not like running where your vertical oscillation and gait and everything else effect your economy. We're just turning the cranks in a circle.0 -
caloriemuse wrote: »So, the question becomes what's a good rule of thumb for eating back into the positive?
I'm going to toss out there that the two extremes of the spectrum probably are off limits, which would be do nothing, stick to your 1600 consumed calorie goal and at the other end eat back all your exercise burn to reach your net calorie goal of 1600. Those are the easy parts of the rule, there's a lot of room in between.
Thoughts?
To expand on my earlier remarks: In the 1546 days that I've been tracking my food and exercise calories, I've had 50 days where my net calorie estimate was under 1000. On three of those days, it was negative; those were days when I had done particularly long or demanding rides (e.g., a 111-mile ride in the Berkshires with 9,000 feet of climbing). The other days involved mostly long rides (40+ miles) or long runs (10+ miles).
My approach to "eating back into the positive" has been twofold. I'll eat a lot on the day of the event itself: I have a larger than usual breakfast, and aim to eat and drink 200-250 calories an hour during the event, which is around the maximum that a typical athlete can absorb during moderate to intense activity. I'll also have a calorie-rich meal after the event. I can eat quite a lot: my record was an estimated 4,011 calories, on a day when I did a 90-mile ride that expended an estimated 3,017 calories.
But usually I know that I'm going to do something like that well in advance, and a few days beforehand I'll start to eat a couple hundred calories over my goal. If necessary, I'll also eat over my goal for a few days afterwards. For me, eating more is one of the features of endurance cycling! The main reason is that I enjoy the ride, of course, but the food is a nice extra.1 -
I believe Garmin connect uses just under 25% general efficiency factor (haven't checked since I started using it about 1.5 years ago) which is typical for most people. General range is around 23%-27%, and 25% is used for quick conversion from kj to kcal. Elite cyclist are around 23% range, see https://sportsscientists.com/2010/07/cycling-performance-what-is-possible/.
#1 - Checkout ipbike. The virtual power estimate is ok for flat and no wind. Don't know other apps but suspects same limitation. Without additional sensors, your guessing at the coefficient of drag and wind speed. Not sure why but VP is way off on climbs.
#2 - HRM can be as accurate as MET. Good luck pushing the HR accuracy past 60-90 minutes and for HR ranges over 80ish%/below 60ish% of max HR.
#3 - A watt is a watt. Your threshold power will be the limiter. On climbs power to weight is king, on flats absolute wattage and aerodynamic is king. Power is direct measure of work done so don't see a need to pin down a correlation based sex and age.1 -
A couple of the reasons I have trouble using my heart rate to calculate calories are:
1) My heart rate spikes just before a big climb. I get nervous and it goes up. Then I start the climb and relax and my HR goes down. But while I'm on the flat, just before the climb, when my HR goes up, I'm not actually expending a lot of energy. I start expending the energy when I start to climb, when my HR settles down.
2) If I'm stressed my HR goes up. Did a 100 km ride on Saturday feeling quite distressed about the bad news in the long distance cycling world we all heard on Friday ... and my average HR was a good 10 bpm higher than usual. Did I expend more energy than usual? Nope. I was just really tense.0 -
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A couple of the reasons I have trouble using my heart rate to calculate calories are:
1) My heart rate spikes just before a big climb. I get nervous and it goes up. Then I start the climb and relax and my HR goes down. But while I'm on the flat, just before the climb, when my HR goes up, I'm not actually expending a lot of energy. I start expending the energy when I start to climb, when my HR settles down.
2) If I'm stressed my HR goes up. Did a 100 km ride on Saturday feeling quite distressed about the bad news in the long distance cycling world we all heard on Friday ... and my average HR was a good 10 bpm higher than usual. Did I expend more energy than usual? Nope. I was just really tense.
Another example ... my HR is consistently about 10 bpm higher when I'm riding in traffic as when I'm riding on an empty country road. The terrain could be the same, the effort could be the same, the speed could be the same, same bicycle and everything ... but traffic gets my HR up.
