You’ve heard it before: investing in stocks is like running a marathon, not a sprint. But what does this mean, and how should it be applied in the real world of finance?

This past weekend I attended the Coastwise Mile, an annual running event with races from a hundred yards to a several miles. There’s even a race for dogs (and their owners J).

For the short races, the participants sprinted off the starting line as fast as possible and, while they were certainly winded, everyone made it to the finish line with no problem. The longer races, on the other hand, were a different matter. The people who commenced the run at a reasonable pace seemed to finish strong. The ones who took off with a vengeance struggled about half way through the viewer friendly course with multiple laps. Because they had not matched their exertion with the distance, they were less than successful in achieving their desired outcome.

Let’s apply this to the stock market. Investors, either independently, or with an advisor, usually do a pretty good job up front of lining up their investments with their time horizon. Need money this year? Let’s keep that cash safe in a bank account and not subject it to near-term stock market fluctuations. Have some retirement money for 20 year hence? No problem – toss that into a well diversified IRA and we’re good to go.

The problem is, to complete the analogy, that the stock market running course, as it were, never stays flat, let alone in one place. It is constantly changing. Sometimes, at the beginning of what is to be a 10 year ‘race’ (for the purposes of this comparison let’s say 1 mile equals 1 year), the otherwise flat course turns into a mountain with hurricane like head winds. Think the first quarter of 2009 when the market had the worst first two months of the year in history. If you started an investment program at the beginning of 2009 you could have easily been swept off course by the storm – no matter how much intellectually and emotionally you were committed to the long run when you set up the program.I hear people regularly say, “Well, we are only up 3% in the first 6 months and my goal was to be up 8% per year on average for 5 years so we are behind schedule.”

I have to remind them in that case that the market was down 5 or 6%, so in reality they are likely ahead of, not behind, schedule. It would be akin to your hoping to average 8 minutes per mile for 10 years – only the first mile of the course is one of those up-hill types where of course your time will be slower, but not to worry as there are some downhill miles ahead that will more than make up for the tough initial terrain.

Bottom line: understand that even in sunny San Diego, like we experienced last week, it storms once in a while. Don’t let that change your long-term plans, investing or otherwise. When it comes to stocks, truly be in it for the long run. That is not to say you should not or cannot take advantage of near-term volatility along the way; smart professional money managers do this all the time. But don’t let a few bumps in the road lead you down the slippery slope of thinking ‘this doesn’t work’ and then pulling money out at just the wrong time.

Think of all those investors who said, “I can’t take the pain anymore” in March of 2009, only to see the market rally 70% in the next 9 months. You think running is painful? Ouch.