Date of Award


Document Type

Doctoral Thesis

Degree Name

Doctor of Philosophy


Biological Sciences

First Advisor

Dr. Jim O'Mahony


Whilst all military cohorts have been seen to experience both physiological and psychological stressors during occupational duties, the naval service experience different stressors due the prolonged periods of time spent at sea. Research has analysed some of these stressors however many them have focused on how individuals are affected because of time spent in combat zones. The Irish Naval Service (INS) is an organisation under the Irish Defence Forces organisation and as such many of its physiological and psychological assessment procedures have come from the Defenee Forces. Very limited researeh has been carried out in relation to the INS as a separate entity. As a result, the aims of this research were to:

• Create a physiological scoring system specifically for the INS

• Evaluate the baseline physiological levels of personnel within the INS and the impact certain variables have on physiological wellbeing

• Evaluate the psychological baseline levels of personnel within the INS and assess the impact certain variables are having on psychological wellbeing

In order to achieve these aims, personnel were assessed under three different headings: physical fitness, body composition and psychological.

To assess physical fitness levels each participant completed physical fitness tests that assessed various components of physical fitness. These included: flexibility (sit and reach test), power (vertical jump test, standing long jump test), agility (pro agility test), strength (hand grip strength, chin up test, push up test, sit up test), speed (over 5-metres, over 10-metres), anaerobic conditioning (5-metre multiple shuttle run test), aerobic conditioning (multi-stage fitness test). From the data produced because of these tests, a quantitative scoring system was created that allows a comprehensive analysis of physical fitness to be conducted. The scoring system enabled each participant to be scored out of a possible 30 points for each of the twelve tests completed. If all twelve tests are used then the maximum overall that could be obtain by any individual is 360 points. The flexible nature of the scoring system allows for tests to be included or excluded to suit the needs of the individual or the organisation. However, until research has been condueted to assess whieh components of physieal fitness are essential to occupational performance, it is recommended that all components remain in the testing process.

When the physical fitness data was compared to that of other military cohorts, personnel within this study were seen to perform similarly or better, apart from the scores for the hand grip test and the multi-stage fitness test. Vertical power (r=-0.525, p

As already mentioned personnel within the INS spend prolonged periods of time at sea. As a result, the environment on-board naval vessels can have an impact on physical fitness. Of the four classes of vessels (coastal patrol vessel, helicopter patrol vessel, large patrol vessel and off shore patrol vessel), the coastal patrol vessels were found to have the poorest fitness facilities and individuals on-board these vessels exercised significantly less whilst at sea when compared with shore based (p

Body composition was assessed using several methods including body mass index (BMI), skin- folds and waist to hip ratio. Body composition was found to increase as age increased and as the number of years in the service increased. Body composition was also found to be higher for smokers than non-smokers, however, this had not reached a significant level yet. The amount of time spent exercising was found to have a positive impact on body composition apart from BMI with which it had no correlation. This may indicate that BMI is not suitable for use within the INS due to the muscular body composition.

Three questionnaires were used to assess various aspects of psychological wellbeing. These were: GHQ-12 (used to assess general mental health), NEO-FFI (used to assess personality traits) and CISS (used to assess the ability to cope in stressful situations). Results showed that the longer an individual spent in the INS the more likely they were of having a common mental health disorder. Avoidance was used as the most common coping mechanism for stressful situations, however, the use of this mechanism was found to decrease with age. The highest percentage of participants scored in the ‘high’ category for extraversion and in the average category for the other four personality types (neuroticism, openness to experience, agreeableness and conscientiousness).

High scores for neuroticism were found to be linked to poor levels of general mental health and those who scored high were also found to use emotion or social diversion coping styles in stressful situations. In contrast, high levels of conscientiousness were linked to good general mental health and individuals who scored high for conscientiousness were also found to use task related coping to deal with stressful situations. These results could indicate that the NEO- FFI could be used as a recruitment or promotional tool within the INS.

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