And if I'm nervous about a ride for some reason ... I rode the first 75 km of a 200 km randonnee with a club I'd never ridden with before, on a route I'd never ridden before, and my HR sat at about 155 bpm the whole first 75 km ... and then I relaxed when I realised it was going to be OK, and my HR suddenly dropped to about 135 bpm.
But yes, it's good to check several different methods and I tend to go with whatever is the lowest.0 -
caloriemuse wrote: »All of the conversation about the accuracy of calorie calculations from exercise aside, the real question here in my mind is how does one absorb into a calorie restricted diet very large energy burns. Again without getting into what it takes to create a negative net calorie count for the day, let's all basically agree that it's possible.
OK, no we are on solid ground. Using me as an example; I'm a 215 pound 53 year old guy with a calorie goal of 1600 a day. On a typical 2-3 hour 30+ mile mtn bike ride with 2500-3000 ft of elevation gain, including eating 3-4 shot blocks and a cliff bar during the ride, I believe that I could easily find myself in negative territory for the day. Again, without getting into how many calories from which flavor cliff bar, etc... let just agree that it's not unlikely that under these conditions I'd be negative for calorie count for the day.
So, the question becomes what's a good rule of thumb for eating back into the positive?
I'm going to toss out there that the two extremes of the spectrum probably are off limits, which would be do nothing, stick to your 1600 consumed calorie goal and at the other end eat back all your exercise burn to reach your net calorie goal of 1600. Those are the easy parts of the rule, there's a lot of room in between.
Thoughts?
I agree concerning the conversation. The accuracy issue is more of a technology issue, but regardless, runners and cyclists are putting in some massive calorie burns and not replacing those calories is dangerous. For a 2-3 hour bike ride, start about thirty minutes before the ride and eat about 30g of carbs. During the ride, eat near (but not more than) 60g of carbs per hour. Then within the thirty minutes after the ride, eat some protein. This would give you near 1,000 calories. The rest of the day, eat at least the 1,600 calories as if you didn't go for a bike ride. That brings you up to 2,600 calories. That would leave you about 1,000 calories unaccounted for. Assuming you have an accurate calorie count, you really should eat those calories and you will probably want to, but since you are trying to lose weight, it isn't as critical that you consume all of your calories as it would be if you have a low body fat percentage and you are trying not to kill yourself with your fitness activities.0 -
MFP cycling estimates do seem to come out very high - at least for road cycling. The 16-20mph band is also ridiculously wide as there's a hell of a difference between 16.1 and 19.9mph!
Once you get to ">20ph racing" they get astronomical.
Don't forget that once you hit about 15mph air resistance becomes an ever-increasing problem that must be overcome just to maintain your speed. Assuming no wind on flat ground the per-minute calorie expenditure for a 160-pound rider is approximately
2.9 at 15mph
3.5 at 16 mph
4.2 at 17 mph
4.9 at 18 mph
5.8 at 19 mph
6.8 at 20 mph
(From Science of Cycling)0 -
Jthanmyfitnesspal wrote: »
Get a lab test to determine your GE and power meter will be more or less spot on. Your GE generally don't change much. Once per year for first three years is probably more than enough from couch to general fitness. Besides for most people using 25% your caloric expenditure is either under reporting or at par. Moving 1% down from that point takes many years of hard work.
For sports other than cycling, I would agree on trying different methods. Given how expensive cycling is, a ~$500 for a power meter (single sided, double that for both sides) is peanuts. That's about my yearly budget for wear and tear (tires, tubs, chains, and, cable and housing). I didn't get it to count calories (that was a bonus) but for training and as a pacing aid.0 -
You don't really need to eat for under 2 hour ride and with saddle time 3 hours is doable if the ride is mostly under 90ish% of functional threshold power. And, I haven't noticed much of a change in appetite (more suppressed than an increase in general).0
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You don't really need to eat for under 2 hour ride and with saddle time 3 hours is doable if the ride is mostly under 90ish% of functional threshold power. And, I haven't noticed much of a change in appetite (more suppressed than an increase in general).
