“Run fast/hard, turn left” is jocular running advice that has been printed on many T-shirts. “I thought there were just two things to do: run hard and turn left” was cited in print in 1978. “Run fast, turn left” was cited in print in 1992.
 
“Hit hard, run fast, turn left” is baseball/softball advice.
     
       
Google News Archive
28 September 1978, Ocala (FL) Star-Banner, “It’s A Winning Trip” by Gordon Hanson, pg. 1D, col. 3:
FARGO, N.D. (AP)—Everybody should run a half-marathon—once.
(...)
For months I kept plodding around the YMCA track despite some really outdated training notions. I thought there were just two things to do: run hard and turn left.
   
Google News Archive
1 April 1992, The Spokesman-Review (Spokane, WA), “With Macdonald on track, Cougs have high hopes” by John Blanchette, pg. D1, col. 1:
The convenient theory—convenient in explaining away WSU’s lack of comparable success in other sports—is that the Cougars owe their success to ringers recruited from faraway lands, ready-mades Chaplin and assistant Rick Sloan shoo onto the track with instructions to run fast, turn left and hurry back soon.
   
Google Books
That’s Life in the Big Ten
By Dan Waters
New York, NY: ToExel
1999
Pg. 72:
Regarding the need to pace myself, rather than sprinting full bore at the beginning of a distance race, my dad told me, “A dog that shits fast don’t shit long” The best my coach could do was, “Run fast, turn left.”
 
Google News Archive
7 September 2002, Victoria (TX) Advocate, “Lemons had a line for every occasion” by Gil LaBreton (Fort Worth Star-Telegram), pg. 1C, col. 5:
(University of Texas athletic director DeLoss —ed.) Dodds had been a successful track coach at Kansas State, and Abe (University of Texas basketball coach Abe Lemons—ed.) would still lament, years later, “I got fired by a track coach. I got fired by a guy who all he had to do was tell his players to run fast and turn left.”
(DeLoss fired Lemons in 1982.—ed.)
   
Google Books
Blood, Sweat and Cheers:
Athletes Speak Out
By Rob Ryder
Lincoln, NE: iUniverse
2007
Pg. ?:
My track coach says, “Just run fast and turn left, if something is in your way jump over it and if someone hands you a stick grab it.”
 
Twitter   
Chris Nickinson
‏@chrisnickinson
It’s a great day to be at the track for the guys’ session. Run fast, turn left!
8:49 AM - 7 Mar 2009
 
Twitter 
Leslie Cole
‏@leslie400m
@kid_korrupt yea I’m still tryna figure out plans for the upcoming year also, run fast and turn left is a must!! and OU is still good me!
4:17 PM - 19 Dec 2009
 
Twitter 
HOPKINS X COUNTRY
‏@hopkinscc
14 days until the Royal Track and Field Season Begins. Run Hard, Turn LEFT!
4:02 PM - 1 Mar 2010
 
Twitter
Mysteriously Unnamed
‏@Schum1dt
Hey track stars, run hard and turn left if we win nice job. Back on the bus
11:17 AM - 2 Mar 2010
 
Twitter
Keary Colbert
‏@kearycolbert
@USCJoeyhughes fasho… Ima try to make it. Run hard & turn left!!!! (best track advice somebody gave me. Lol)
4:54 PM - 18 Mar 2011
 
Google Books
Dinner With the Pastor:
And Stay for Dessert
By Joe R. Cannon
Bloomington, IN: iUniverse
2012
Pg. 106:
“Do you know how to win at track?” My answer was “Run fast, turn left, finish first. Yes, I do!”
 
Running Times
Run Fast, Turn Left
Can a nonelite competitive runner chase track dreams?
By Jim Gerweck
June 22, 2012
It’s been said, perhaps with some justification, that track and field in the U.S. is a hide-and-seek event, bubbling up into the consciousness of the public and mainstream media only during an Olympic year, then being relegated to the back pages of the sports section (if it’s lucky) for the intervening three.