Research

Hormonal

Simultaneous strength and endurance training (concurrent training) results in compromised adaptations compared to single-mode training due to conflicting molecular signaling pathways (Akt-mTOR vs. AMPK-PGC-1).

If your primary goal is to maximize both strength and endurance simultaneously, be aware that you will likely achieve less in both areas than if you focused on one at a time. To mitigate this 'interference effect,' separate your strength and endurance sessions by at least 6-8 hours, or prioritize one modality in a given training block while maintaining the other at a low volume.

GoodSupportsHIGH confidence
Simultaneously training for both strength and endurance results in a compromised adaptation, compared with training for either exercise mode alone. This has been variously described as the concurrent training effect or the interference effect.
John A. Hawley · Applied Physiology Nutrition and Metabolism · 2009

Why this rating

Based on a review of multiple human and animal studies showing consistent molecular conflicts.

Source

Molecular responses to strength and endurance training: Are they incompatible?This paper article is one of a selection of papers published in this Special Issue, entitled 14th International Biochemistry of Exercise Conference – Muscles as Molecular and Metabolic Machines, and has undergone the Journal’s usual peer review process.

John A. Hawley · Applied Physiology Nutrition and Metabolism · 2009

DOI 10.1139/h09-023

narrative_reviewCited 195×
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DOI resolved against Crossref · corpus check 2026-06-10

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