Probably a silly question, but what does the elevation change tell us ? if negative, was there more downhill sections on your route than up hill ? also, just to say i'm really impressed with this program, thanks !
Not a silly question at all, and gives me a chance to test my understanding.
Elevation change is the difference between the elevation at your starting point and at your finishing point. If you start and finish at the same place, this should be zero! The Boston Marathon would have a negative elevation change because the elevation in Hopkinsville is higher than that in Boston.
Elevation gain is how much your route rises during the run. Running a track will have zero gain, while running a hilly route will total the uphill distances during your run/ride. I don't think this can be negative: it only accumulates increases in elevation.
is there a way to show a graph of the elevation change through a mapped course?
But what is the purpose of the calculation if that is all it is doing? First of all, if I do a walk or a run, I am going to be using more energy if I go uphill halfway than if it had been all flat, EVEN IF I end up back at the starting point. Second, anyone who walks or runs (as opposed to riding a bike) will tell you that going downhill, you do exert some energy with your legs to maintain your speeed (you can't just "coast" on your feet). It might be less than if you were walking on flat ground, but it could actually be more, and it most certainly is not less to the point that it is equal in a negative direction to that when you are going uphill.
If you see here, for instance--http://walking.about.com/b/2011/04/13/how-many-more-calories-do-you-burn-walking-uphill.htm--you will see that people burn, on average, 60% more calories going uphill than if they are on flat ground, but burn less than 7% fewer calories when going downhill than if they were on flat ground.
So if someone is going to get any USEFUL workout information out of incluidng this information, your site's calculus should give the user, SEPARATE accounts of elevation gains and then elevation losses in their route, NOT the overall total of these two together.
What would be useful would be an output like this: 5.0 kilometers total, 2.5K with an overall elevation gain of 500 meters, and 1.0K relatively flat; and 1.5K with an overall elevation loss of 500 meters. With calculations of calorie burns for each using the above data. (If you wanted to get even more accurate, you cold add in an algorithm to give you better numbers based on a calculation of what the average gradient of the incline or decline was.)
Burntsox, thanks for the explanation. It's a bit silly to start and stop at different location. Don't you have to get back? LOL Unless you move house.
So now to see this elevation change, i need to turn off the "Complete there and back route".............hmmm just found out something funny, keep clicking that link and it will keep doing the complete route. So my 1 way trip is 15 miles, complete route is 30 miles, click complete route again and it jump to 60 miles, click again and 120miles. LOL No way to go back to 1 round route or one way trip.