The age-related decline in skeletal muscle mass and strength, termed sarcopenia, results in impairments in functional capacity ( Baumgartner et al., 1998 ; Mitchell et al., 2012 ). Aging is associated with the maladaptation of muscle collagenous tissue (i.e., connective tissue), which transfers
Andrew M. Holwerda, Jorn Trommelen, Imre W.K. Kouw, Joan M. Senden, Joy P.B. Goessens, Janneau van Kranenburg, Annemie P. Gijsen, Lex B. Verdijk, and Luc J.C. van Loon
Rebekah D. Alcock, Gregory C. Shaw, Nicolin Tee, Marijke Welvaert, and Louise M. Burke
collagen synthesis, potentially enhancing the growth and/or repair of connective tissues ( Curtis, 2016 ). Among the nutrients known to be involved in collagen synthesis, there is emerging evidence regarding the key roles played by the amino acids abundantly present in collagen protein (such as proline and
Isabel Mayer, Matthias W. Hoppe, Jürgen Freiwald, Rafael Heiss, Martin Engelhardt, Casper Grim, Christoph Lutter, Moritz Huettel, Raimund Forst, and Thilo Hotfiel
, several studies revealed a significant short-term increase of ROM for the hip, 11 , 18 knee, 3 , 19 and ankle 11 , 20 joint. However, to date, the physiological mechanisms and underlying changes of connective tissue, particularly those of the fascial connective tissue, are not completely understood. 21
Joel L. Prowting, Debra Bemben, Christopher D. Black, Eric A. Day, and Jason A. Campbell
degree of muscle tissue damage that transiently results in reduced force production and increased muscle soreness ( Peake et al., 2016 ). In addition, there is evidence that eccentric exercise damages connective tissues ( Brown et al., 1997 ), including the extracellular matrix (ECM) that supports and
Dana M. Lis and Keith Baar
these tissues may have an effect on performance. Dietary supplementation with gelatin or hydrolyzed collagen (HC) products has become popular among athletes aiming to improve connective tissue function and prevent or treat injury. However, the scientific validity of these nutritional interventions lags
Eric S. Rawson, Mary P. Miles, and D. Enette Larson-Meyer
the adaptive response to exercise focuses on dietary supplements that affect skeletal muscle tissue, MPS, and MPB. However, nutritional interventions that could benefit connective tissue proteins would valuable as well (reviewed in Baar, 2017 ). Shaw et al. ( 2017 ) showed the combination of exercise
Gil Rodas, Lourdes Osaba, David Arteta, Ricard Pruna, Dolors Fernández, and Alejandro Lucia
abbreviations. One of the most robust SNPs we identified was the rs10477683 variant located in the fibrillin 2 gene, characterized by nonzero coefficients in 4 training sets. The protein encoded by this gene is a component of connective tissue microfibrils and might be involved in elastic fiber assembly. Among
George J. Holland, Kiyoji Tanaka, Ryosuke Shigematsu, and Masaki Nakagaichi
This review examines the influences of physiological aging processes on connective tissue, joint integrity, flexibility (range of motion [ROM]), and physical functions of older adults. Studies that attempted to improve older adults' ROM are also critiqued. Multiple mechanisms of musculoskeletal and soft-tissue degeneration, as well as disease processes (osteoporosis, arthritis, atherosclerosis), contribute to significant decreases in neuromuscular function and ROM in older adults, all of which can be exacerbated by disuse influences. No delineation of disuse effects on the rate of aging-related decrements in ROM can be provided, however, because long-term investigations (with physical activity controls) have not been conducted. Research efforts have documented both upper and lower extremity decrements in ROM with development of physical impairments, reductions in basic and instrumental activities of daily living, and progression of disability. There is limited research evidence that either specialized stretch-training or general-exercise intervention protocols moderately improve ROM in older adults and the frail elderly.
Dawn T. Gulick and Iris F. Kimura
Muscle soreness, a familiar phenomenon to most athletes, has been differentiated into “acute” and “delayed onset.” The etiology of acute muscle soreness has been attributed to ischemia and the accumulation of metabolic by-products. However, the etiology of delayed onset muscle soreness (DOMS) is not so clear. Six theories have been proposed: lactic acid, muscle spasm, torn tissue, connective tissue, enzyme efflux, and tissue fluid theories. The treatment of DOMS has also been investigated. Studies in which anti-inflammatory medications have been administered have yielded varying results based on the dosage and the time of administration. Submaximal concentric exercise may alleviate soreness but does not restore muscle function. Neither cryotherapy nor stretching abates the symptoms of DOMS. Transcutaneous electrical stimulation has been shown to decrease soreness and increase range of motion, but the effect on the recovery of muscle function is unknown. Therefore, the treatment of DOMS remains an enigma.
Shameemah Abrahams, Michael Posthumus, and Malcolm Collins
Endurance-running performance and joint range of motion (ROM) are both multifactorial phenotypes. A single-nucleotide polymorphism, rs172722 (C/T), in the COL5A1 3′-untranslated region (UTR) was shown to independently associate with both phenotypes. Two major functional forms of the COL5A1 3′-UTR have been identified and differ by 7 tightly linked polymorphisms that include rs12722 and a short tandem-repeat polymorphism (STRP rs71746744, –/AGGG). It has been proposed that STRP rs71746744 plays a role in the predicted secondary structures and mRNA stability of the 2 major forms of the COL5A1 3′-UTR, therefore implying a regulatory role. The aim of this study was to determine whether STRP rs71746744 is independently associated with running performance and prerace sit-and-reach range of motion (SR ROM) in a cohort of ultramarathon road runners.
One hundred six (74 men and 32 women, age 22–67 y) white runners who participated in either the 2009 or 2011 Two Oceans 56-km ultramarathon were included in this cross-sectional study. Their SR ROM measurements, COL5A1 rs71746744 genotype, and overall race times were determined.
COL5A1 rs71746744 was independently associated with running performance (P = .024) and prerace sr rom (P = .020). Moreover, the AGGG/AGGG genotype was significantly overrepresented in the fastest and inflexible athletes compared with those with either the –/AGGG or –/– genotype.
These findings provide further evidence for a relationship between COL5A1, running performance, and SR ROM. Further studies are needed to investigate the effect of this variant on the mechanical properties of connective tissue.