I think that depends on the person, but most of the guidelines I've seen say that you should eat if the ride exceeds 90 minutes. Some even say 60 minutes. For me, 90 minutes at 90% FTP would be 1,350 calories, which is just under the 1,400 - 2,000 calories of glycogen that is stored in the muscles. While that means I'm not in danger at that point, the reality is that I can't guarantee that a ride will stay under 90 minutes or that I won't push beyond 90% FTP. By the time I can answer that question with any certainty, I need to have already been eating.0 -
Jthanmyfitnesspal wrote: »
With a power meter, you'll never be more than 5 % off from the gods' honest truth. I'd say 95 % or better accuracy is pretty good.0 -
You don't really need to eat for under 2 hour ride and with saddle time 3 hours is doable if the ride is mostly under 90ish% of functional threshold power. And, I haven't noticed much of a change in appetite (more suppressed than an increase in general).
I rarely eat on a ride that's going to be less than 3 hours. Longer than that, and I have a bag of peanut M&Ms. Can dispense a few at a time with one hand on the bars, and close the bag up so they don't spill out. The sugar absorbs very quickly and the peanuts are a little bit of satisfying.0 -
TimothyFish wrote: »I think that depends on the person, but most of the guidelines I've seen say that you should eat if the ride exceeds 90 minutes. Some even say 60 minutes. For me, 90 minutes at 90% FTP would be 1,350 calories, which is just under the 1,400 - 2,000 calories of glycogen that is stored in the muscles. While that means I'm not in danger at that point, the reality is that I can't guarantee that a ride will stay under 90 minutes or that I won't push beyond 90% FTP. By the time I can answer that question with any certainty, I need to have already been eating.
You use some glycogen while in an aerobic state (don't recall where this is from but 5%-30% is from glycogen and rest from fat depending on the intensity) but nothing that would exhaust that supply in a 2-3 hour ride. Glycogen becomes the primary source of energy when you hit above critical power which is somewhere between 5%-10ish% above your FTP. Ability to stay in that intensity for up to three hours is a completely different subject. I guess if one can push there 95% of 20 minutes best average power to over 60 minutes, that becomes academic. I'm still struggling to hold threshold past 40 minutes on the best of days. Energy-wise there's plenty in the tank but I just can't deal with the fatigue buildup.
See:
http://jpansy.at/wp-content/uploads/2011/03/racing-by-power.pdf (specifically, page 16-18 on training zone and durations)
http://www.owascoveloclub.com/Education_files/EXERCISE PHYSIOLOGY.pdf
Info on anaerobic work capacity:
Skiba,et al. Modeling the Expenditure and Reconstitution of Work Capacity Above Critical Power” Medicine & Science in Sport and Exercise, 2012; 1526 – 1534
Gastin, PB. Energy system interaction and relative contribution during maximal exercise” Sports Medicine, 2001: 31(10): 725-41
Noordhoof et al. “Determining Anaerobic Capacity in Sporting Activities” Intl Journal of Sports Physiology and Performance, 2013, 8, 475-4820 -
jondthompson wrote: »So, I went and rode 76 miles at a 16.5 MPH average, which isn't abnormal for me. My cyclo computer estimates a 3766 calorie burn, during which I ate roughly 1232 calories. My normal daily intake, as prescribed by MFP, is 1630 pre exercise.
Anyhow, its saying I have 4164 calories to consume today... that's almost two large pizzas. I have no interest in consuming that much food, nor do I really need to. So.. is it ok to run a large caloric deficit when I ride a long distance such as this?
Depending on your fitness computer, the 3766 may include the calories required for your basal metabolism during the duration of your 76 miles, in which case your target for the day isn't 4164, but 3766 plus [(hours not cycling/24 hours) x 1630] - 1232 calories eaten.
You are not obligated to eat back all your exercise calories if you are trying to lose weight, only if you are trying to bulk.0 -
Jthanmyfitnesspal wrote: »
This is one of the reasons that people that understand how the process works rarely recommend HRMs as a method of establishing calorie expenditure. It's a reasonable corroboration mechanism when using other tools though.
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