The 24-hour molecular landscape after exercise in humans reveals MYC is sufficient for muscle growth.

A detailed understanding of molecular responses to a hypertrophic stimulus in skeletal muscle leads to therapeutic advances aimed at promoting muscle mass. To decode the molecular factors regulating skeletal muscle mass, we utilized a 24-h time course of human muscle biopsies after a bout of resistance exercise. Our findings indicate: (1) the DNA methylome response at 30 min corresponds to upregulated genes at 3 h, (2) a burst of translation- and transcription-initiation factor-coding transcripts occurs between 3 and 8 h, (3) changes to global protein-coding gene expression peaks at 8 h, (4) ribosome-related genes dominate the mRNA landscape between 8 and 24 h, (5) methylation-regulated MYC is a highly influential transcription factor throughout recovery.

Methylome-proteome integration after late-life voluntary exercise training reveals regulation and target information for improved skeletal muscle health.

Exercise is a potent stimulus for combatting skeletal muscle ageing. To study the effects of exercise on muscle in a preclinical setting, we developed a combined endurance-resistance training stimulus for mice called progressive weighted wheel running (PoWeR). PoWeR improves molecular, biochemical, cellular and functional characteristics of skeletal muscle and promotes aspects of partial epigenetic reprogramming when performed late in life (22-24 months of age).

Fast and slow myofiber nuclei, satellite cells, and size distribution with lifelong endurance exercise in men and women.

We previously observed lifelong endurance exercise (LLE) influenced quadriceps whole-muscle and myofiber size in a fiber-type and sex-specific manner. The current follow-up exploratory investigation examined myofiber size regulators and myofiber size distribution in vastus lateralis biopsies from these same LLE men (n = 21, 74 ± 1 years) and women (n = 7, 72 ± 2 years) as well as old, healthy nonexercisers (OH; men: n = 10, 75 ± 1 years; women: n = 10, 75 ± 1 years) and young exercisers (YE; men: n = 10, 25 ± 1 years; women: n = 10, 25 ± 1 years). LLE exercised ~5 days/week, ~7 h/week for the previous 52 ± 1 years.

Exercise microdosing for skeletal muscle health applications to spaceflight.

Findings from a recent 70-day bedrest investigation suggested intermittent exercise testing in the control group may have served as a partial countermeasure for skeletal muscle size, function, and fiber-type shifts. The purpose of the current study was to investigate the metabolic and skeletal muscle molecular responses to the testing protocols. Eight males (29 ± 2 yr) completed muscle power (6 × 4 s; peak muscle power: 1,369 ± 86 W) and V̇o (13 ± 1 min; 3.

Integrated single-cell multiome analysis reveals muscle fiber-type gene regulatory circuitry modulated by endurance exercise.

Endurance exercise is an important health modifier. We studied cell-type specific adaptations of human skeletal muscle to acute endurance exercise using single-nucleus (sn) multiome sequencing in human vastus lateralis samples collected before and 3.5 hours after 40 min exercise at 70% VOmax in four subjects, as well as in matched time of day samples from two supine resting circadian controls.

Multitissue responses to exercise: a MoTrPAC feasibility study.

We assessed the feasibility of the Molecular Transducers of Physical Activity Consortium (MoTrPAC) human adult clinical exercise protocols, while also documenting select cardiovascular, metabolic, and molecular responses to these protocols. After phenotyping and familiarization sessions, 20 subjects (25 ± 2 yr, 12 M, 8 W) completed an endurance exercise bout ( = 8, 40 min cycling at 70% V̇o), a resistance exercise bout ( = 6, ∼45 min, 3 sets of ∼10 repetition maximum, 8 exercises), or a resting control period ( = 6, 40 min rest). Blood samples were taken before, during, and after (10 min, 2 h, and 3.

Human adipose and skeletal muscle tissue DNA, RNA, and protein content.

The purpose of this project was to provide a profile of DNA, RNA, and protein content in adipose tissue, which is relatively understudied in humans, to gain more insight into the amount of tissue that may be required for various analyses. Skeletal muscle tissue was also investigated to provide a direct comparison into potential differences between these two highly metabolically active tissues. Basal adipose and skeletal muscle tissue samples were obtained from 10 (7 M, 3 W) recreationally active participants [25 ± 1 yr; 84 ± 3 kg, maximal oxygen consumption (V̇o): 3.

Single muscle fibre contractile characteristics with lifelong endurance exercise.

Key Points: A hallmark trait of ageing skeletal muscle health is a reduction in size and function, which is most pronounced in the fast muscle fibres. We studied older men (74 ± 4 years) with a history of lifelong (>50 years) endurance exercise to examine potential benefits for slow and fast muscle fibre size and contractile function. Lifelong endurance exercisers had slow muscle fibres that were larger, stronger, faster and more powerful than young exercisers (25 ± 1 years) and age-matched non-exercisers (75 ± 2 years).

Influence of low-dose aspirin, resistance exercise, and sex on human skeletal muscle PGE /COX pathway activity.

Prostaglandin (PG) E  has been linked to increased inflammation and attenuated resistance exercise adaptations in skeletal muscle. Nonaspirin cyclooxygenase (COX) inhibitors have been shown to reduce these effects. This study examined the effect of low-dose aspirin on skeletal muscle COX production of PGE at rest and following resistance exercise.

Skeletal muscle size, function, and adiposity with lifelong aerobic exercise.

We examined the influence of lifelong aerobic exercise on skeletal muscle size, function, and adiposity. Young exercisers [YE; = 20, 10 women (W), 25 ± 1 yr], lifelong exercisers (LLE; = 28, 7 W, 74 ± 2 yr), and old healthy nonexercisers (OH; = 20, 10 W, 75 ± 1 yr) were studied. On average, LLE exercised 5 days/wk for 7 h/wk over the past 52 ± 1 yr.