He loves playing football, riding his bike and swimming.
But his doting parents know that Joe is not like other boys – and that he will be in a wheelchair before his 10th birthday.
The bubbly youngster may never reach adulthood because he suffers from Duchenne Muscular Dystrophy, a muscle-wasting condition which means he will get weaker year by year.
His parents Stewart and Annette Rush have launched a massive charity fundraiser to help find a cure for the disease, called Duchenne, which affects only one in 3,000 boys worldwide. It is even rarer among girls.
'Ten miles for Joe', which more than 100 people are already sponsoring to the tune of £5,000, will see Mr Rush swim 10 miles non-stop at his local pool.
The motto for the day, in aid of the charity Action Duchenne, is Using Our Muscles To Save Theirs.
Mr Rush (36), who lives in Petersfield, said: "We didn't realise there was a problem with Joe until last year.
"His teacher came to us and asked if Joe was okay because he was falling over all the time and couldn't keep up with the other boys."
A muscle biopsy revealed that Joe's muscles were not normal.
"At first I couldn't really face it,' said Mr Rush. "I built a car for a year. When I finished, I realised I would have to deal with it.
"Joe is weaker than other boys. He can't ride a normal bike because he just hasn't got the strength in his legs."
Joe rides a special light-frame bike and swims every week to keep his muscles as strong as possible.
Mrs Rush (31) said: "The biggest thing for us is raising awareness. When we found out we were horrified.
"The only thing stopping finding a cure is money."
Mr Rush has been training for the event, which will take place at the Taro Leisure Centre's pool in Petersfield on May 24. He has been swimming four hours a night – around 420 lengths.
"They say swimming one mile is the equivalent of running three miles," he said. "So swimming 10 miles is a harder task than running a marathon.
"Cross channel swimmers can lose up to a stone in weight so I will have to make sure I take on plenty of fluids during the swim."
Mr Rush was not a regular swimmer before deciding to take on this task but was inspired to do it by Joe's swimming teacher.
Joe swims to help maintain the flexibility in his muscles and his tutor, Victoria Harris-Driscoll, suggested the idea of a sponsored swim.
Now Mr Rush, who races his Lotus Elise, hopes to raise more than £5,000 for Duchenne's thanks to generous family, friends and fellow Lotus drivers.
"I originally set my target at £1,000 but when I posted that on the Elise message board I subscribe to I got that in the first day," he said.
"Now I have set the target at £5,000 and I currently have around £4,700."
Joe will be sounding the starting horn.
"I am doing all this for Joe," said Mr Rush. "Every day we have with him is precious for us."
To sponsor Stewart, log on to his website: www.justgiv ing.com/10milesforjoe and make a donation.