For athletes, sport isn't just a job, it's a calling. It is only with passion and perseverance that any athlete succeeds. To build a career out of playing sports, you need to be particularly passionate. The difficulty is to keep things in perspective. It's great when your training is going well and you are winning matches, but what happens if you're injured or need to retire for health reasons?

Those athletes who do not plan for their career after sports often find life really tough. With some careful planning, however, it is possible to build a successful business out of your sports career.

As a professional basketball player, I reached the height of my fame during the 1988 Seoul Summer Olympics when I was just 19 years old. Peaking so early brought me great fame and fortune but it wasn't enough to set me up for life. If I was going to have a life after sports, I knew I needed to carefully manage my career from day one.

So how did I do it? Here are my 5 tips to help you build a business from your sports career...

  1. Remember: Athletics is only the first part of your career

Becoming a professional athlete is tough. It's hard to find the time to study, train, find sponsorship and earn money ‒ all while living life. When you finally do break through, it can feel like you've arrived...that this is it!

But it's incredibly important to remember that sport is only the first stage in your lifelong career. Most professional athletes retire in their thirties ‒ it's just too physically demanding to compete professionally beyond that age. And, unlike when you're starting out, there are very few people there to support you in your retirement. It's all down to you.

As such, I highly recommend that you complete your school studies, even if it delays your professional sports career. Without a basic education, it is hard to gain a toehold in society after you retire from sports. A good education will also help you navigate the world of sports better, helping you avoid bad contracts and deals, for example.

It's also important to watch your finances. A lot of athletes start earning good money and blow it all on fast cars and holidays. These expenses may be fun, but they won't help when your sports career is over. Cars devalue rapidly and holidays become distant memories. So, make sure you put some of your money to good use.

  1. Invest your new income wisely

Rather than buying a fancy new Ferrari, a yacht or some other flashy item with your big paycheck, consider what to invest your money in. Property is a good example as it's likely to retain or grow in value over your career.

You could also think about investing your disposable income in businesses. I love technology, for example, so I invested regularly in exciting new technology companies. Not every investment will be a winner, but with some careful financial planning (and probably some expert advice) you can put your money to good use and gain a return on your investment later in life.

  1. Connect with your fans early

Fans are an essential source of support throughout your sports career and afterwards. They will come and see your matches, buy your merchandise, and even provide financial support. For example, GlobaTalent allows athletes to raise money directly from their fans in order to fund those difficult early days without selling out to a bank or big investor.

By engaging your fans at an early stage in your career, you help to build and establish a strong fan base. Not only does this feel amazing but it can seriously help kickstart your career after sports. They will be your first customers, your social media advocates, and your brand ambassadors. Treat them well now and they will return the favour later.

  1. Use image to your advantage

If you are particularly successful in your sports career, it will be extra hard to hold a normal job when you retire. I haven't played professional basketball in many years, yet I am still stopped and asked for photographs and signatures, especially in my native Spain.

As a sports star, it's important for you to represent the sport in a good way, inspiring the next generation to become athletes and demonstrating what good sportsmanship looks like.

However, while this recognition may make it difficult to hold a normal job, it does open-up new avenues for making money, especially in our world of social media. Popularity gives you influence and influence can be commoditised. You can endorse products or services, promote them to your fans, or even use it to set up your own business. How many people have watched George Foreman box compared to the number who own a George Foreman grill?

To make this work, you need to look after your image. Think of your public persona as your business ‒ it needs to have a good reputation and a good standing in order to sell. One way to maintain your image is by engaging your fans on a regular basis and giving back. If fans feel part of your journey, they will come to regard you positively and support every stage of your career ‒ professional or otherwise.

  1. Use your influence for good

As well as using your image and influence to make money, you can also use it to improve the world around you. Say you have 10 million fans. If each contributed just £1 you could build a new mental health unit in a hospital, or pay tuition fees for 33,000 university students.

Whatever philanthropic activity you decide to support, do it with a smile. Magic Johnson hasn't played professional basketball since 1996, yet he is often in the news supporting philanthropic endeavours with a big smile on his face. This positive attitude has endeared him to existing fans as well as making him many new fans, keeping him relevant even after his retirement.

As you can see, developing a successful career in sports involves much more than being a great athlete. You need to see sports as the first step in a lifelong career, planning and saving for later stages in life. When viewed in this way, sport becomes an amazing stepping stone to almost anything else you want to achieve.

With any luck, you'll get some good contracts, some career success, and gain a big following of engaged fans. With these tools at your disposal, you are perfectly positioned to develop a strong career after sports while helping to improve the world around you.

Ferran Martínez is one of the co-founders of GlobaTalent,He is a former pro basketball player for FC Barcelona and the Spanish National Team