Sondre Moen was always a great running talent. 14.02 as 17 year old.
After he was 20 he has struggle to keep improving, but he has always kept training.
Last weekend he ran the half marathon in 59.47. That was not only national record but also one of the fastest time of an European born runner.

How did he do it. A lot of training.
I will recommend you to read some of his training here.http://www.letsrun.com/...d=8495930&page=4


Examples:


Friday 15 (Sestriere, track) :
2 x 3000m (rec. 2'55") in 8'58"1 - 8'58"3 (rec. 2'54") +
3 x 2000m (rec. 2'55" >< 2'57") in 5'56"0 - 5'57"3 - 5'56"2 (rec. 2'55") +
5 x 1000m (rec. 1'54" >< 1'56") in 2'51"3 - 2'54"4 - 2'54"1 - 2'53"9 - 2'54"6 (rec. 1'58") +
6 x 500m (rec. 1'25" >< 1'30") in 1'22"1 - 1'22"5 - 1'20"4 - 1'19"4 - 1'19"5 - 1'20"4

Monday 18 :
12 km climbing (Cesana - Sestriere, from 1350m till 2050m with 700m of difference) in 44'23"

Thursday 21 : 45 km in Valle Argentera (1700 < 1800m) in 2:41'08" (average 3'35")

Saturday 23 : 50' Fartlek (15 times 1' fast - 1' moderate + 20 times 30" fast - 30" moderate) (15.9 km, average 3'08"4)

Tuesday 26 (Special Block) :
Morning : (Valle Argentera) : 10 km in 33'16" + 12 km in 36'35" (average 3'03")
Afternoon : 10 km in 37'10" + (Track) 15 km with 6 x 1000m in 2'48"2 >< 2'55" recovering 200m easy in 61" >< 66" +
10 x 600m in 1'42"8 >< 1'45"1 recovering 200m easy in 64" >< 70" (total of the day : 47 km)