LAURA Muir's World Athletics Championships debut came to an end on Friday evening, but the 20-year-old insists she is already a better athlete for her experiences in Moscow.

Kinross-shire's Muir had upset the applecart in qualifying for the 800m semi-finals after a strong finish in her first-ever world championships heat.

But the semi-final proved a stretch too far for the Scot, who came home seventh in a time of 2:00.83minutes, agonisingly outside her personal best. The pace was set too high for Muir, who, with her 1500m background, relies more on endurance than speed, but she insisted she had still learned a great deal from her global outdoor experiences.

"I was hoping I'd get a chance to run sub two [minutes], but that first lap was just so quick. I'm really happy with my performance and I got a personal best - I didn't expect to get through the first round yesterday so I'm pleased with that. It's a different race, a completely different race that I'm not so experienced with it, this will only be my fifth 800 of the year and two of those were at the European Under-23 trials, so I'm really pleased with it.

"I never dreamed of coming to Moscow this year, so this was a huge bonus and to get through the first round, I'm really delighted."

The British squad enjoyed an extremely successful Saturday in the Luzhniki Stadium, however, as Tiffany Porter and the women's 4x400m relay team both claimed bronze medals.

The British total now stands at five medals for the championships and it was the women's 4x400m team who started the fine showing. The British quartet of Scot Eilidh Child, Shana Cox, Margaret Adeoye and newly-crowned world champion Christine Ohuruogu finished third in a season's best time of 3:22.61 while the Russian team edged out USA for the gold in front of a vociferous home support.

And after that Porter blasted her way to third in a time of 12.55s as America's Brianna Rollins edged out Olympic champion Sally Pearson for the top spot on the podium in the 100m hurdles.