The funny thing about building a business -- or building a career, or building great relationships, or basically doing anything -- is that we typically know what to do. The hard thing is actually doing it, day after day after day.

The problem isn't knowledge. The problem is willpower.

Hold that thought.

Last year a friend wanted to get in better shape, so he embarked on the Hard 75 Challenge.

If you aren't familiar, Hard 75 involves following a diet (you get to pick the diet), working out twice a day for 45 minutes each session (one workout has to be outdoors), drinking a gallon of water, reading (not listening to) 10 pages of a nonfiction personal development book, and taking a picture of yourself. Every day. For 75 straight days.

Fail to complete any of the above on any given day? Start over.

In many ways, Hard 75 is similar to a diet. (In fact, it includes a diet.) As anyone who has tried knows, following a specific diet -- keto, Mediterranean, low-carb, Atkins, whatever -- is hard. Temptation. Availability. (Try staying keto when you're on the road and it's 11 p.m. and the only place open is a Taco Bell.) Consistently making the right choices is hard.

The same is true for exercising outdoors. It's hard to force yourself to go for a run when your day got away from you and it's 8 p.m. and raining and 35 degrees. If you can pull off the Hard 75, that's awesome.

But it's really hard.

And it was really hard for my friend.

He started, got disappointed, summoned up the determination to start over, got disappointed, forced himself to start over... while he got in a little better shape, he didn't make the progress he hoped for. 

Then he took a different approach. Instead of following a strict diet, he just created a few rules. He wanted to eat healthier, so he cut out all "white" foods (breads, white rice, potatoes, crackers, added sugar). When he went out to eat, he avoided failing to find the "right" food by just choosing the healthiest option available. (At Taco Bell, maybe that's the "fresco style" burrito with chicken.) 

And instead of following a specific exercise program, he just decided that he would always work out for at least 20 minutes every day. Most of the time he did longer workouts, but in a pinch he just needed to do 20 minutes of something. Situps, push-ups, and burpees in a hotel room. A light jog in the morning. Hustling up and down steps at the airport during a long layover.

While his workouts were almost always more extensive, still: The only rule he had for himself was that he would work out for at least 20 minutes a day.  That way he never "failed," never got disappointed... and never felt like he had to start over. As long as he got his 20, he was good.

The same approach applies to business. Say you want to spend more time with your employees. Don't create a complicated schedule; just make it a rule that whenever you run into an employee in the hallway, you'll stop and chat for a moment. Some of those chats will lead to longer conversations. Some won't. Either way, you'll come a lot closer to accomplishing your goal.

Or say you want to build a stronger network. Make it a rule that you'll send a note of praise, or encouragement, or advice, or something helpful and positive to one person -- someone you know, or someone you don't know -- every day before you begin your work day. Do that, and you'll naturally make new connections, and build stronger ones.

In my case, I decided I needed to drink more water and less soda. So I decided I would always drink water with meals. Within a couple days, that habit became automatic.

Bottom line? Diets suck. Having to rely on willpower sucks even more.

Rules, on the other hand, are easy.

And great, especially when those rules help take you to the place you someday want to be.