What uses more energy, climb up a hill fast or climb slow??
07-22-22, 02:31 PM
#126
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07-22-22, 02:34 PM
#127
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Sure but most of the energy at "reasonable" speeds is for overcoming gravity.
2 miles
0' at 5 mph = 25 kcal
5' at 5 mph = 181 kcal
10' at 5 mph = 338 kcal
0' at 10 mph = 50 kcal
5' at 10 mph = 207 kcal
10' at 10 mph = 364 kcal
0' at 15 mph = 91 kcal
5' at 15 mph = 248 kcal
10' at 15 mph = 404 kcal
Bicycle Speed (Velocity) And Power Calculator
2 miles
0' at 5 mph = 25 kcal
5' at 5 mph = 181 kcal
10' at 5 mph = 338 kcal
0' at 10 mph = 50 kcal
5' at 10 mph = 207 kcal
10' at 10 mph = 364 kcal
0' at 15 mph = 91 kcal
5' at 15 mph = 248 kcal
10' at 15 mph = 404 kcal
Bicycle Speed (Velocity) And Power Calculator
07-22-22, 02:38 PM
#128
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That is what both of us are saying. PE= mgh dominates when you are climbing a significant hill. Your mass doesn't change. The height doesn't change. The gravitational acceleration g doesn't change. (I assume we are talking about speeds at which relativistic corrections don't need to be applied.)
You are only consuming more by a factor of 0.13x (about the same total consumption). But the rate is about 2x more (5mph -> 10mph).
Things are more complicated than this because there's also more airflow at higher speeds. It seems that the convective heat transfer at 10mph about 1.5x of that at 5mph.
https://www.sciencedirect.com/scienc...60132320307940
Last edited by njkayaker; 07-22-22 at 02:53 PM.
07-22-22, 03:03 PM
#129
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Note we're discussing energy, NOT power. Joules vs Watts
And for the sake of simplicity, we'll ignore aero drag, ignore rolling resistance and all other sources of friction on the bike including losses due to cycling technique. Thanks.
I've been thinking lately if climbing slowly isn't doing me any favor in long rides especially when I'm trying to be home before the sun is straight up and before temperatures climbed to 100F.
And for the sake of simplicity, we'll ignore aero drag, ignore rolling resistance and all other sources of friction on the bike including losses due to cycling technique. Thanks.
I've been thinking lately if climbing slowly isn't doing me any favor in long rides especially when I'm trying to be home before the sun is straight up and before temperatures climbed to 100F.
There are calculators that will let you figure it out more accurately.
For a run of 2 miles, you'll consume about 14% more energy talking about "moderate" grades and "reasonable" speeds.
0' at 5 mph = 25 kcal
5' at 5 mph = 181 kcal
10' at 5 mph = 338 kcal
0' at 10 mph = 50 kcal
5' at 10 mph = 207 kcal
10' at 10 mph = 364 kcal
0' at 15 mph = 91 kcal
5' at 15 mph = 248 kcal
10' at 15 mph = 404 kcal
Bicycle Speed (Velocity) And Power Calculator
07-22-22, 03:09 PM
#130
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I'm starting to run out of space to carry food that I'm able to access with ease without stopping. I'll have to figure this one out first. I didn't want to put anything in my pockets to maximize cooling.
I've been thinking of using some cheap bottle holders that installs on the handlebar but instead of holding a bottle, it will hold a big open cup with food in it sliced to bite sized pieces I can just pick up. Or just find the cheapest place along the route for quick refuel!
I've been thinking of using some cheap bottle holders that installs on the handlebar but instead of holding a bottle, it will hold a big open cup with food in it sliced to bite sized pieces I can just pick up. Or just find the cheapest place along the route for quick refuel!
Long distance riders manage it. It's not uncommon to ride for 62 miles without stopping (literally). These riders carry food to eat while they ride but don't carry all of what they will eat. Many of these riders use handlebar bags (that they can reach into while riding).
07-22-22, 03:31 PM
#131
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Air flow over sweat dissipates heat as well. I don't find I sweat more climbing fast than slow, and ambient temperature is by far the bigger factor in the amount of sweat generated. If it's hot enough, I don't have to be doing much of anything to sweat profusely. In other words, sweat is a really bad indicator of effort.
Effort generates heat and produces sweating which is why people can sweat heavily even when the ambient temperatures are well below freezing.
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07-22-22, 03:39 PM
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07-22-22, 05:19 PM
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07-22-22, 05:23 PM
#134
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Sweat evaporates very efficiently with an air flow, so I can put out a huge effort on a cool day and regulate my body temperature with very little sweat at all. On a very hot day, I'll work up a major sweat walking to my car.
Go out riding in shorts below freezing and work up a sweat. I double dog dare you.
07-22-22, 05:50 PM
#135
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Of course, you should always cover your knees in cold weather.
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07-22-22, 06:03 PM
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I dragged a 200 pound buck 2 mile out of a ravine in the dark in -5F temps with just my t-shirt on top. It was a 90 minute threshold effort and I was soaked, drenched.
07-22-22, 06:04 PM
#137
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Not true. Your total energy expenditure is spread out over more time. This makes less energy per set distance. Anybody who has ever rode a bike knows it is harder to go faster, no matter what.
07-22-22, 07:42 PM
#138
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My theory is that since I'm not racing or shooting for some platonic ideal of my best speed, I just do whatever works without making myself miserable, the high number of miles is enough to satisfy me. I typically have a full sit-down meal at the half-way point of any 3 digit mileage ride, which is why I have so literal tolerance for the "your maximum blah, blah, blah is" crowd. It has the added benefit of getting me out of the sun and heat for a while, which definitely helps with tolerating the ride back. For example, I had my lunch at mile 70 of a 140 mile ride last Saturday, and it was not a small meal. Funny thing, I was just fine on the ride back, but I did stop for a piece of cake and some coffee at mile 92, and at a convenience store for water and a pee at mile 108. Miles 130-135 were a complete pain in the butt. Unbeknownst to me, they started milling the stretch of road, so I was committed to that route before I knew how bumpy it would be. Now that occurring at that point in the ride made me feel damn tired..
BTW, it was a hot day, so I took the hills as fast as I could throughout the day as crawling uphill on a hot day definitely makes for a sweaty misery.
I tried mounting water bottles on my handlebars, and I didn't get through a single ride before they started popping off.
BTW, it was a hot day, so I took the hills as fast as I could throughout the day as crawling uphill on a hot day definitely makes for a sweaty misery.
I tried mounting water bottles on my handlebars, and I didn't get through a single ride before they started popping off.
It just didn't occur to me to put extra work on the climbs. Not until this thread and since I have real easy low end gears for climbing, I tend to take advantage of it, spinning away lazy on climbs. But tends to stretch the rides and eventually, my neck and butt starts to hurt a bit.
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07-22-22, 07:44 PM
#139
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No one's questioning whether your body makes more heat with higher effort and if that heat needs to be dissipated, you will sweat.. The issue is that there's so many other things that also affect the quantity of sweat that it's a notoriously bad indicator of the level of effort. We haven't even mentioned humidity yet, which of course affects how fast the sweat evaporates. That can make the same amount of sweat seem like it's a lot more--in other words, I don't think we're even good at comparing how much we're sweating at different times.
07-22-22, 08:12 PM
#140
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You were probably sweating the same amount, but it evaporates more slowly when you aren't moving.
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