TRUCKEE, Calif. - One thing investors try to do is determine future trends to see what companies will be in a position to capitalize on them. Demographically, one thing for sure is that people are living longer and living healthier. Individuals who retire at the normal retirement age of 65 can expect to live 20 years or more.The long life expectancy means that retirees need to plan carefully for their retirement income. Health care costs are an important consideration when doing retirement planning. One way to help control health care costs is through a health and fitness program.As more and more people become aware of the importance of maintaining a healthy lifestyle, health and fitness stocks have performed well over the last few years. Health and fitness stocks can be broken down into a few different industries.One is in gyms and fitness centers and the leader there is Lifetime Fitness; they are almost a $2 billion company and have more than 105 locations nationwide.Another area that has done well is vitamins and supplements. The leader there is General Nutrition Centers; they are a $4 billion company with that has more than 8,000 locations. Vitamin Shoppes is another; they have a market cap of about $1.5 billion and about 580 stores.Herbalife is another player in the nutrition area. Their stock has been in the news a lot lately and as a consequence could be subject to some short term volatility. Hedge fund manager Bill Ackman has called it a Ponzi scheme and is shorting the stock. Billionaire Carl Icahn has invested in the stock, and has people from his organization on the board.I'm not sure what will end up happening here, but when you have two billionaires in a battle like this, it may make sense to avoid this one until the dust settles.Sports equipment and apparel has seen strong sales growth in the last few years, too. Nike is the big player in this area with a $49 billion market cap and a long story of success. Nike was started by Oregon track coach Bill Bowerman in his garage. The first Nike shoes were made by pouring molten rubber into his wife's waffle iron to make the soles. Not sure if his wife was too happy about that. Under Armour is another strong one in the sports apparel business.Looking ahead, I think it's a pretty good bet that people will live longer and healthier and that health and fitness stocks should have a bright future.Kenneth Roberts is a Truckee based Registered Investment Advisor. Information on his money management service can be found at his blog at www.sellacalloption.com or by calling 775-657-8065. Past performance does not guarantee future results. Consult your financial adviser before purchasing any security.