Laura Muir has been the undisputed queen of British middle distance for years. But after falling short in a world record attempt over 1,000m at the Emirates Arena in Glasgow she admitted a cold, hard truth: she now shares her throne with her young training partner Jemma Reekie.

On a day when Mondo Duplantis broke the world pole vault record for the second time in a week, the 21-year-old Reekie again showed off her devastating kick, emerging from the pack to zoom past the former world indoor silver medalist Dawit Seyaum in the final 20 metres to win the 1500m.

And Muir, 26, was clearly impressed. “I think we are very close to being on par,” she said. “Certainly Jemma has got the speed and I have got the endurance. I would probably give her the 800m and me the 3,000m and 5,000m. But at the 1500m we are very, very close. It’s really exciting at training. We’re pushing each other.”

Muir had been hoping to break Maria Mutola’s 1,000m world record of 2:30.94 but she was always off the pace needed and finished in 2:33.47 – a time that still admittedly beat Adelle Tracey by more than four seconds.

Meanwhile, Reekie’s victory in the 1500m early on in the day capped a remarkable fortnight in which she has shot from relative obscurity to Olympic contender.

Two weeks ago at this Arena, Reekie smashed the British indoor 800m record in 1min 57.91sec – shattering her personal best by nearly four seconds and setting the fastest time indoors by a woman since 2006. Last week, for good measure, she also broke the British indoor 1500m and mile record in a race in New York.

She had been hoping to break the 1500m again but in a more tactical race she showed another side to her talents by sprinting to win in 4:04:07. “There were a few points I had to get my elbows out,” admitted Reekie. “But that’s middle-distance running. I’m still learning but I’ve got a lot more to give. I was hoping I was going to beat my own British record,” she added. “But that’s OK. I’ll take the win.”

Jemma Reekie celebrates after winning the 1500m. Photograph: Ian Rutherford/PA

But Reekie also found herself having to defend her startling improvement and responded to questions for the first time about her controversial Nike spikes. “It doesn’t happen overnight and there’s a lot of hard work,” she told the BBC. “I am 21-years-old and I am a developing athlete and I am pushing myself to the absolute limits and I will just let my legs do the talking.”

Meanwhile the most surprising performance of the day was from full-time primary school teacher Jessie Knight, who set a stadium record with victory in the women’s 400m. The 25-year-old from Epsom combines a full-time job with training six days a week but showed plenty of strength to win in 51.57s – the third fastest time of the year so far.

“I got a stadium record and being on that start list, on paper I should have been last,” a bemused Knight said afterwards.