Alternative form of no pain, no gain

Synonym of win one's spurs

(medicine, virology) Medical research that alters an organism or disease in a way that increases pathogenesis, transmissibility, or host range.

plural of gain-of-function research

An individual's wealth can easily be lost.

Some people's misfortune is other people's fortune.

Alternative form of what you lose on the swings you gain on the roundabouts

(UK) There are both gains and losses in life; you win some, you lose some.

(bodybuilding) A high-calorie beverage or powdered drink used to bulk up the physique, especially the muscles. Typically, such beverages are very high in sugar content, and need to be drunk in large volumes.

(bodybuilding) A person who has difficulty gaining weight through either diet or exercise.