Runningart2004 wrote:
If a race has mile markers why would I need to use a GPS watch?
Alan
If a forum displays my name next to my posts, why would I need to sign each post with my name?
Roger
Runningart2004 wrote:
If a race has mile markers why would I need to use a GPS watch?
Alan
If a forum displays my name next to my posts, why would I need to sign each post with my name?
Roger
Back in the early 1980s when the rule changed from measure the runners most prudent path to shortest possible distance a my PR marathon came up about 150 yards short because of the ruling .
A great part of the distance change involved a very winding part of the course where the turns after the visible ones produced a counter intuitive road position. IE See a turn going right and down hill you run tight to to the right curb only to reveal the next turn is to the left and staying some distance away from the curb was actually the shortest possible distance. Actually a couple of [places had three consecutive turns involved in setting the actual shortest possible path.
My PR generated a lot of positive conversation and it was sad to find out the course was officially deemed short .
I think most people are overestimating how much distance is added by not running perfect tangents, but your 0.2 miles sounds about right.
Let's say the road is 50' wide and the straight between right and left turns is 1000'.
The perfect tangent distance is 1001.25'.
Assume you wait until the last 100' feet before you start the turn, then the distance is 900 + 111.8 = 1011.8'.
So you've run an extra 10 feet. You would have to do that 1,000 times to add two miles to the distance.
I would guess that weaving and running poor tangents would add a few hundred yards at most, which is just around that 2 tenths number.
It's the City of Big Errors
Some of the newer Garmins also come with an acceleramonter. That's an option in an area of low GPS coverage. I find the GPS to be a very handy tool for training.
IHaveATheory wrote:
so much GPS confusion wrote:GPS doesn't work in tunnels. It also doesn't work well between tall buildings and over bridges. It's officially called multi-path interference. There is no solution.
Garmins allow footpod switching, which seems perfect for Chicago. Footpod at the start, switch to GPS later.
Ok, it doesn't work in tunnels, but, does GPS melt steel beams?
The signal bounces off the buildings, sometimes multiple times, taking longer than expected to reach your watch. GPS depends on the time from satellite to your watch assuming a direct path. If it is delayed, there will be error in your position. It makes the calculated distance once you get a good signal longer.
Also, think radio. You get AM/FM radio between buildings, but not in tunnels.
Similar experience. Ran Chicago 8 years ago. It's the start that messed me up and I too got too anxious over.
I am running it again in 2017 and want to avoid confusion and anxiety and just get in a groove..
Anyone think starting the garmen at Mile 1 would be a good strategy? You can just mental note the clock as you cross the start line and subtract from clock at mile 1 for mile 1 time. If i complete mile 1 in 9:00, I would just add that to my overall time and factor accordingly throughout there course..this assumes gps is reliable after mile 1.
She probably was in the 4th wave, and started her GPS while moving up to the official start, and since she is probably a 4+ hour marathoner, she was more than likely in a mass of people, moving all around. It's possible.
Runtomrun wrote:
Similar experience. Ran Chicago 8 years ago. It's the start that messed me up and I too got too anxious over.
I am running it again in 2017 and want to avoid confusion and anxiety and just get in a groove..
Anyone think starting the garmen at Mile 1 would be a good strategy? You can just mental note the clock as you cross the start line and subtract from clock at mile 1 for mile 1 time. If i complete mile 1 in 9:00, I would just add that to my overall time and factor accordingly throughout there course..this assumes gps is reliable after mile 1.
Never heard of such a strategy. Seems like you would still get anxious when you see that you are in a crowd and not the running the tangents. In any event, GPS is dicey for about the first 3 miles while you are amidst the tall buildings downtown. It gets better after that.
Runtomrun wrote:
Similar experience. Ran Chicago 8 years ago. It's the start that messed me up and I too got too anxious over.
I am running it again in 2017 and want to avoid confusion and anxiety and just get in a groove..
Anyone think starting the garmen at Mile 1 would be a good strategy? You can just mental note the clock as you cross the start line and subtract from clock at mile 1 for mile 1 time. If i complete mile 1 in 9:00, I would just add that to my overall time and factor accordingly throughout there course..this assumes gps is reliable after mile 1.
No. Best strategy is to practice marathon pace diligently in the months leading up the race and run marathon pace. Don't watch your GPS pacing.
Cell towers sending same signals as they do to voting counters to up the numbers. It would have shown 50 miles if running through cemetaries.
Runtomrun wrote:
Anyone think starting the garmen at Mile 1 would be a good strategy? You can just mental note the clock as you cross the start line and subtract from clock at mile 1 for mile 1 time. If i complete mile 1 in 9:00, I would just add that to my overall time and factor accordingly throughout there course..this assumes gps is reliable after mile 1.
I ran it in 2016 and mine was way off for the first 4 miles and then within 5 seconds, except for mile 14 where it was off by about 20 seconds. I knew GPS would be unreliable, so I turned off auto lap and hit manual splits at the mile markers and didn't really look at watch pace in between. This worked really well for me and I was able to lock into a groove within the first 2 miles and for the most part just noted the split time as each mile passed rather than slowing down or speeding up. Doing this made me wonder about the additional energy cost associated with constantly checking watch pace and making adjustments.
Last year was 27.3, the year before was 26.8 for me according to Mr Garmin. I do enjoy hearing runners flip out during the run because their beloved GPS is off. Their tears are delicious and more hydrating than anything made by Gatorade.
I have a 6 mile course I've run hundreds of times with a GPS. I normally run the tangents but a dozen times I've deliberately run every turn in the "outer lane". No differences whatsoever. The inaccuracies of the GPS dwarf the few feet you gain/lose on running the tangents.
Yea last year it had me at 27.6 when I uploaded to strava, though my garmin only said 24.3... definitely not in line at all.. kinda weird. NOt near a lot of people so had to be the buildings and tunnel.