Inspirational quotes can help keep participants motivated and entertained.  They are also a good way to liven up your weekly messages to your team.

"There are as many reasons for running as there are days in the year, years in my life. But I run because I am an animal and a child, and artist and a saint. So, too, are you. Find your own play, your own self-renewing compulsion, and you will become the person you were meant to be."
“Everyone is an athlete.  But some of us are in training, and some of us are not.”
                                                Dr. George Sheehan
                                                Author, cardiologist, columnist, runner

“A newspaper wrote that I was too old.  It made me so mad that I went out and won four gold medals.”
                                                Fanny Blankers-Koen
                                                Sprinter representing the Netherlands in the 1948

Olympics
"A lot of people run a race to se who's the fastest. I run to see who has the most guts."
                                                Steve Prefontaine
                                                Olympian 5K great

"We rejoice in our sufferings, because we know that suffering produces perseverance; perseverance, character; character, hope. And hope does not disappoint us."
                                                Romans, 5:3-5

"Mind is everything; muscles, mere pieces of rubber. All that I am, I am because of my mind."
                                                -Paavo Nurmi
                                     Nine-time Olympic Gold medal runner

“No one ever drowned in their own sweat.”anonymous

"Bid me run, and I will strive with things impossible."
                                                Shakespeare, in Julius Caesar

"Our greatest glory is not in never falling, but in rising every time we fall."
                                                Confucius

"The will to win is not nearly so important as the will to prepare."
                                                Juma Ikangaa
                                                New York City Marathon champion

"Only those who risk going too far can possibly find out how far they can go."
                                                T.S. Eliot

"Only those who dare to fail greatly can ever achieve greatly."
                                                Robert F. Kennedy

"We seek to go to the moon and do other things. Not because they are easy, but because they are hard."
                                                John F. Kennedy

"I believe anyone can conquer fear by doing the things they fear to do, provided they keep doing them until they get a record of successful experiences behind them . . . you must do the thing you think you cannot do.”
                                                Eleanor Roosevelt

"I hated every minute of training, but I said, 'Don't quit. Suffer now and live the rest of your life a champion."
                                                Muhammad Ali

"If you think you can, or, if you think you can't, you're right."
                                                Henry Ford

"Fall seven times, stand up eight."
                                                Japanese proverb

"Security is mostly a superstition. It does not exist in nature, nor do children of human kind as a whole experience it. Avoiding danger is no safer in the long run than outright exposure. Life is either a daring adventure, or it is nothing at all."
                                                Helen Keller

A goal is nothing but a dream with a deadline.
                                                Anonymous

“The credit belongs to those who are actually in the arena, who strive valiantly; who know the great enthusiasms. The great devotions, and spend themselves in a worthy cause; who, at best, know the triumph of high achievement; and who, at the worst, if they fail, fail while daring greatly, so that their place shall never be with those cold and timid souls who know neither victory nor defeat.”
                                                Theodore Roosevelt

Our team motto:
"Don't tell your body what it can't do; let it tell you what it CAN do." And from six-time Tour de France winner Lance Armstrong:

While winning his third straight Tour de France: "It's not easy.  You hear a lot of comments about, 'He makes it look easy,' or 'His face shows no effort.'  Come look at my face in January when I'm trail-running on my property in Austin, Texas, and I'm hurting like a dog.  It's an ugly face.  I'd rather have the face then and feel good here.  It's called sacrifice."
                       
“I take nothing for granted. I now have only good days or great days.”

“Cancer is my secret because none of my rivals has been that close to death and it makes you look at the world in a different light and that is a huge advantage.”

“This is my body. And I can do whatever I want to it. I can push it. Study it. Tweak it. Listen to it. Everybody wants to know what I'm on. What am I on? I'm on my bike busting my ass six hours a day. What are you on?”

“To be afraid is a priceless education.” 

"Jogging is very beneficial. It's good for your legs and your feet. It's also very good for the ground. It makes it feel needed."
                                                Charles Schulz, Peanuts

“I run because I love it, I run because it makes me happy, I run because it’s good for me and I’m going to run until I die.”
                                                Willie Gault
                                                Retired NFL receiver turned sprinter

“You have to have absolute arrogance to think you can run a mile faster than anyone who’s ever lived; and then you have to have the absolute humility to actually do it.”
                                                Herb Elliot, 1960 Olympic 1500m gold medalist & world record holder in the mile.  Former Boston champ Kenny Moore (the last American to win Boston), explained that this means balancing the arrogance of ambition with the humility of training.