An outstanding 41-year old American with just 14 race days in his legs, fatigued Tour de France stars, a Giro champion on the rise and a resurgence of a former grand tour winner have been some of the headlines in a highly entertaining first week of the Vuelta a Espana. At the moment, pre-race favourite Vincenzo Nibali finds himself up against two veterans that may prove to be his biggest challengers. CyclingQuotes takes a look back at the first 10 stages as we ask ourselves what we have learnt from the first part of the race.

A few weeks ago Andre Noe held the record as the oldest leader of a grand tour. The Italian was 38 years of age when he got a brief stint in the maglia rosa in his home grand tour in 2007 while he worked as a domestique for eventual winner Danilo Di Luca but was never seen as a realistic winning candidate.

People may have had the same assessment of 41-year old Chris Horner's overall prospects when the American briefly rode himself into the red jersey in the Vuelta a Espana with a stunning ride up the Mirador de Lobeira on stage 3. When he lost the jersey by virtue of an unfortunate split, the Radioshack rider was not too unhappy: he made it clear that he was in Spain to wear the coveted tunic on the final day in Madrid.

People may have put an indulgent smile on their faces when listening to Horner's statements but it was no case of misjudgment of his own capabilities. With his stunning ride on Alto de Hazallanas, he not only rode himself back into the leader's jersey, his win was by such a dominant margin that he now finds himself as one of the outstanding favourites to win the race overall.

Few pundits had pointed to 41-year old Horner as a real winner candidate. CyclingQuotes was one of the select medias to name the veteran as a podium contender but it was probably only the American himself who really believed that he was even more than that.

Horner's age and lack of racing - due to a knee injury, he had only 14 days of pre-Vuelta competition in his legs this season - may be eye-catching but his performances should not come as too big of a surprise. Few riders have had more crashes than the American who has raced as a domestique for most of his career. He was Cadel Evans' trusted lieutenant at Lotto for a couple of years before moving into a support role at Astana and Radioshack, working for the likes of Lance Armstrong and Levi Leipheimer. When all the grand tour stars faded in the 2010 Tour de France, Horner was, however, the man to save the race for Johan Bruynell's star-studded line-up by finishing 9th overall despite having lost plenty of time in the opening part of the race when he had not planned to contest the GC.

Few riders have had more bad luck than Horner. He was poised for a great Vuelta in 2009 when a crash on a slick road in Liege put an end to his hopes. In 2010 he crashed out of the Tour de France in dramatic fashion and his 2012 season was marred by illness which didn't prevent him from finishing 13th overall in the Tour. His knee injury was just the most recent obstacle that has prevented him from revealing the true extent of his potential.

When he last competed on European soil, he climbed alongside the likes of Chris Froome, Vincenzo Nibali and Alberto Contador, and that should have been a clear warning to his rivals who have been too busy looking at each other to really worry about their American challenger. That may now prove costly as the American has a healthy 43-second lead over Nibali.

In the Tirreno-Adriatico, Horner dropped down the GC in the final time trial and it is once again the race against the clock that is his biggest obstacle. It has always been about limiting his losses in the timed events and that will be the case again when racing resumes on Wednesday. He may have won the Vuelta al Pais Vasco in 2009 by virtue of an outstanding ride against the clock but that was on an extremely hilly course in the Basque Country. Tomorrow's route is certainly not flat but the gentle gradients don't play into the hands of the veteran American. On the other hand, none of his rivals are TT specialists either and most will enter the TT with a similarly defensive approach. If they fail to make up time on Horner tomorrow, they will have to do so in the mountains and that has been an impossible task so far.

Nibali on the rise

While the time trial represents an opportunity to put Horner under pressure, the first week was a missed opportunity to gain time on Vincenzo Nibali. The Giro winner had done nothing to hide that his worlds ambitions forced him to enter the race slightly below his highest level and the early days confirmed his own assessment when he struggled up the climbs during the first few days.

His rivals failed to deal him a blow during the opening week and now it may be too late. He made a respectable ride up the ramp in Valdepeñas de Jaen to prove that his form was on the rise but it was his performance on the steep Alto de Hazallanas yesterday that finally showed that Nibali is back in business. No one doubts that Nibali will only get better from now on and it must be a cause for concern for the likes of Alejandro Valverde and Joaquim Rodriguez that they enter the first rest day with a deficit compared to their biggest pre-race rival. Aided by an outstanding team time trial, Nibali could probably not have wished a better outcome of the first week.

