Recommendation for dealing with long distance cycling in calorie counting.

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jondthompson
jondthompson Posts: 2 Member
in Fitness and Exercise
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?
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  • NorthCascades
    NorthCascades Posts: 10,970 Member
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    Save some of the calories for tomorrow. You might want them then.

    Your computer is overstating your burn. It's large, but not that huge unless all 76 miles were uphill into a headwind.

    Giant calorie deficits shouldn't be a regular thing, but you probably don't go this far every day. As an occasional thing is OK as long as you listen to your body.
  • JennyThompson180
    JennyThompson180 Posts: 17 Member
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    If I had those numbers, I would first double check the 1232 calories eaten during the ride. You haven't fueled that lengthy of a ride with these figures.
    Yes, there are multiple downsides from large deficits. Decreased performance, lethargy, hunger and muscle loss.
  • sijomial
    sijomial Posts: 19,811 Member
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    Your calorie burn seems very highly unlikely to be that high so doubt your deficit is that large. (Unless you are on a MTB going unusually fast perhaps?)

    When riding at a decent pace you can't eat (digest) enough to keep up with your calorie expenditure so a large deficit on the day of a big ride is likely. 90g of carbs/hr is sometimes quoted as the maximum (360cals of glucose/fructose).

    Once in a while isn't a big deal but you should go into a big ride fully fuelled and also eat for recovery.
    If you are riding next day as well then it's obviously more of a problem and you will need to eat more.
  • NorthCascades
    NorthCascades Posts: 10,970 Member
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    I've heard 250 cals per hour of sugar is the maximum you can process, so what you should aim to take in on a big ride.

    I bet it depends on the person.
  • Jthanmyfitnesspal
    Jthanmyfitnesspal Posts: 3,521 Member
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    The calorie estimate might be a bit high, but you certainly used something like 800 kcals per hour. I find with cycling that hunger hits the next few days. Actually, with this sort of exercise, it's easy to overeat in the off days due to an overcompensating appetite.

    http://www.runnersworld.com/fuel-school/how-to-avoid-weight-gain-from-marathon-training
  • jondthompson
    jondthompson Posts: 2 Member
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    I was definitely needing calories when I got home. As for the calculation's accuracy.. that was the most conservative estimate I had seen thus far. MFP wanted to hand me 7k calories, which I thought was a bit crazy. Strava is telling me 2500 cals, so I updated with that. It's supposed to rain tomorrow, so no ride. I got 3500 miles in during 2016 including four centuries, so I'm not new to long rides, nor how to prepare for or eat during, just combining with actually looking at my calorie balance.
  • Jthanmyfitnesspal
    Jthanmyfitnesspal Posts: 3,521 Member
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    Btw: awesome riding!

    MFP does not give highly accurate calorie estimates for everything.
  • NorthCascades
    NorthCascades Posts: 10,970 Member
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    I did 41 miles yesterday, at a much slower pace, but with ~3,800 (?) feet of vertical. Power meter got me at 1,650 kJ/kCal.

    Strava basically assumes you're riding alone with no wind, calculates the power you'd need to go the speed your file says you were going, and figures out the calorie needs for that for your and your bike's weight. It's probably one of the better ways to guess. It'll get it wrong if you're drafting, or there's a head or tail wind though.
  • Hornsby
    Hornsby Posts: 10,322 Member
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    sijomial wrote: »
    Your calorie burn seems very highly unlikely to be that high so doubt your deficit is that large. (Unless you are on a MTB going unusually fast perhaps?)

    When riding at a decent pace you can't eat (digest) enough to keep up with your calorie expenditure so a large deficit on the day of a big ride is likely. 90g of carbs/hr is sometimes quoted as the maximum (360cals of glucose/fructose).

    Once in a while isn't a big deal but you should go into a big ride fully fuelled and also eat for recovery.
    If you are riding next day as well then it's obviously more of a problem and you will need to eat more.

    This
  • sijomial
    sijomial Posts: 19,811 Member
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    NorthCascades wrote: »
    I've heard 250 cals per hour of sugar is the maximum you can process, so what you should aim to take in on a big ride.

    I bet it depends on the person.

    @NorthCascades
    That would be glucose only - 60g / hour is commonly given as the maximum.

    If you have glucose/fructose in a 2:1 ratio you get to the 90g amount. Different transporters and digestive pathways for the different sugars.
    But I'm sure there are personal variations as you say. I rarely manage to hit the maximum for my long rides as I can't fuel purely on gels/drinks and need some solid foods/snacks too to prevent nausea.

  • sijomial
    sijomial Posts: 19,811 Member
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    jondthompson wrote: »
    I was definitely needing calories when I got home. As for the calculation's accuracy.. that was the most conservative estimate I had seen thus far. MFP wanted to hand me 7k calories, which I thought was a bit crazy. Strava is telling me 2500 cals, so I updated with that. It's supposed to rain tomorrow, so no ride. I got 3500 miles in during 2016 including four centuries, so I'm not new to long rides, nor how to prepare for or eat during, just combining with actually looking at my calorie balance.
    My experience both when losing weight and tracking calories and maintaining without tracking....

    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.

    Garmin seems generally reasonable but on low intensity/low HR rides it seems to underestimate.
    Strava seems also to be generally reasonable for most rides.
    I also use a power meter equipped trainer but Wattbike use a peculiar algorithm that tries to take total metabolic cost into account rather than the more normal power X efficiency ratio.

