'Take a Mental Break!' study: Role of mental aspects in running-related injuries using a randomised controlled trial

Background

Running-related injuries (RRIs) can be considered the primary enemy of runners. Most literature on injury prediction and prevention overlooks the mental aspects of overtraining and under-recovery, despite their potential role in injury prediction and prevention. Consequently, knowledge on the role of mental aspects in RRIs is lacking.

Objective

To investigate mental aspects of overtraining and under-recovery by means of an online injury prevention programme.

Methods and analysis

The ‘Take a Mental Break!’ study is a randomised controlled trial with a 12 month follow-up. After completing a web-based baseline survey, half and full marathon runners were randomly assigned to the intervention group or the control group. Participants of the intervention group obtained access to an online injury prevention programme, consisting of a running-related smartphone application. This app provided the participants of the intervention group with information on how to prevent overtraining and RRIs with special attention to mental aspects. The primary outcome measure is any self-reported RRI over the past 12 months. Secondary outcome measures include vigour, fatigue, sleep and perceived running performance. Regression analysis will be conducted to investigate whether the injury prevention programme has led to a lower prevalence of RRIs, better health and improved perceived running performance.

Ethics and dissemination

The Medical Ethics Committee of the University Medical Center Utrecht, the Netherlands, has exempted the current study from ethical approval (reference number: NL64342.041.17). Results of the study will be communicated through scientific articles in peer-reviewed journals, scientific reports and presentations on scientific conferences.

Modified indirect immunodetection allows study of murine tissue with mouse monoclonal antibodies

The indirect immunodetection method is powerful in detecting antigens in situ, but to date mouse monoclonal antibodies (MAbs) could not be used in immunohistochemical studies of murine tissues without severe background staining. We report here a modification of this method in which mouse MAbs are used to detect murine antigens in cryosections. Before application to the section, mouse MAbs and conjugated anti-mouse antiserum were allowed to complex in vitro. After blocking of the unbound secondary antiserum with normal mouse serum, standard immunohistochemistry was performed. Fifty percent of a randomly chosen panel of over 40 mouse MAbs recognized their antigens in our model system. Adaptation of, for example, the fixation protocol can probably even increase this number. An MAb to the intermediate filament protein desmin, staining both smooth and striated muscle, was used to demonstrate this technique in cryosections of 15-day-old mouse embryos. In contrast to standard immunohistochemistry with the same antibodies under the same conditions, background staining was completely absent with this technique. With this modification to the well-established indirect detection method, the usefulness of mouse MAbs is significantly increased.

Variants of the alpha 6 beta 1 laminin receptor in early murine development: distribution, molecular cloning and chromosomal localization of the mouse integrin alpha 6 subunit

Laminin (A:B1:B2) is a major component of the first basement membrane to appear in the developing mouse embryo. Its effects on morphogenesis and differentiation are mediated by interaction with cell surface receptors that are members of the integrin family. We have studied the expression of the alpha 6 subunit of murine alpha 6 beta 1 and its ligand, laminin, in preimplantation mouse embryos, embryo outgrowths and in embryonic stem (ES) cells and embryonal carcinoma (EC) cells. The alpha 6 subunit is present in the oocyte and throughout preimplantation development. Laminin A chain appears later than alpha 6 and has a more restricted distribution until the late blastocyst stage. alpha 6 beta 1 is strongly expressed in ES and EC cells; the levels of mRNA expression are not altered by differentiation. Molecular cloning of cDNA for the murine integrin alpha 6 subunit from a mammary gland lambda gt11 library showed, as in man, an open reading frame encoding two variants of alpha 6, alpha 6A and alpha 6B. The identity of the alpha 6 amino acid sequence to that in man and chicken is 93% and 73%, respectively. The gene for murine alpha 6 was mapped to chromosome 2. While undifferentiated ES and EC cells express only alpha 6B, alpha 6A is co-expressed in ES cells after differentiation is induced by retinoic acid. alpha 6B is also the only variant expressed in blastocyst stage embryos, but when blastocysts have grown out in culture both alpha 6A and alpha 6B are expressed reflecting the results in the cell lines. We suggest that the deposition of laminin in the embryo is a receptor-mediated process and that the shift in the expression of the variants, as the inner cell mass forms its first differentiated progeny, reflects a change in functional properties.