<p>Save and invest sensibly, and you&rsquo;ll eventually reach a point where your investment gains exceed what you sock away for retirement. Here&rsquo;s how to get there.</p>

- Walter Updegrave

YOUR RETIREMENT ACCOUNT is made up of two parts: the contributions you diligently make throughout your career and the investment returns those contributions earn for you.

Not surprisingly, your contributions—and those of your employer, if you receive company matches in your 401(k) account—initially dwarf what your investments earn in the market. But if you save regularly and invest sensibly, you will eventually hit a crossover point where your investment gains exceed the contributions you make to your accounts.

At that point, you’ll be in the sweet position of sitting back and watching your investments effectively do the bulk of your savings for you.

This is what all retirement savers should be aiming for. And that’s why a balanced, disciplined long-term approach that will successfully get you to this crossover point beats a strategy that swings for the fences and takes undue short-term risks.

HOW LONG BEFORE YOUR INVESTMENTS DO THE HEAVY LIFTING?

Here’s how this works: Let’s say you earn $45,000 a year, receive 2% annual raises, and contribute 10% of your paycheck each month into a 401(k), where your investments earn a 6% annual return.

When you start out, your investments earn a mere pittance compared with the amount you’re socking away. That first month, in this example, you contribute $375 to your account, which racks up less than $2 in investment gains for the month. Even after you’ve socked away a full year of savings (or $4,500), your inv