{"doi":"10.3390/nu14030454","title":"Short-Term Adaptations in Skeletal Muscle Mitochondrial Oxidative Capacity and Metabolic Pathways to Breaking up Sedentary Behaviors in Overweight or Obese Adults","abstract":"Breaking up sedentary behavior with short-frequent bouts of physical activity (PA) differentially influences metabolic health compared with the performance of a single-continuous bout of PA matched for total active time. However, the underlying mechanisms are unknown. We compared skeletal muscle mitochondrial respiration (high-resolution respirometry) and molecular adaptations (RNA sequencing) following 4-day exposure to breaks vs. energy-matched single-continuous PA bout in inactive adults with overweight/obesity. Participants (9M/10F, 32.2 ± 6.4 years, 30.3 ± 3.0 kg/m2) completed three 4-day interventions of a randomized cross-over study: SED, sedentary control; MICRO, 5 min brisk walking each hour for 9 h; ONE: 45 min/d continuous brisk walking bout. Fasted muscle biopsies were collected on day 5. Mitochondrial coupling in the presence of lipid-associated substrates was higher after ONE (4.8 ± 2.5) compared to MICRO (3.1 ± 1.1, p = 0.02) and SED (2.3 ± 1.0, p = 0.001). Respiratory rates did not differ across groups with carbohydrate-associated substrates. In pathways associated with muscle contraction transcription signaling, ONE and MICRO similarly enhanced Oxidative Phosphorylation and Sirtuin Signaling expression (p < 0.0001, for both). However, ONE (p < 0.001, for all), but not MICRO, had greater pathway enrichment, including Ca++, mTOR, AMPK, and HIF1α signaling, than SED. Although breaking up sedentary behavior triggered skeletal muscle molecular adaptations favoring oxidative capacity, it did not improve mitochondrial function over the short term.","journal":"Nutrients","year":2022,"id":281920,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":7,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.948,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2022-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":323527,"name":"Michael C. Rudolph","orcid":"0000-0002-6147-212X","position":1,"is_corresponding":false},{"id":395395,"name":"Matthew R. Jackman","orcid":"0000-0002-1639-3879","position":2,"is_corresponding":false},{"id":681841,"name":"Rachel R. Sharp","orcid":"0000-0002-3070-9200","position":3,"is_corresponding":false},{"id":833929,"name":"Ken Jones","orcid":null,"position":4,"is_corresponding":false},{"id":488683,"name":"Julie A. Houck","orcid":"0000-0002-5906-1022","position":5,"is_corresponding":false},{"id":414366,"name":"Zhaoxing Pan","orcid":"0000-0002-9319-2501","position":6,"is_corresponding":false},{"id":276837,"name":"Jane E.B. Reusch","orcid":"0000-0001-8620-1003","position":7,"is_corresponding":false},{"id":348565,"name":"Paul S. MacLean","orcid":"0000-0002-1123-6612","position":8,"is_corresponding":false},{"id":263221,"name":"Daniel H. Bessesen","orcid":"0000-0002-8242-9198","position":9,"is_corresponding":false},{"id":230026,"name":"Audrey Bergouignan","orcid":"0000-0002-1266-5144","position":10,"is_corresponding":false},{"id":645072,"name":"Nathan P. De Jong","orcid":"0000-0003-0298-6777","position":0,"is_corresponding":true}],"reference_count":37,"raw_metadata":null,"created_at":"2026-07-19T00:29:15.734856Z","pmid":"35276813","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}