In the second part of our previews ahead of Sunday's SPAR European Cross Country Championships in Hyères, we focus on the men's and women's under-23 races.
Mayo ready to show age is no barrier
Moving to a new age group can sometimes prove tricky, with more experienced rivals and longer distances to negotiate.
These are the tests that Spain’s Carlos Mayo, 20, faces at the SPAR European Cross Country Championships in Hyères on Sunday but he has already proved this year how well he has made the switch to racing at this level.
Mayo won bronze in the 5000m at the European Athletics U23 Championships in Tallinn last summer and arrives in France as an interesting prospect after his double success in Samokov last year.
He left Bulgaria with two silver medals from the junior race, finishing 15 seconds behind Italian winner Yemaneberhan Crippa and celebrating again as he led the Spanish team to second place.
Then it was over a distance of 6.025km and this Sunday the challenge is 8.08km, in a field that includes one of the best in Europe at this age-group.
Belgium's Isaac Kimeli, 21, has run well in the CrossCup series this winter, and has a consistent record at these SPAR European Cross Country Championships. In 2012, he was sixth in the junior race and then won silver the following December in Belgrade.
In Tallinn, it was silver again in that 5000m race ahead of Mayo, so the pair meet again in different conditions in a race where the majority of nations are sending strong squads. The team medals will be hard to call.
Jonathan Davies will lead the British men, having been the first under-23 runner home in the trials in Liverpool, and their squad, which won team silver last year, once more includes Marc Scott, who was seventh in the individual race in 2014.
One place behind him in Samokov was François Barrer who is also back in a French team hoping to give their supporters something to cheer about.
And it will be a day very much about brotherly love too.
Twins Hans Peter and Manuel Innerhofer run for Austria, Italy’s team includes Nekagenet Crippa, the older brother of defending junior champion Yemaneberhan while Norway’s Filip Ingebrigtsen’s sibling Henrik runs in the senior race.
Men’s under-23 race: Start time: 12:26pm (CET). Distance: 8.08km
Carton the form runner in a race that's wide open
It is impossible to predict who will prevail in the women’s under-23 race because there are so many potential champions.
The Hippodrome du Var in Hyères could be treated to one of the closest finishes in the history of the event such are the number of athletes that have a winning chance.
Belgium’s Louise Carton is having a magnificent winter, winning consistently in the CrossCup series after a summer where, just like teammate Kimeli, she also won silver in the 5000m at the European Athletics U23 Championships.
In Samokov last year, Carton was seventh and while Great Britain’s Rhona Auckland is not back to defend her title, the field includes many of those who competed in that race.
Bulgaria’s Militsa Mircheva took silver only two seconds behind Auckland and will be in with a big chance again but this time without the support of the home crowd.
Sevilay Eytemis, of Turkey, was sixth and made the podium as her country won team bronze, while Alice Wright is back for Britain after finishing ninth, and winning team silver, while 10th in Bulgaria was Amela Terzic, the Serbian who then brilliantly retained her 1500m crown in Tallinn in a championship and national record (4:04.77).
Britain and Turkey are once again favoured to make the podium in the team competition as they bring strong squads to the race.
Laura Muir has been close to medals all year, finishing fourth in the 3000m at the European Athletics Indoor Championships in Prague and then fifth in the 1500m at the IAAF World Championships, while Turkey have the presence of Emine Hatun Tuna, who moves to this level having won junior gold in Samokov last year.
One of the spectacles of this 5.94km race will be how athletes more accustomed to shorter distances at championships use their speed. If they can save it for the finale, it could be quite special.
And it could mean an exciting time for the host nation as the French team includes Renelle Lamote, the European under-23 800m champion, while the Netherlands’ Jip Vastenburg has been running well on the cross circuit on the back of her 10,000m glory in Tallinn where, equally, that endurance puts her in with a good chance over this challenging course.
A fascinating race awaits.
Women’s under-23 race: Start time: 11:42am (CET). Distance: 5.94km