Research hotspots and trends of exercise for sarcopenia: A bibliometric analysis

“

TL;DR

This bibliometric analysis of 5,507 publications from 2003 to 2022 maps the research landscape of exercise interventions for sarcopenia using CiteSpace visualization software. The United States leads in publication volume, while resistance exercise remains the most studied intervention, with emerging interest in high-intensity interval training, insulin resistance, and heart failure-related sarcopenia. The findings highlight that exercise, particularly resistance training, is the cornerstone of sarcopenia rehabilitation, and future research should focus on optimizing exercise prescriptions and understanding underlying mechanisms.

Full summary

4,835 CHARS

**Background:** Sarcopenia is an age-related condition characterized by loss of muscle mass, strength, and physical performance, increasing risks of falls, disability, cardiovascular disease, and mortality. With no effective pharmacological treatments available, exercise is a key recommended intervention. This study aimed to comprehensively summarize research on exercise interventions for sarcopenia using bibliometric analysis to identify hotspots, trends, and knowledge structures over the past two decades.

**Methods:** The Web of Science Core Collection was searched on July 24, 2022, using the query: Topic = (sarcopenia) AND Topic = ("exercise" OR "training" OR "sport" OR "movement" OR "motion"). Inclusion criteria were articles and reviews published in English with no date restriction. A total of 5,507 records were retrieved. Data were standardized and analyzed using Microsoft Excel 2021 and CiteSpace 6.1.R2. Descriptive analyses included annual publication counts, journals, countries, institutions, authors, keywords, and citation patterns. Co-occurrence networks, cluster analyses, and burst detection were performed to identify research hotspots and frontiers.

**Key Results:** The first publication appeared in 2003, and annual output grew slowly until 2013, after which it increased rapidly. The top five most productive journals were Experimental Gerontology (225 articles), Nutrients (191), Journal of Cachexia Sarcopenia and Muscle (121), PLoS ONE (115), and Journals of Gerontology Series A-Biological Sciences and Medical Sciences (85). The most cited journal was J Gerontol A-Biol (3,433 citations). Publications originated from 84 countries; the USA led with 1,619 publications, followed by Japan (612), England (501), China (489), and Italy (465). Australia had the highest centrality (0.27), indicating influential collaborative importance. The top five institutions were Maastricht University, University of Florida, University of Melbourne, Tufts University, and McMaster University. Tufts University (centrality 0.12) and University of Florida (centrality 0.1) were identified as core institutions. Among 1,019 authors, VAN LOON LJC was the most productive (53 publications), while CRUZ-JENTOFT A was the most cited author (1,878 citations). The most cited references were the EWGSOP consensus definitions for sarcopenia (Cruz-Jentoft et al., 2010 and 2019) and AWGS consensus (Chen et al., 2014 and 2020). The reference with highest centrality (0.17) was Koopman R (2009) on aging, exercise, and muscle protein metabolism. Cluster analysis of cited references (Q=0.6939, S=0.8654) identified topics including resistance training, apoptosis/mitochondria, skeletal muscle, protein, amino acid, heart failure, cirrhosis, proteomics, monoclonal antibody, and machine learning. Keyword analysis (768 nodes, 9,176 links) revealed top high-frequency keywords: sarcopenia (1,692), skeletal muscle (1,544), exercise (1,020), body composition (898), strength (719), older adult (685), physical activity (627), mass (485), resistance exercise (474), and muscle strength (433). The keyword with strongest burst was "elderly men" (strength 27.33), followed by "growth factor" (21.68). Recent burst keywords included "Asian working group" and "consensus." Keyword clustering (Q=0.3397, S=0.669) generated six clusters: skeletal muscle, muscle strength, heart failure, muscle protein synthesis, insulin resistance, and high-intensity interval training. The timeline view showed "insulin resistance" and "high-intensity interval training" as the most recent research frontiers.

**Clinical Implications:** This analysis confirms that exercise, particularly resistance training, is the most significant and widely studied intervention for sarcopenia rehabilitation. Resistance exercise effectively enhances muscle protein synthesis, hypertrophy, and strength, with recommended programs of at least 8 weeks, 3–4 times per week at 40–60% of 1-repetition maximum. Aerobic exercise improves cardiorespiratory endurance and mitochondrial function but does not stimulate hypertrophy. Multi-component exercise combining resistance, aerobic, balance, and flexibility training is clinically preferred for its superior effectiveness and adherence. High-intensity interval training is an emerging modality but requires careful safety assessment before application in sarcopenic populations. Exercise combined with nutritional supplementation (protein, amino acids, vitamin D) is identified as the optimal rehabilitation strategy. The study highlights that sarcopenia in heart failure, insulin resistance, and muscle protein synthesis pathways are key areas for future mechanistic research. Limitations include exclusive use of the Web of Science database, English-language restriction, and time-dependent citation variability.