A maths question?

subscriber

Im doin longford half on sunday which I want to run in 1.45 approx, but im not sure how to convert my pace as the course is marked in miles and I generally work in km.

So if I generally run 4.15 per km at race pace for a 5k and 10k but will want to slow that to prob 5.5 or 6 min per km to see me through the half. So how does that convert to min per mile? I only have a normal digital watch to pace me , nothing fancy like a garmin (yet) so thats why I need to get my min per mile pace.

ecoli

subscriber wrote: »

Im doin longford half on sunday which I want to run in 1.45 approx, but im not sure how to convert my pace as the course is marked in miles and I generally work in km.

So if I generally run 4.15 per km at race pace for a 5k and 10k but will want to slow that to prob 5.5 or 6 min per km to see me through the half. So how does that convert to min per mile? I only have a normal digital watch to pace me , nothing fancy like a garmin (yet) so thats why I need to get my min per mile pace.

1.45 is 8 min per mile exactly

subscriber

ecoli wrote: »

1.45 is 8 min per mile exactly

Very handy indeed, what formula can one use to figure this out in the future?

RayCun

this site

Pherekydes

Divide your finishing time by 13.1.

Incidentally, if you can run 42:30 for 10k you could aim for a bit faster than 1:45, maybe 1:36, which equates to 7:21/mile. Good luck with it. I still remember my first, and last, half.

ecoli

RayCun wrote: »

this site

More a fan of this one as you can get your mile splits to and also change positive and negative spilt running to

huskerdu

If you want to run 1.45 for the half ( 21km) , you need to run 5 min per km.

donothoponpop

huskerdu wrote: »

If you want to run 1.45 for the half ( 21km) , you need to run 5 min per km.

Bound to happen:D- the half marathon is 21.097494 kilometers. 21.097494 x 5 mins = 105.48747 minutes. Leaving you almost half a minute behind your target!

(Maths needs pedantry and precision!)

Oryx

This is probably too obvious but I'll mention it anyway. Miles to kms divide by 5 multiply by 8. Kms to miles divide by 8 multiply by 5. I always found doing mental arithmetic at each mile/km marker was a good distraction.

couerdelion

Oryx wrote: »

This is probably too obvious but I'll mention it anyway. Miles to kms divide by 5 multiply by 8. Kms to miles divide by 8 multiply by 5. I always found doing mental arithmetic at each mile/km marker was a good distraction.

I do that too.

I'm also forrever working out percentages in my head when running, especially on the treadmill. Or counting cracks in the pavement...

menoscemo

Oryx wrote: »

This is probably too obvious but I'll mention it anyway. Miles to kms divide by 5 multiply by 8. Kms to miles divide by 8 multiply by 5. I always found doing mental arithmetic at each mile/km marker was a good distraction.

Not extactly true, again to be pedantic (like d'pop) 5 miles is 8.05 km. Hence why 8 min/mile will get you a 1'45 half but 5 min/km will not.

Oryx

I know its not spot on but neither is my maths. It's close enough on the fly. And for my loose run targets

Cleanman

Oryx wrote: »

This is probably too obvious but I'll mention it anyway. Miles to kms divide by 5 multiply by 8. Kms to miles divide by 8 multiply by 5. I always found doing mental arithmetic at each mile/km marker was a good distraction.

Best distraction ever! I find that the longer the run, the more tired I am and the longer it takes me to do simple arithmetic!

RayCun

You should also print out a pace band, so you don't need to do any maths at the mile markers, just compare the number on your band to the number on your watch.