Research
Hormonal
Resistance exercise stimulates muscle hypertrophy primarily through the activation of the mTOR pathway via PKB, while endurance exercise stimulates mitochondrial biogenesis primarily through AMPK activation of PGC-1alpha.
Understanding that strength and endurance use different molecular switches helps explain why you cannot maximize both simultaneously. To build muscle, focus on high-intensity resistance to activate PKB/mTOR. To improve endurance, focus on duration to activate AMPK/PGC-1alpha.
StrongSupportsVERY_HIGH confidence
Protein kinase B/Akt can both activate protein synthesis and decrease protein breakdown, thus leading to hypertrophy, and AMP-activated protein kinase can increase mitochondrial protein, glucose transport, and a number of other factors that result in an endurance phenotype.
Why this rating
The paper cites multiple studies confirming these pathways in various models (chickens, rabbits, rats, humans).
Source
Training for Endurance and Strength
Keith Baar · Medicine & Science in Sports & Exercise · 2006
DOI 10.1249/01.mss.0000233799.62153.19
narrative_reviewCited 179×
Read the paper DOI resolved against Crossref · corpus check 2026-06-10
Related findings · Hormonal
- Initial treatment for type 2 diabetes should be a combination of metformin and either an SGLT-2 inhibitor or a GLP-1 receptor agonist to achieve cardiorenal protection, rather than monotherapy or older agents like sulfonylureas.Strong
- For patients with specific monogenic obesity syndromes (leptin deficiency, POMC/PCSK1/LEPR mutations), targeted pharmacotherapy (recombinant leptin or setmelanotide) is highly effective and should be prioritized, unlike in polygenic obesity.Strong
- Continued weekly administration of 2.4 mg subcutaneous semaglutide prevents weight regain and promotes further weight loss in adults with overweight or obesity, whereas switching to placebo results in significant weight regain.Strong
This is one finding among thousands. Every one is graded and traced to its source, so you can see what the evidence actually supports. Browse the research →