If you don't keep your brain sharp as you age, you can develop mental illnesses more quickly.
to stay mentally active
The pilot practiced several touch and go landings during training.
an uncertain situation
I've been worried about Rebecca; she's been burning the midnight oil trying to finish her doctorate.
Stay up late working or studying (which can negatively impact health)
Sarah's been feeling pretty under the weather, so she's book a doctor's appointment.
Feeling sick or unwell.
Have you seen Josh? He's been working out! He looks as fit as a fiddle!
In excellent health.
I don't think I can compete nowadays due to the fact that I run out of steam quickly.
Lose energy or motivation
My mom is very scared of going under the knife, she'll avoid it at all costs.
To have surgery.
Mary had been ill for some time. It's nice to see her back on her feet
To be well again after a sickness
I need to get out of town for a few days so I can recharge my batteries.
to rest for a period of time
Don't be so down, you're so young and in the pink of health!
In very good health.
Have you heard about Cindy? She's finally on the mend from the accident last month!
Recovering from an illness or injury
These kids today are so full of beans! They won't sit still for a second!
Energetic and lively.
A lot of people nowadays are signing up for the gym, trying to keep in shape.
to stay physically healthy
I don't know how marathon participants don't just throw in the towel.
Give up or stop trying, often due to exhaustion.