är detta en bra tid? Och hur kan man förbättra det?

Ja det är bra. 1,6 km är ju en mile. Googla 6 minute mile om du vill veta mer om bra eller dåligt.

Running Level, which reports average running times based on age and ability, reports that a good mile time is 7:04 across all genders, and a good mile time for a male is 6:37, and a good mile time for a female is 7:44. These times are based on an intermediate level runner.

marathonhandbook.com/is-a-6-minute-mile-good/