Poor Respiration

The character’s lungs have shrunk to a size somewhat smaller than is typical for her size and species, making it difficult for the character to breathe.
Type: Minor negative.
Effect: The character cannot take deep breaths. She can only hold her breath for a number of rounds equal to half her Constitution score (round down) before making saving throws against suffocation. She also suffers a -2 penalty on Fortitude saves against suffocation.
When engaging in strenuous activity (fighting, climbing, running, etc.), she can only maintain the activity for a limited amount of time. After 5 rounds, she must make a Fortitude save every round at the beginning of her turn. The DC starts at 10 and increase by +1 every round. Failing this save means that the character is fatigued (cannot run, and suffers a -2 penalty to Strength and Dexterity). If the character continues the activity after becoming fatigued, she must continue making Fortitude saves. Failing a second save means that the character is now exhausted (can only move at half speed, and suffers a -6 penalty to Strength and Dexterity). If the character still does not cease the strenuous activity, failing a third save results in her falling unconscious for 2d6 rounds. When she wakes up, she is still exhausted.
Exhausted characters with this mutation need 2 hours of complete rest, after which they become fatigued. Fatigued characters need the standard 8 hours of rest to recover.
Biotech: Implant, Graft.