Well is the 8 miles at 5mph up and downstream or just downstream? Just downstream at 5 mph might be pretty easy and the cycling would be a lot more calories. Assuming similar times to complete the course and a similar effort level, the cycling would burn more calories. There is more muscle mass involved in cycling, which will result in more calories being burned.
Try comparing water needed in both.
Alternate days. It’s good to mix up your exercise, so paddle one day & bike the next.
I’m not sure but…
The energy cost of kayaking per unit distance (C(k), kJ x m(-1)) CAN be assessed at submaximal and maximal speeds. At submaximal speeds, C(k) can be measured by dividing the steady-state oxygen consumption (VO(2), l x s(-1)) by the speed (v, m x s(-1)), assuming an energy equivalent of 20.9 kJ x l O(-1)(2). At maximal speeds, C(k) can be calculated from the ratio of the total metabolic energy expenditure (E, kJ) to the distance (d, m). E is assumed to be the sum of three terms, as originally proposed by Wilkie (1980): E = AnS + alphaVO(2max) x t-alphaVO(2max) x tau(1-e(-t x tau(-1))), were alpha is the energy equivalent of O(2) (20.9 kJ x l O(2)(-1)), tau is the time constant with which VO(2max) is attained at the onset of exercise at the muscular level, AnS is the amount of energy derived from anaerobic energy utilization, t is the performance time, and VO(2max) is the net maximal VO(2). Individual VO(2max) should be obtained from the VO(2) measured during the last minute of the 1000-m or 2000-m maximal run. The average (SD) power provided by oxidative processes increases with the distance covered [from 0.64 (0.14) kW at 250 m to 1.02 (0.31) kW at 2000 m], whereas that provided by anaerobic sources would show the opposite trend. The net C(k) is a continuous power function of the speed over the entire range of velocities from 2.88 to 4.45 m x s(-1): C(k) = 0.02 x v(2.26) (r = 0.937, n = 32).
I might be off by a decimal point or two ;-)
examples from my training log
I am using both Polar HRM and GPS. A few examples from my training log if we can believe the estimation of total burnt calories from the HRM.
Sisson kayak, 5 mile time trial on a shallow lake, wind 10-20m/s
time: 0:52:11, HRM 149, 813 calories, 30% from fat
ALLY 560 folding kayak, 5 mile time trial on a shallow lake, calm
time: 0:58:14, HRM 144, 856 calories, 35% from fat
Sisson kayak, upstream/downstream paddling on a fast, twisty, shallow river (Big Thompson), 3.4 miles total
time 2:06:39 (~1:18:00 moving time), HRM 125, 1406 calories, 45% from fat
Sisson kayak, upstream/downstream paddling on a South Platte River, 18.9 miles total
time 6:58:00 (~5:47:00 moving time), HRM 125, 4679 calories, 50% from fat
road bike, easy riding on bike trails, 20.5 miles
time 1:37:42, HRM 122, 1041 calories, 50% from fat
hiking with trekking poles, foothills, 6.9 miles
time 2:02:46, HRM 115, 1115 calories, 55% from fat
You can check speed and HRM of some real racers on my virtual race pages:
HRM based calorie comparisons
Haven’t compared lately, but use HRM a lot. I estimate:
3 mile jog/run = 6 mile x 5mph paddle (out of a 12-18 miler) = 12 miles at 15-18 mph road bike.
Your intensities/speeds may be a bit higher. I do a bit more than these distances (especially paddling) - but these are where the calorie burn coincides when divided out. Nice even multiples. Would not apply to longer marathon/endurance events - just to fat middle aged guy doing exercise. My HR is similar paddling and cycling - higher running since I’m a tad heavy and have to counter gravity.
More simply put…
It turns out that biking uses more muscle mass and is likely a more aerobic activity than using the relatively small muscle groups of the upper extremities of kayaking. More oxygen consumption = more calories burned.
Biking at the above pace is likely falling within a 12 MET range (1 MET = rest), while the kayaking is somewhere from 7-11 METs.
If all variables are controlled for (wind, temp, body wt., etc. etc.) the biking probably yields a greater caloric expenditure for equal time frames.
Wouldn’t a good scale, accurate to the tenth of a pound tell the story? Weigh yourself before and after the efforts. Allow yourself one water bottle only. No peeing 'til you’ve weighed yourself at the finish. What better, cheaper way is there than that?
Measuring one’s pre/post exercise weight change from fluid loss does not provide any useable data in the determination of caloric expenditure.
what type of bike
how many calories you burn on a bike (assuming speed and distance are held constant) has a TON to do with whether you’re on a road or mountain bike and whether the terrain is flat or not etc.
What he said…
If you use less muscles paddling…
… than you do cycling - you might want to re-evaluate your stroke!
Cycling = lower body. Kayaking + whole body!!! Torso IS large muscle groups + legs + shoulders/arms (in order of engagement - and what should feel most worked after a good paddle).
The sweat lost from the body might not be equal, even if the calories burned were, is that right? Makes sense. The wind blowing across you on a bike at 20 mph should make you sweat less, even if your effort is the same as paddling.
That is what I do…
…and then the third day I am building a small house.
sorry but cycling uses more muscle mass
The highest VO2 values come from cross country skiing followed by running and cycling. Sports like swimming have lower V02 max values. And yet in swimming you are using both upper body and lower body. Canoeing/kayaking won’t be much different. Yes if you use the correct paddling technique, you will use your legs some, but it is only a small range of motion. The glutes are the largest muscles in the body, and you use them a lot more in cycling than paddling. You may not be rotating in cycling but your midsection is definitely working in trying to stabilize the body. If you haven’t ridden much and go try to ride a lot of hills, you most likely will wind up with a sore lower back.
Your caloric expenditure is equal to five Kcals per liter of oxygen consumed. The higher the VO2 (volume of oxygen consumed) required for an exercise, the more calories being burned. Unless you are very highly trained for paddling and completely untrained for cycling, you will more than likely have a higher VO2 max during cycling.
... you've never seen Barton race!
Even a slug like me, who paddles more than cycles - can burn very similar calories and maintain similar heart rates doing either.
When's the last time you paddled for more than 3 hours at greater than 5mph average speed? If you're going to compare to road cycling - compare at similar output levels over time. If you don't have similar output levels - your opinion is biased by slow short paddles and long hard rides. In that case - your experience only applies to you.
if you knew me
Actually i’ve raced canoes for 5 years. I race against Greg Barton’s brother and sister (Bruce and Connie - not as good as them) on a near weekly basis once the season gets into full swing. So yes I have a good idea what their paddling styles look like. And I raced bikes for 9 years. If you want to compare Lance’s VO2 max on the bike to Greg Barton’s VO2 max in a kayak, I will guarantee that Lance’s VO2 max will be higher than Greg’s. I’m not saying canoeing/kayaking aren’t good aerobic sports (i compete in canoe racing), I’m just being realistic. I have my masters degree in exercise physiology. If you want proof of this get the book Endurance in Sport by IOC. In a study by Neumann (1988), typical values of maximal oxygen uptake in road cycling are 70-75 (60-65 in women. Typical values in canoeing are 60-68 (50-55) in women).
According to fitday.com
1 hour of biking at the speed you mentioned would be 694 calories
1 hour of paddling would be 378 at the speed you mentioned.
You just have to do more paddling, which isn’t so bad.