Telomeres act as a mitotic clock and telomere-related senescence has been linked to age-related physiological decline. There is increasing evidence lifestyle factors can influence telomere length (TL). The purpose of this study was to determine the effect of competitive triathlon training on TL. Seven competitive male triathletes and seven recreationally active males participated in the study. Relative TL was measured using quantitative polymerase chain reaction. Physiological parameters key to athletic performance such as maximal oxygen intake, lactate threshold, and running economy were also measured. Triathletes had longer telomeres than the recreationally active (1.257 ± 0.028 vs. 1.002 ± 0.014; p < .0001). Positive association was found between TL and maximal oxygen intake, lactate threshold, and running economy (R 2 = .677, .683, and .696, respectively). This study indicates that competitive triathlon training buffers against age-related telomere shortening, and there is a correlation between exercise behaviors, higher maximal oxygen intake, and TL.
Marcus Colon, Andrew Hodgson, Eimear Donlon and James E.J. Murphy
Dimitrios-Sokratis Komaris, Cheral Govind, Andrew Murphy, Alistair Ewen and Philip Riches
Patients with osteoarthritis of the knee commonly alter their movement to compensate for lower limb weakness and alleviate joint pain. Movement alterations may lead to weight-bearing asymmetries, and potentially to the progression of the disease. This study presents a novel numerical procedure for the identification of sit-to-walk strategies and differences in movement habits between control adults and persons with knee osteoarthritis. Ten control and 12 participants with osteoarthritis performed the sit-to-walk task in a motion capture laboratory. Participants sat on a stool with the height adjusted to 100% of their knee height, then stood and walked to pick up an object from a table in front of them. Different movement strategies were identified by means of hierarchical clustering. Trials were also classified as to whether the left and right extremities used a bilateral or an asymmetrical strategy. Participants with osteoarthritis used significantly more asymmetrical arm strategies (P = .03) while adopting the pushing through the chair strategy more often than the control subjects (P = .02). The results demonstrated that the 2 groups favor different sit-to-walk strategies. Asymmetrical arm behavior possibly indicates a compensation for the weakness of the affected leg. The proposed procedure may be useful to rapidly assess postoperative outcomes and developing rehabilitation strategies.
Mohanraj Krishnan, Andrew N. Shelling, Clare R. Wall, Edwin A. Mitchell, Rinki Murphy, Lesley M.E. McCowan and John M.D. Thompson
Purpose: The decline of physical activity in children is considered an important determinant to explain the rising rates of obesity. However, this risk may be augmented in children who are genetically susceptible to increased weight gain. We hypothesized that a sedentary lifestyle and moderate activity will interact with genetic loci, resulting in differential effects in relation to obesity risk. Methods: We recruited 643 European children born to participants in the New Zealand-based Screening for Pregnancy Endpoints (SCOPE) study. Seventy gene variants were evaluated by the Sequenom assay. Interaction analyses were performed between the genetic variants and the activity type derived from actigraphy, in relation to percentage body fat. Results: We found a statistically significant association between increased proportions of sedentary activity with increased percentage body fat scores (P = .012). The OLFM4-9568856 (P = .01) and GNPDA2-rs10938397 (P = .044) gene variants showed genotype differences with proportions of sedentary activity. Similarly, the OLFM4-9568856 (P = .021), CLOCK-rs4864548 (P = .029), and LEPR-1045895 (P = .047) showed genotype differences with proportions of moderate activity. We found evidence for unadjusted gene-by-activity interactions of SPACA3/SPRASA-rs16967845, PFKP-rs6602024, and SH2B1-rs7498665 on percentage body fat scores. Conclusions: These findings indicate a differential effect of physical activity in relation to obesity risk, suggesting that children genetically predisposed to increased weight gain may benefit from higher levels of moderate activity.