Burning the most calories

bcdudley1

I ride my bike about 3 times a week, doing about 25 miles. Typically I will go all out as fast as I can with my heart rate at max. I have been doing it for many years, so I am comfortable with it.. In the last week, I tried working within my heart rate zones, meaning I stayed in the hard, cardio and fat burn zones, and never hit peak. Wahoo says i burned almost twice as many calories this way. I felt like I didn't even get a workout. I was never out of breath and not sore at all afterwards. Did I really burn more calories that way, or is it being miscalculated?

cmriverside

Are you calculating time and distance?

bcdudley1

Yes, I am using Wahoo which tracks GPS, speed, cadence and heart rate. It also knows my height and weight.

cmriverside

Tagging a couple cyclists, maybe they're around...they would know.

@sijomial
@lorrpb
@NorthCascades

L1zardQueen

Tagging @heybales also. Piggybacking.

Djproulx

I will defer to the expertise of the MFP folks mentioned by @cmriverside above, but in the meantime, a couple questions to help understand your data a bit, since I use Garmin devices.

Since you said you went for 25 miles, Im assuming this means that you rode outdoors, as opposed to an indoor Wahoo trainer. If so, then I'm guessing that your Wahoo device is a bike computer that reads a chest strap heart rate monitor, is that correct? I'm also assuming that you are not using a power meter and have not done a Functional Threshold Power test (FTP) on your bike. If all of my assumptions are true, then I'd say that the Wahoo is using HR and perhaps your inputs to provide a calorie estimation.

I have a power meter on my bike which measures the actual work done in kilojoules. There are roughly four kj's per food calorie, so the power meter provides a reliable source of calorie data. With that said, I've found the biggest driver of variances in calorie expenditure is TIME in the saddle, as opposed to intensity. I'll give you an example to illustrate.

On April 14, I rode my bike indoors for 1:01:02 and burned 584 calories. This was a ride where I spent 55% of the time in HR Zone 2- an Aerobic ride. I spent another 30% of the ride in HR Zone 1 - Active Recovery (Easy).

On April 26th, I rode indoors for 1:00:00 and burned 605 calories. This ride was a very hard, unpleasant effort known as an FTP test. After some warm up drills, I spent 30% of the time in HR Zone 3- Tempo, 27% in HR Zone 4, - Threshold and 6% in Zone 5, VO2 Max. This was NOT fun, but calorie burn was very close to the earlier ride.

Finally, to illustrate the point further, on April 25th I rode outdoors for 1:54:31. This was a 32 mile ride where 60% of the ride was Z2 -Aerobic and 40% of the time was in Z3 - tempo. The calorie burn for this ride was 1069. So my point is that for me, time is the biggest driver of different calorie burns, as opposed to the variances in intensity (within reason.) Look forward to hearing from others who have experience regarding wahoo measurements.

heybales

Almost sounds like a typical group ride with enough enthusiasts to keep it hard.

This is just about the HR-based calorie burn formula. Could happen running or rowing too. Biking just gives an easy method (power meter) to get correct figures for comparison.

The formula for calculating calories from HR is only a decent estimate in the aerobic steady-state zone.
So right above daily activity level, most studies have found flex-point at about 90, to right below anaerobic zone - and that point is highly variable depending on genetics and training.

Both ends of that range are the most inaccurate compared to the middle part.

The major issue is while the 90 isn't a bad estimate - the anaerobic threshold (AT) or lactate threshold (LT) is totally an estimate based on other factors - BMI, restingHR, age, ect.

The HR zones you were training to are most likely based on HRmax (maybe includes restingHR if using HRR method) - and unless you tested and input that figure, it also is an estimated figure based on age, perhaps restingHR, BMI, ect.

So you have this straight line function starting at 90 and going upwards to some who knows how accurate figure.
Probably not very accurate if using 220-age.

Here's mine - cal/min from VO2max test, where I was mainly interested in getting my AT/LT line for training purposes.
Decently straight. Below and above this it's not straight anymore, diverges from the line. I left those value out.
This gave me the ability to create a calorie burn formula as long as HR was within that range.
(had some other things going on in that graph too that don't apply)





I'm curious if your normal riding at max effort (it isn't HRmax if sustained more than a min and not quickly reached in 8-12 min) is above your estimated HRmax - which would tend to totally throw off the formula if riding above it.

What kind of avgHR and maxHR do you get at end of typical rides?

How about on this zone test ride?

sijomial

Sounds very odd and am looking forward to hearing the clarification of the details from you OP.

Additional question to those above and assuming you aren't using a power meter:
Do you feed your rides from your Wahoo bike computer into Strava or another app?
Is this an outdoor route you have done before and can compare rides and data?

BrianSharpe

sijomial wrote: »

Sounds very odd and am looking forward to hearing the clarification of the details from you OP.

Additional question to those above and assuming you aren't using a power meter:
Do you feed your rides from your Wahoo bike computer into Strava or another app?
Is this an outdoor route you have done before and can compare rides and data?

^^ This, without knowing wattage it's hard to compare and/or determine how accurate either may be.

Duck_Puddle

Also curious if when you say you go “all out as fast as you can with your HR at max” is that a sustained thing?

Typically “all out as fast as you can go with HR at max” is not sustainable for more than a short period of time so that kind of effort is usually part of intervals (with alternating short periods of max effort and recovery/rest),

If your “all out” efforts are intervals rather than sustained, then you almost certainly burned more calories at a sustained lower intensity.

Also - are you using wahoo computer or the phone app? If the phone app, have you run any other GPS apps or reviewed the map to confirm the GPS track is accurate? While that doesn’t matter too much for calories-my wahoo app tends to be exceedingly generous with distance for my runs & rides.

djaxon1

I also find Time relates to cals most.
I only walk incline treadmill 15% / 18% age 61
Usually HR keeps rising to max ,seen 173 -45min @15% , 30m@18%
keeping HR under 140 just seems so easy but calory count still adds up !