    In the end I linked Garmin and Wattbike Hub to Strava and then linked Strava to MyFitnessPal. So really Strava is my "golden source" - I don't expect it be totally accurate but it is consistent and for finding a desired calorie balance reasonable and consistent works.

    In the end food logging accuracy makes a bigger impact than exercise logging accuracy even for long distance cyclists like us. A bit of common sense to make adjustments based on actual weight trends over time also works.
  • Machka9
    Machka9 Posts: 24,951 Member
    edited April 2017
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    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?

    I use two methods to calculate my calories:

    1) Strava

    2) 100 calories for every 5 km.

    76 miles is 122 km. 122 km would be 2440 calories by my 100 calories for every 5 km method. Happily Strava agrees ... sort of. Chances are it would give me 2100 calories or so.

    Therefore, just one large pizza will do. :)

    jondthompson wrote: »
    I was definitely needing calories when I got home. As for the calculation's accuracy.. that was the most conservative estimate I had seen thus far. MFP wanted to hand me 7k calories, which I thought was a bit crazy. Strava is telling me 2500 cals, so I updated with that. It's supposed to rain tomorrow, so no ride. I got 3500 miles in during 2016 including four centuries, so I'm not new to long rides, nor how to prepare for or eat during, just combining with actually looking at my calorie balance.

    Oh look! :smiley:
  • Machka9
    Machka9 Posts: 24,951 Member
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    You might also be interested in this: http://community.myfitnesspal.com/en/discussion/10366563/ultradistance-cycling#latest
  • jenilla1
    jenilla1 Posts: 11,118 Member
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    jondthompson wrote: »
    I was definitely needing calories when I got home. As for the calculation's accuracy.. that was the most conservative estimate I had seen thus far. MFP wanted to hand me 7k calories, which I thought was a bit crazy. Strava is telling me 2500 cals, so I updated with that. It's supposed to rain tomorrow, so no ride. I got 3500 miles in during 2016 including four centuries, so I'm not new to long rides, nor how to prepare for or eat during, just combining with actually looking at my calorie balance.

    Go with that (2500) and save some of your leftover calories for tomorrow's big feast! B)
  • TimothyFish
    TimothyFish Posts: 4,925 Member
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    I'm not going to say they cyclo computer is off because I seen similar number and I haven't been gaining weight. As for whether you eat all those calories on the day you burn them or not, my experience is that I'm more hungry on the day after a big ride. If I were going to put several days of riding together I might eat more the day of, but otherwise I just eat what I feel like eating for a couple of days.
  • bwogilvie
    bwogilvie Posts: 2,130 Member
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    50 calories per mile at 16.5 mph seems high, unless it was a very hilly or windy ride. My cycle computer (Garmin Edge 800) and Strava usually estimate 28-35 calories per mile, and the two are usually within 5% of one another.

    Your updated value from Strava seems reasonable. The way I approach such a deficit is usually a combination of eating over my goal for a few days before a long ride, running a moderate deficit on the day of the ride itself, then eating over my goal for a day or two afterwards. I usually track calories on a weekly basis anyway.
  • deannalfisher
    deannalfisher Posts: 5,600 Member
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    if you were to eat back about half your workout calories - that would be a total of 3533 for the day (1650+1883) - if you were to subtract the calories you took in during (1232) - that would leave you at 2301 for the rest of the day - nothing wrong with that if you break it down into pre/post workout food and regular meals
  • deannalfisher
    deannalfisher Posts: 5,600 Member
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    I do find on my long ride/run days if I neglect to eat enough after - that the next two days are going to be horrible because it will be like I can't eat enough
  • kcjchang
    kcjchang Posts: 709 Member
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    Sounds pretty high. The longest ride I done, in terms of saddle time, was a 89.5 mile with 11,588 ft elevation gain at 8:29 moving/10:23 total. Garmin (520/Connect) has me at 4,255 cals. The closest ride in terms of cal expendure to yours is a century last October (100.5 miles, 5:24 moving/6:10 total, and 3,586 feet elevation gain) in which Garmin credited me with 3,577 cals. I have a power meter and Garmin's estimates tend to be higher than what Strava gives me but not by much.

    Without the power meter, both Strava's and Garmin's estimates are rubbish. It's based on average speed and tends to be higher than MET.

    Except for my first two centuries, I generally can't eat much after the ride but catches up on the next two days.
  • Jthanmyfitnesspal
    Jthanmyfitnesspal Posts: 3,521 Member
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    kcjchang wrote: »
    Without the power meter, both Strava's and Garmin's estimates are rubbish. It's based on average speed and tends to be higher than MET.

    While I don't have one, that makes perfect sense to me. (For those who don't know: they are pretty expensive.) You certainly get excellent ride-to-ride energy expenditure data and the power meter tells you immediately if you are slacking off during a ride. All good stuff.

    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 would be very interested in a paper that compares all the methods (send it to me if you find one; note that the gold standard is oxygen consumption). Here are three methods that are all easy to implement on a cell phone:

    - GPS-based: Speed(t), grade(t), body weight, (age, sex?)
    - HRM-based: HR(t), body weight, sex, age (most systems use the same formula based on all 4 parameters)
    - Power-Meter-based: Power(t), (weight, age, sex?)

    Here (t) means "as a function of time."

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