I was reading about 19th century philosopher Schopenhauer recently and was struck by his pessimism.

He said "life swings like a pendulum to and fro between pain and boredom, and these two are in fact its ultimate constituents."

He wouldn't do well on Instagram, would he?

But he's not far from the truth.

There's a fine balance to be struck between the discomfort you must endure to change and grow, the suffering created by wanting what you don't have, and the emptiness of aiming at nothing, or getting what you want and being unfulfilled.

I've worked with many people who were unhappy with their bodies, careers, and relationships. They were stuck in a cycle of pendulum swings.

It doesn't have to be that way.

If you find yourself stuck, there are two key principles that will help you break out:

1. Accepting what's outside your control, directing your efforts towards what's within your control

Contrast this with the movement towards body acceptance and intuitive eating, which says you'll be happy if you relinquish control over what you eat and seek to change how other people think about your body.

I don't buy it.

Acceptance only works once you've looked within and figured out who you really are.

It's not about how you look, it's about your character and your thinking.

You're always presented with opportunities to make better decisions and to practise exerting control instead of relinquishing it.

When you habitually relinquish control, you develop learned helplessness, like an animal stuck in a zoo enclosure.

Resist this by focusing on the things within your control and exercising your willpower regularly.

2. Working on projects with no endpoint

When you are process oriented you eliminate the frustration of trying to reach a terminal state, - success or failure, - because the process itself is limitless.

The problem is that so much of fitness is concerned with superficial metrics of success, like how many calories you burn, or how many sets and reps you're supposed to do.

If you can engage fully in a movement, creating total focus on the muscles you're trying to work, and execute the highest quality repetitions until you fatigue those muscles, you will get better results.

Turn off the music, ditch the stimulants, and forget about what internet science gurus say is the correct amount of work to do.

Learn to cultivate your internal environment, like a gardener of your own thoughts.

Work tirelessly on improving your decision making process rather than focusing on the quality of individual decisions.