Modern football asks a lot from players. The demands of the game are such that maintaining peak physical condition becomes a necessity in order to survive at the highest level.With clubs involved in various competitions, as well as national team football to consider as well, players have to be at their sharpest, mentally and physically, in order to cope with the flurry of high-intensity games.From a properly-tailored diet to various technological innovations used by clubs, players are carefully taken care of. Despite all this, injuries occur.Some players, however, manage to be everpresent for their clubs and countries. We look at the:5 fittest players in world football at the moment#5 Zlatan Ibrahimovic (AC Milan)Zlatan Ibrahimovic before an AC Milan gameOne of the greatest strikers of the modern generation, Zlatan Ibrahimovic's longevity at the highest level has astounded many fans and critics.The 39-year old has enjoyed successful spells at top clubs like Ajax, Inter Milan, AC Milan, Paris Saint-Germain and Manchester United. After a short stint with LA Galaxy in the MLS, the Sweden international joined AC Milan in January 2020, and has been their main attacker since then.Reason, strength and heart. 👏 🔥That’s how you win trophies. 🏆 @Ibra_official #SerieATIM #WeAreCalcio pic.twitter.com/AT5xn8ff46— Lega Serie A (@SerieA_EN) March 30, 2021Ibrahimovic has made 44 appearances in all competitions for AC Milan since rejoining them, scoring 28 goals. The striker is set to feature in the Euros this summer for Sweden, having reversed his retirement decision.#4 Andrew Robertson (Liverpool)Andrew Robertson in action for LiverpoolLiverpool have been extremely unlucky with injuries this season, but one player who has featured consistently is Andrew Robertson.When Liverpool signed Robertson from Hull City in 2017 for £8 million, eyebrows were raised. Nearly four seasons later, the Scotland international is considered to be one of the best left-backs in the league and one of the most consistent performers in Liverpool's back-four.Andrew Robertson has covered a total 4268 metres towards the opponents goal this season. ENGINE.#ARSLIV #EPL #PremierLeague— Professor Scarn (@ProfessorScarn) April 3, 2021The 27-year old has made 40 appearances in all competitions this season, often acting as the senior figure in Liverpool's defense in the absence of Virgil van Dijk. He has made 167 appearances in all competitions for Liverpool since his debut.Also Read: 5 most valuable players in the Premier League this season