Some things just take prolonged hard work, and results may not be evident for a long time. If you decide to get in shape, for example, you may have to put in many months in the gym while also changing your eating habits before you notice a difference in your appearance.

The hard work and pain are daunting even before the moment you start, and you have to endure them without an obvious payoff until you see results. Saving for retirement is like that, too. You have to do the right thing for a really long time before you see the desired payoff, which makes it easier for people to put off taking the right steps.

Perhaps that's why 62% of Americans said they need to "catch up on their retirement savings," according to a new survey from TD Ameritrade conducted by Harris Poll.

Two fingers depositing money in a piggy bank.

Saving for retirement requires long-term discipline. Image source: Getty Images.

Where does the money go?

It's hard to save for retirement when you're facing more immediate needs. It takes real discipline to put off buying something you want now in favor of setting aside money for something in the distant future.

Poor impulse control is only part of the story. Survey respondents cited a number of reasons why they haven't saved enough for their retirements (respondents were allowed to name more than one answer):

  • 28% blamed having to support family members financially
  • 28% cited not having enough income
  • 28% say their housing costs are too high
  • 27% named healthcare costs
  • 24% said they were behind because they started too late
  • 18% blamed non-discretionary spending
  • 14% claimed that unstable markets have caused them to fall behind
  • 13% said their workplace doesn't offer access to retirement plans
  • 12% said student loan debt kept them from saving for retirement

Those are a lot of different reasons, but none of them will sound very good to a person who hits retirement age and has to keep working or vastly downgrade their lifestyle. It also doesn't explain why only 20% of those surveyed said they have maxed out their 401(k)s.

Americans are, however, hopeful -- even when logic and numbers tell them not to be. Over two-thirds (68%) of those surveyed believe they'll be able to catch up, and 64% expect to be able to retire by 65.

In addition, 87% of respondents said they would be willing to make trade-offs -- like packing a lunch instead of buying one or cutting back on vacations -- in order to catch up. What people say, however, isn't necessarily what they do, because thinking you're willing to make sacrifices and actually making them are two different things.

Take action now

There's nothing you can do to change how you acted in the past. What you can do is start making better choices now. That means evaluating how far behind you are and taking some steps. That will generally include finding ways to cut your expenses, setting aside savings in an emergency fund, and then moving on to set up an investment account and making modest deposits regularly. You may not be able to make an immediate plan that gets you all the way to your end goal quickly, but these steps will get you moving in the right direction.

Think of it this way: If you hope to have $1 million saved by 65 but only get to $500,000, you're in a much better position than if you have zero. It's hard to forego short-term pleasure for long-term goals, but if you hope to retire comfortably, that's what you have to do.