The first, explosive part of the race played into the hands of Nibali's Spanish rivals but now we enter the Italian's preferred terrain in the high mountains. While not an outstanding time triallist, Nibali may still consider the 38,8km ride against the clock as another opportunity to gain time on his rivals. Horner is the only rider who can allow himself to follow wheels. All other winner candidates have to go on the attack and their biggest hope may now be that Nibali has one of those bad days that have so often hampered his grand tour campaigns. He didn't have one in the Giro and has improved his consistency with age. The Spanish home crowd will hope that he hasn't completely stepped into the adult world just yet.

The resurgence of Basso and Pinot

If Nibali has a jour sans and Horner fails to keep up the tempo, the man to capitalize could be another veteran. 35-year old Ivan Basso has mostly been regarded as a rider of the past but has been one of the strongest riders in the first part of the race. Actually, his strength should come as little surprise. When he has failed to perform in grand tours since his 2010 Giro win, it is mostly due to crashes that have hampered his build-up. That was what put his 2011 Tour and 2012 Giro ambitions on hold but this time he has had his first seamless preparation for more than 3 years.

While there may be some uncertainty regarding Horner's ability to keep up the pace throughout the entire three-week race, there's no reason to fear any breakdown from Basso. The Italian is a master of consistency and only gets better as a three-week race goes on. While most of his rivals feel the fatigue at the end of a long season, Basso has had limited racing, having cancelled his Giro participation due to a perennial cyst. The long Pyrenean stages and the brutally steep Angliru only play into the hands of the rider who laid the foundations for his 2010 Giro win on the equally steep Monte Zoncolan. If he manages to limit his losses in the time trial, Basso may not have won his final grand tour.

Another resurgence has been delivered by Thibaut Pinot. Again there's no reason to be too surprised. During the spring season, the Frenchman gave lot of indications that he had stepped into the world elite of climbers but his bad descending and vulnerable mind only drew negative headlines during the Tour. Like Basso, he has limited his losses during an opening week that didn't play to his strengths and now only has to overcome the time trial before getting into his preferred terrain. His descending once again lost him time in Valdepeñas de Jaen and could do so again later in the race but on a course that suits him down to the ground, Pinot has every reason to believe that he could make it into the top 5 in a grand tour this year.

Tour de France fatigue

During the 2000s, only Carlos Sastre and Joseba Beloki have managed to finish on the podium in both the Tour and the Vuelta in the same season, and it is testament to the difficulty of the Tour-Vuelta double that not even Chris Froome managed to repeat the feat last year. Few will have forgotten how strong the Brit was in the beginning at the race before ultimately finishing a distant 4th, more than 10 minutes in arrears.

Hence, it was always risky business for Alejandro Valverde and Joaquim Rodriguez to target a top performance in the Vuelta on the back of what had already been a very tasking Tour. Unlike Froome, the two Spaniards even have a hard Ardennes campaign in their legs to further increase their fatigue.

Until now, the duo has raced a solid race without losing too much time and always staying with the best in the mountains. However, it is also evident that they lack the strength that allowed them to shine on the French roads in July. Valverde may not be too far from his best but for Rodriguez to struggle on the ramp in Valdepeñas de Jaen is very unusual.

What may be of even more concern is that nothing suggests that they can expect to see any kind of improvement. The fear has always been that the fatigue would catch up with them during the hard third week and so it may be worrying that they have not even been at their best in the beginning of the race. Fellow Tour de France stars Bauke Mollema, Roman Kreuziger and Laurens Ten Dam have already vanished into anonymity. While Valverde and Rodriguez may escape a similar sad fate, it's hard to imagine one of the home favourites on the top step of the podium in Madrid.

Sky failure

Team Sky is known as the world's strongest grand tour team. This time they may not have had the likes of Chris Froome, Bradley Wiggins or Richie Porte at their disposal but there was no reason to be too pessimistic. With Sergio Henao as leader, the team had lined up one of the most promising grand tour stars who was reported to be in the form of his life and whose palmares indicated that he could put the race on fire like his compatriot Nairo Quintana had done in the Tour.

