Like most things in life, you get as much from training as you put into it. Work hard, get hard. Goof off, stay soft.

Unlike many things, though, it’s fairly easy to reach the point of diminishing returns with exercise, and the penalties of exceeding this threshold (referred to as “overreaching“) can be particularly punishing.

Energy levels, mood, and performance tumble, sleep suffers, and soreness soars, and then the twist of the knife: For all your trouble, you don’t even get marginally better results. Instead, you get progressively worse outcomes.

A good example of this is a study conducted by scientists at the University of Sydney on German Volume Training, which involves doing 10 sets of 10 reps of each exercise in your workout. 

The researchers found that the subjects doing German Volume Training actually gained less muscle and strength than the subjects following a lower-volume routine of 5 sets of 10 reps per exercise. 

What’s more, training is just one type of stress that our body must recover from, and other sources of strain—work, finances, relationships, etc.—also limit how much we can demand of our body in the gym.

So, how can you know when you’re overreaching and need to do some “overresting” instead? Here are a few reliable signs:

1. Your once-enjoyable workouts are now a bear.

Your training weights have fallen, your stamina has declined, and your enthusiasm has disappeared. Every workout feels like trying to go for a walk with a feral 220-pound dog.

2. You often feel “tired and wired.”

Despite feeling drained all day, you feel restless at night. And so you sleep like a toddler on bath salts. 

3. You have unusual aches and pains.

And for no apparent reason. And they slowly get worse. And multiply. Until damn near everything seems to hurt all of the time.

4. You’re training hard every day of the week.

I’ve yet to meet someone who can train or play hard seven days per week without folding up. Including even elite athletes on powerful cocktails of PEDs. No matter who you are, “no days off” eventually becomes “no can do.”

So, listen to your body, recognize its limits, and slow down now and then before the wheels start to fall off.