Phelps competed at the US National Championships and won gold in the 100m butterfly, 200m butterfly and 200m individual medley - swimming the fastest time in the world in each of these events for 2015.
At the US trials for Rio he won the same three, and became the first American male swimmer to qualify for a fifth Olympics. He is still a great sportsman, and so starts us off No 10.
9. MO FARAH
Farah wanted to go to Rio 2016 after running the men's 5,000m in less than 13 minutes. When the pace started to slow with five laps to go, he set off solo, and finished in 12 minutes, 59.29 seconds.
That was at the Anniversary Games in London this week and his fastest time since June 2012. His legs are older but Farah still feels fresh.
The 33-year-old ran the fastest 5,000m in the world this year and said: 'I've never felt better.' We have him at No 9 as he prepares to try to prove himself in the Olympics this summer.
8. LEWIS HAMILTON
Hamilton cruised to the Formula One championship last year - his second successive world title - and has five wins to his name this season, leading Mercedes team-mate Nico Rosberg in the drivers' championship.
The Brit has had his fair share of bad luck: collision with Valtteri Bottas in Bahrain, zero water pressure for the last 16 laps in Russia, another collision in Spain, this time with Rosberg.
Yet a home win in the British Grand Prix in between triumphs in Austria and Hungary got him back to business, and Hamilton is on top yet again. We have him at No 8 - for now.
7. LEBRON JAMES AND STEPH CURRY
Two greats, and too tough to split. James was left in tears in June as he and the Cleveland Cavaliers won their first NBA title by overcoming Curry and the Golden State Warriors.
The Warriors were the defending champions but Curry could not add to his title win from the year before, and James delivered on a promise from two years ago to bring a championship to Ohio.
Curry was named the NBA's MVP for the second successive year too, and so we've decided to call this a tie.
6. GENNADY GOLOVKIN
A beast of a boxer. A middleweight machine.
Golovkin beat Dominic Wade in April - 30 seconds before the end of the second round - and it was his 22nd straight knockout to take his winning run to 35 fights.
It is not hard to see why he is being described as the most dangerous boxer in the world at the moment. Golovkin, 34, is ruthless and Britain's Kell Brook is next at London's O2 Arena.
5. CHRIS FROOME
The sight of a bike-less Froome running the final climb will go down in history, and so will the 31-year-old himself.
Froome became Britain's first three-time winner of the Tour de France this week and is the first man to successfully defend his title in more than 20 years.
He won in 2013 and 2015 too, and Sir Bradley Wiggins described Froome as the best Tour de France rider of the modern era. All that is why we've placed him at No 5.
4. CRISTIANO RONADO AND LIONEL MESSI
Yes, another tie. After all, how do you split these two? It's the greatest debate in football, and you can only wonder how much they would cost if Paul Pogba is worth £100m.
What works against them is that they play in a team game and have team-mates to help them, but that only counts against them marginally in Sportsmail's list here.
Some will say Ronaldo is a nose ahead of Messi following Portugal's win at the European Championship and his winning penalty in the Champions League final.
Messi, though, won La Liga as Barcelona beat Real Madrid to the title and the Argentina star only lost out in the Copa America final to Chile on penalties.
3. SERENA WILLIAMS
The Queen of Centre Court lived up to her name at Wimbledon as Williams won two titles in the same day.
First, Williams beat Angelique Kerber to win her seventh SW19 and 22nd Grand Slam title as she showed why, at the age of 34, she is still a truly great sportswoman.
Then later in the day, after fulfilling her media duties, she won the women's doubles with her sister, Venus, as they beat Timea Babos and Yaroslavl Shvedova. That's why we have the American at No 3.
2. USAIN BOLT
Bolt dominated the 200m at the Anniversary Games in London's Olympic Stadium as a warm-up to this summer and you get the feeling he is ready to take Rio 2016 by storm.
The six-time Olympic champion, who won gold in both the 100m and 200m at London 2012 and Beijing 2008, is preparing to defend his titles.
Bolt also won the 100m and 200m at the World Championships last year, just as his harshest critics were preparing his professional obituaries. Still the most superb sprinter in history.
1. NOVAK DJOKOVIC
Four Grand Slam wins in succession - 2015 Wimbledon, 2015 US Open, 2016 Australian Open, 2016 French Open - ended at SW16 but no one deserves top spot more than Djokovic.
His third-round loss at Wimbledon to American Sam Querrey was his earliest exit in a major tournament since 2009 but it just goes to show his dominance since.
The 2016 French Open saw him become the third player in history to hold all four Grand Slam titles at the same time. That's why he is world No 1 in tennis, and our No 1 here.
