Does sleep apnea hurt your muscles?

Short answer

It worked against muscle, but not through testosterone. People with sleep apnea had low muscle 1.85 times as often, and 12 weeks of treatment that keeps the airway open added 1.5 kg more lean mass. Testosterone did not change with treatment.

Does sleep apnea hurt your muscles?
'Choking at night → less testosterone → less muscle': is it true?
People say that heavy snoring with pauses in breathing during sleep (sleep apnea) lowers testosterone and costs you muscle. We checked step by step: is muscle really lower, is testosterone the reason, and does treatment change anything.
Do people with sleep apnea have less muscle?
Low muscle was 1.85 times as common
An analysis of 13,331 people found that those with sleep apnea had low muscle mass plus low strength (sarcopenia) 1.85 times as often. In studies that measured breathing pauses with a machine, it was 2.78 times. All 8 studies looked at one point in time, so the next cards check the cause separately.
Is testosterone the culprit?
Levels were lower with sleep apnea
An analysis that pooled 24 studies found that 1,268 men with sleep apnea had lower testosterone than those without it. Women showed no difference. The size of the gap varied a lot with age, body weight and how it was measured.
Does opening the airway raise testosterone?
It did not
An analysis of 388 people treated with a machine that blows air to keep the airway open during sleep (CPAP) found no change in testosterone. When 70 people stopped CPAP for 2 weeks, testosterone also stayed the same. The 'testosterone → muscle' link breaks here.
But treatment added lean mass
5 kg more lean mass in 12 weeks
In a trial that randomly split 52 people, those who used CPAP for 12 weeks gained 1.5 kg more lean mass (muscle and everything except fat) than those who did not. Fat showed no difference. A growth-related hormone (IGF-1) went up and the stress hormone cortisol went down.
The other way round, exercise reduced sleep apnea
8 weeks of strength training cut 21 pauses per hour
An analysis that pooled 526 people found that aerobic and strength training cut breathing pauses during sleep by 7.08 per hour. In a trial where 25 people did strength training 3 times a week for 8 weeks, pauses fell by 21.0 per hour, while the stretching-only group rose by 3.5.
Summary: sleep apnea worked against muscle
The link was not testosterone
People with sleep apnea had low muscle 1.85 times as often, and opening the airway with CPAP added 1.5 kg more lean mass in 12 weeks. Testosterone was the same before and after treatment. Strength training even reduced breathing pauses, so keeping up your training is the way to go.