Journal News

The molecular biology behind exercise

Meric Ozturk
Oct. 1, 2024

Lifting and lowering weight — these two actions affect muscle structure differently. During a bicep curl, lifting a weight shortens the muscle and lowering lengthens it. We call these activities concentric and eccentric exercises, respectively. Studying these exercises is crucial in sports medicine because they affect strength, bulk and rehabilitation outcomes differently.

Understanding the biology behind muscle movement also helps to optimize exercise protocols, and a recent study by Jiawei Du and a team at the Beijing Sport University in China, published in the journal Molecular & Cellular Proteomics, seeks to do that.

Muscles are made of long thin individual fibers such as those seen running diagonally across the top right of the image. The lower left shows muscle fibers stretching toward the viewer.

“This study aimed to explore the molecular mechanisms underlying muscle adaptation to eccentric and concentric exercises by using advanced proteomic techniques,” Du said. “This aligns with our broader goal of optimizing training regimens for athletes and individuals undergoing rehabilitation.”

Cells must adapt to changing energy requirements and changing muscle shapes that result from exercise. This adaptation process requires some regulations at the genetic level. Thus, examining these changes helps us to understand what happens in the cells during exercise. With advances in next-generation sequencing technology and other proteomic techniques, researchers can analyze the global genome or proteome profiles and compare them before and after exercise.

In the MCP study, two groups of men did either concentric or eccentric resistance training for four weeks. Muscle biopsies taken before and after training were analyzed to identify and quantify proteins. The scientists investigated 3,172 proteins in total, and they found that expression changed in 122 proteins during eccentric exercise and in 101 proteins during concentric exercise.

“Use of comprehensive proteomic analysis has provided detailed insights into the molecular adaptations in muscle tissue during training,” Du said. “For instance, proteins related to oxidative phosphorylation were inhibited in eccentric but activated in concentric training, indicating different metabolic adaptations. This distinction provides new insights into how specific training types can be tailored for desired outcomes in muscle performance and recovery.”

Oxidative phosphorylation is a metabolic process that uses oxygen to generate high-energy molecules in the form of adenosine triphosphate, or ATP. Before this work, other scientists had reported that strength training increases oxidative phosphorylation in mitochondria, the organelles that power cells. However, no researchers had yet determined how specific types of training can change expression of proteins related to oxidative phosphorylation.

Twenty young men participated in this study. Considering physiological, especially hormonal differences between males and females, the findings could differ with women.

“For example,” Du said, “estrogen has a protective effect on muscle, potentially leading to less muscle fiber damage and different protein expression patterns in response to the same training protocols.”

The findings have broad implications for sports science, particularly in the design of training and rehabilitation programs. The group plans to extend exercise duration in future trials to observe long-term adaptations. Also, they think that observing a more diverse participant pool, including women, older adults and athletes from various sports, would help generalize the findings and further detail the molecular mechanisms across different populations.

Enjoy reading ASBMB Today?

Become a member to receive the print edition four times a year and the digital edition monthly.

Learn more
Meric Ozturk

Meric Ozturk is a Ph.D. student in biochemistry at Iowa State University and an ASBMB Today volunteer contributor.

Get the latest from ASBMB Today

Enter your email address, and we’ll send you a weekly email with recent articles, interviews and more.

Latest in Science

Science highlights or most popular articles

What’s in a diagnosis?
Essay

What’s in a diagnosis?

Sept. 4, 2025

When Jessica Foglio’s son Ben was first diagnosed with cerebral palsy, the label didn’t feel right. Whole exome sequencing revealed a rare disorder called Salla disease. Now Jessica is building community and driving research for answers.

Peer through a window to the future of science
Annual Meeting

Peer through a window to the future of science

Sept. 3, 2025

Aaron Hoskins of the University of Wisconsin–Madison and Sandra Gabelli of Merck, co-chairs of the 2026 ASBMB annual meeting, to be held March 7–10, explain how this gathering will inspire new ideas and drive progress in molecular life sciences.

Glow-based assay sheds light on disease-causing mutations
Journal News

Glow-based assay sheds light on disease-causing mutations

Sept. 2, 2025

University of Michigan researchers create a way to screen protein structure changes caused by mutations that may lead to new rare disease therapeutics.

How signals shape DNA via gene regulation
Journal News

How signals shape DNA via gene regulation

Aug. 19, 2025

A new chromatin isolation technique reveals how signaling pathways reshape DNA-bound proteins, offering insight into potential targets for precision therapies. Read more about this recent MCP paper.

A game changer in cancer kinase target profiling
Journal News

A game changer in cancer kinase target profiling

Aug. 19, 2025

A new phosphonate-tagging method improves kinase inhibitor profiling, revealing off-target effects and paving the way for safer, more precise cancer therapies tailored to individual patients. Read more about this recent MCP paper.

How scientists identified a new neuromuscular disease
Feature

How scientists identified a new neuromuscular disease

Aug. 14, 2025

NIH researchers discover Morimoto–Ryu–Malicdan syndrome, after finding shared symptoms and RFC4 gene variants in nine patients, offering hope for faster diagnosis and future treatments.