Michael Phelps’ return to the pool

Michael Phelps reacts after winning the 200-meter individual medley at the U.S. winter national championships Dec. 3.

Michael Phelps looks at the scoreboard after winning the 200-meter individual medley at the U.S. winter national championships Dec. 3.

Michael Phelps swims in the 200-meter individual medley at the U.S. winter national championships Dec. 3.

Michael Phelps celebrates after winning the 100-meter butterfly final.

Michael Phelps competes in the 100-meter butterfly final.

Michael Phelps celebrates on the podium after winning the 100-meter butterfly final.

Michael Phelps talks with the media after he competed in the preliminary round of the 100-meter butterfly.

Michael Phelps celebrates his win in the finals of the 200-meter butterfly.

Michael Phelps competes in the finals of the 200-meter butterfly.

Michael Phelps celebrates his win in the 200-meter butterfly.

Michael Phelps celebrates after receiving his medal for his first-place finish in the finals of the 200-meter butterfly.

Michael Phelps practices for the nationals at the Northside Swim Center on Aug. 5.

In 2014, Phelps annoucned he would come back from retirement. Here he is in 2015 speaking to the media after a morning practice.

Michael Phelps practices for the U.S. nationals Aug. 5.

Michael Phelps speaks to the media after a morning practice for the U.S. nationals Aug. 5.

Michael Phelps swims to victory in the 200 IM at the Arena Pro Swim Series event in Santa Clara, Calif.

Michael Phelps swims Saturday in the men’s 200 meter butterfly at the Arena Pro Swim Series event at the George F. Haines International Swim Center in Santa Clara, Calif.

Michael Phelps wins the men’s 200-meter butterfly in 1:57.62 on Saturday at the Arena Pro Swim Series meet at the George F. Haines International Swim Center in Santa Clara, Calif.

Michael Phelps won the 200 butterfly Saturday for the first time since the 2012 Olympic trials.

MESA, AZ - APRIL 18: Michael Phelps’ fiancee Nicole Johnson (center) smiles during day four of the Arena Pro Swim Series at the Skyline Aquatic Center on April 18, 2015 in Mesa, Arizona. (Photo by Chris Coduto/Getty Images) ORG XMIT: 537309131   (Chris Coduto / Getty Images)

Michael Phelps’ fiancee, Nicole Johnson, looks at a heat sheet Saturday.   (Chris Coduto / Getty Images)

Michael Phelps looks at the scoreboard after winning the 100-meter freestyle final.   (Matt York / Associated Press)

Michael Phelps dives in for the 200-meter individual medley prelims.   (Chris Coduto / Getty Images)

Michael Phelps talks with Conor Dwyer before the 200-meter individual medley prelims.   (Chris Coduto / Getty Images)

Michael Phelps competes in the 100-meter butterfly final.   (Matt York / Associated Press)

Michael Phelps smiles after finishing first in the 100-meter butterfly final.   (Matt York / Associated Press)

Ryan Lochte, left, congratulates Michael Phelps after Phelps won the 100-meter butterfly final.   (Matt York / Associated Press)

Michael Phelps adjusts his goggles before competing in the 100-meter butterfly final.   (Matt York / Associated Press)

Michael Phelps dives in during the 4x100-meter freestyle relay final at the Pan Pacific Championships.  (PATRICK HAMILTON / AFP/Getty Images)

Michael Phelps looks on after winning the 100-meter butterfly final at the Pan Pacific Championships.  (Chris Hyde / Getty Images)

Ryan Lochte, left, and first-place Michael Phelps smile during the medal ceremony after the 100-meter butterfly final at the Pan Pacific Championships.  (PATRICK HAMILTON / AFP/Getty Images)

Michael Phelps is all smiles after the United States won the 4x200-meter freestyle relay final at the Pan Pacific Championships.  (PATRICK HAMILTON / AFP/Getty Images)

Matt Mclean, Ryan Lochte, Michael Phelps and Coner Dwyer of the United States wear their gold medals proudly after winning the 4x200-meter freestyle relay final at the Pan Pacific Championships.  (Matt Roberts / Getty Images)

Michael Phelps swims in his 100-meter butterfly heat at the Pan Pacific Championships.  (Chris Hyde / Getty Images)

Michael Phelps collects himself after his 100-meter butterfly heat at the Pan Pacific Championships.  (PATRICK HAMILTON / AFP/Getty Images)

Michael Phelps pokes his head out of the water after finishing his 100-meter butterfly heat at the Pan Pacific Championships.  (PATRICK HAMILTON / AFP/Getty Images)

Michael Phelps congratulates Matt Grevers on his win in the 100-meter backstroke final at the 2014 Phillips 66 National Championships.  (Harry How / Getty Images)

Michael Phelps leaves the pool after his race in the 100 backstroke final.  (Harry How / Getty Images)

Michael Phelps moves along in the 100 backstroke final.  (Harry How / Getty Images)

Michael Phelps swims in the warm-up pool.  (Ezra Shaw / Getty Images)

Michael Phelps dives in for the start of his heat in the 200 free.  (Ezra Shaw / Getty Images)