Is discipline more important than motivation for working out?

Yes, discipline matters more, because motivation is too unreliable to build a routine on. But I'd define discipline differently from how most people do. It isn't gritting your teeth every morning. It's setting things up so you rarely have to.

Motivation is a feeling, and feelings don't show up on schedule. You'll have weeks where you can't wait to train and weeks where the idea is miserable. If your workouts only happen in the first kind of week, you'll train maybe half the time.

Where motivation does help

Motivation is great at one thing: starting. A new goal, a new program or a deadline gives you a burst of energy, and you should use it. Sign up for the class, buy the program, tell a friend, plan the next four weeks. Use the good mood to lock in decisions you'll be glad you made when the mood is gone.

What discipline actually looks like

When people who train consistently talk about discipline, they're usually describing boring structure:

• Workouts at set times, treated like appointments
• Gym clothes packed the night before
• A minimum session for bad days (20 minutes counts)
• One simple rule, like "no more than one missed day in a row"
• An outside reason to show up. A League of Fitness match is decided once the day is over, so there's a deadline and an opponent, and a short session still counts.

None of that takes much willpower. It takes a few minutes of planning when you're calm so you aren't negotiating with yourself when you're tired.

The order matters

Here's a pattern I think is true for most people. You start with motivation. Somewhere in weeks 3 to 6 it fades. If you've built the structure by then, you keep going on routine. If you haven't, you stop. Then a few weeks later motivation comes back and the cycle repeats.

Finishing a session also generates motivation, which is the part people miss. You usually feel better after than before, and that is what makes the next one easier. So you don't have to wait to feel like it. You can start anyway and let the feeling catch up.

If you're stuck

Don't try to become a more disciplined person in general. Pick one thing to make automatic: the time, the place or the minimum session. Fix that, and the rest gets easier. If skipping is the main problem, this page on how to stop skipping workouts goes into specifics.