The drug didn’t make muscles stronger or change how much energy they used during exercise — only how fast they recovered afterward, which points to mitochondria being the target.
Scientific Claim
In obese adults with reduced GH, the association between IGF-I and phosphocreatine recovery was not observed for PCr depletion or maximal voluntary contraction, indicating the effect is specific to mitochondrial recovery kinetics and not muscle strength or energy demand.
Original Statement
“There were no associations between the change in IGF-I with the change in PCr depletion or MVC (P > .10).”
Evidence Quality Assessment
Claim Status
appropriately stated
Study Design Support
Design supports claim
Appropriate Language Strength
association
Can only show association/correlation
Assessment Explanation
The absence of association is reported with statistical values and correctly framed as a null finding. 'Not observed' is appropriate language.
Evidence from Studies
Supporting (1)
The effects of tesamorelin on phosphocreatine recovery in obese subjects with reduced GH.
The study found that when obese people with low growth hormone got more IGF-I, their muscles recovered energy faster after exercise — but it didn’t test if they got stronger or used more energy upfront, so it supports the idea that IGF-I helps mitochondria recover, not muscles get stronger.