I think a better way of thinking of it is if you work hard now you'll be able to relax/things will be easier later on. I don't think it's saying suffering won't happen at all, but spacing it out maybe would lessen it to an unnoticeable degree, or it's nice to get things out of the way.
I have a few examples that come to mind. The first is homework. If you have a lot of homework due is a week let's say, and you put it off until the end, you'll have a miserable time trying to finish it all at the last minute. Or you can just not do it all, and your grade would suffer greatly from the lack of hard work.
A second is in sports or exercise. Anyone who works out will tell you it's hard and usually not fun, especially at the start. It's very tiring and your sore afterward, it's not very pleasant. Then over time it doesn't become easy, but you do start to get better at it and it's not as difficult, even when pushing your hardest. And you're able to see the results. You're healthier, faster, stronger, thinner, whatever. In that respect, you're not suffering in comparison to how you would have had you not done the work, or basically you're glad after the fact you did it. This can seen even more clearly on the sports field, where if you practice hard it really shows against your competition as you get good results. If you slack off, you lose badly and get bad results. Hard work=good results.
A third is in working. If you work hard in school, you can work to get a good job, work hard their and get paid well (if that's what you want). Even not in school, if you do the best you can in your work you can save money over a lifetime, and have a nice retirement, or have many accolades to look back on our life with.
Basically, working hard now is like planting the seeds of rewards you will sow later on. If you don't work hard, your field is going to be barren.
Someone might consider suffering not to have the latest Ipad or someone else might really be suffering from lack of food...