However, it all came to nothing on the first mountain stage when the young Colombian forgot to eat and fell out of podium contention due to a hunger flat. He tried to fight back in the next stages but with a demoralized mind, he has been unable to keep up with the best whenever the going got tough. Not even the steep ramp in Valdepeñas de Jaen which is tailor-made to his characteristics, allowed him to shine.

The below-par performance of teammate Rigoberto Uran has been less of a surprise, and Team Sky now finds itself in the unusual position of not having a genuine GC candidate. Uran is 15th on GC while Henao is an even more distant 23rd and nothing suggests that they will be able to turn things around dramatically. The team has been unusually active in the early breaks, even putting Luke Rowe and Christian Knees into suicide attacks, and we may now see the Brits fully embark on a race as stage win seeking attackers.

A repeat story for Gilbert?

When Philippe Gilbert won two stages of last year's Vuelta and went on to crush the opposition at the world championships, everything suggested that his fortunes had finally changed. His season in the rainbow jersey has suggested otherwise and there has not been too much of a difference between Gilbert's 2012 and 2013 campaigns.

While this has been a cause for concern for Gilbert during the opening part of the season, the similarities may now spur some optimism. Last year, the Tour de France set him up for a good ride at the Vuelta and a dominant performance at the world championships. He still hasn't won a stage in this race - partly because of a knee injury that put an end to his hopes on stages 3 and 4 that were tailor-made to his characteristics - but his recent showing has been the strongest of the entire season. Combining forces with an in-form Zdenek Stybar, he held the peloton at bay on stage 7 and was only narrowly edged out by the fast Czech in the sprint. The steep ramp in Valdepeñas de Jaen is usually too hard for the world champion but when he is at his best, he may even handle those kind of excessive percentages. An 8th place finish indicates that he is not too far from his best level.

Like last year, that may set him up for another beautiful showing at the world championships. The final part of the Vuelta doesn't suit him too well and so he may not take that elusive win in the rainbow jersey. His only chance may be to get the chance to ride in the coveted tunic for another year and indications are that he may actually go on to earn himself another big win in Florence later this month.

To win that race, he will have to beat an in-form Fabian Cancellara. Already at the team presentation, it was evident that the Swiss had lost weight and prepared himself well for what has been described as the toughest worlds course for more than a decade. The quadruple time trial world champion is using this race merely as training but has tested himself on a number of occasions. His ride in the team time trial was outstanding and he almost won the stage to the end of the world by launching a fierce acceleration on the uphill finishing straight. It was his immense power that brought Tony Martin's stage-winning dreams to an end on stage 6. Finally, he has twice proved his climbing legs by whittling the peloton down to less than 50 riders on some of the hardest Andalusian mountains. The worlds course may not suit the Swiss perfectly but everything suggests that he may repeat his splendid performance from the most recent hilly world championships in Mendrisio.

Uncontrollable sprints

With no Marcel Kittel, Andre Greipel or Mark Cavendish, many of the second-tier sprinters had hoped to exploit the opportunity to rise to grand tour fame like John Degenkolb did it last year. Instead of the emergence of a new super sprinter, the sprint stages of the first week have ended up in pure chaos with no team able to take control.

On paper, Belkin and Garmin had lined up strong sprint teams but both trains have lost power and have only played minor roles in the sprint finales. The former lost Mark Renshaw and Theo Bos prior to the start of the race while the latter dearly misses Koldo Fernandez and Michel Kreder in the hectic final kilometres, the Spaniard having left the race and the Dutchman suffering from the effects of his team time trial crash.

Instead, it has been up to the young Argos-Shimano team to dominate the finishes and while they have done a good job, they have had little chance against world stars like Tony Martin, Zdenek Stybar and Philippe Gilbert. Interestingly, the chaotic circumstances follow on the heels of a recent trends that has seen late attackers foil the sprinters' plans in what would usually have been guaranteed sprints. During the month of August, it happened once in the Tour of Utah, once in the Volta a Portugal, twice in the Tour des Fjords and twice in the Eneco Tour.

The sprinters had looked forward to the first week as their stomping ground but now face an enormous amount of big mountains and steep climbs to potentially get the chance to show their fast legs on three stages. And with the current level of disorganization, it could even happen that they will have to wait all the way to Madrid to finally get a chance to go for glory.