Background: An adequate level of muscular fitness is related to occupational performance in military personnel, including pilots flying high performance aircraft. The aim of this study was to describe the baseline level and the change in muscular fitness between the first and the second years of the Air Force Academy among fighter pilot cadets. Methods: The muscular strength and endurance test results of 182 male fighter pilot cadets were analyzed during their first year in the Air Force Academy and one year after. Maximal isometric strength tests included trunk flexion, trunk extension and bilateral leg extension tests, whereas muscle endurance was measured with modified a sit-up test and seated alternative dumbbell press. Results: The maximal isometric bilateral strength of the leg extensor muscles increased from 220 ± 42 to 232 ± 42 kg. The maximal isometric trunk extension strength increased from 117 ± 21 to 120 ± 19 kg and trunk flexion from 82 ± 16 to 86 ± 17 kg. Muscle endurance increased from 68 ± 13 to 75 ± 15 repetitions/min in seated dumbbell press and from 47 ± 12 to 51 ± 13 repetitions/min in sit-up test. Conclusions: Both maximal strength and muscular endurance improved among fighter pilot cadets, which indicates that occupational performance is well maintained or improved from the perspective of physical fitness during the early phase of academy studies. Education in the Air Force Academy, including physical education, seems beneficial in improving muscular fitness among military pilots.
An adequate level of muscular fitness is related to occupational performance in military personnel, including pilots flying high performance aircraft. The aim of this study was to describe the baseline level and the change in muscular fitness between the first and the second years of the Air Force Academy among fighter pilot cadets. Methods: The muscular strength and endurance test results of 182 male fighter pilot cadets were analyzed during their first year in the Air Force Academy and one year after. Maximal isometric strength tests included trunk flexion, trunk extension and bilateral leg extension tests, whereas muscle endurance was measured with modified a sit-up test and seated alternative dumbbell press. Results: The maximal isometric bilateral strength of the leg extensor muscles increased from 220 ± 42 to 232 ± 42 kg. The maximal isometric trunk extension strength increased from 117 ± 21 to 120 ± 19 kg and trunk flexion from 82 ± 16 to 86 ± 17 kg. Muscle endurance increased from 68 ± 13 to 75 ± 15 repetitions/min in seated dumbbell press and from 47 ± 12 to 51 ± 13 repetitions/min in sit-up test. Conclusions: Both maximal strength and muscular endurance improved among fighter pilot cadets, which indicates that occupational performance is well maintained or improved from the perspective of physical fitness during the early phase of academy studies. Education in the Air Force Academy, including physical education, seems beneficial in improving muscular fitness among military pilots. ; peerReviewed
Introduction Military training loads may induce different physiological responses in garrison and field training and only a little is known about how short-time recovery, lasting a few days, affects neuromuscular fitness and hormonal profile. This study aimed to investigate the effects of garrison and field military service on neuromuscular performance and hormonal profile and to evaluate the effects of a 3-day recovery on those factors. Methods Twenty healthy male soldiers (20 ± 1 years) participated in the study, which consisted of 4 days of garrison training [days (D) 1–4] and 7 days of military field training (Days 5–12) followed by a 3-day recovery period (Day 15). Serum hormone concentrations [testosterone (TES), cortisol (COR), sex-hormone binding globulin (SHBG), free thyroxine (T4)] were assessed at D1, D5, D8–12, and D15. Handgrip strength was measured in 10 participants at D1, D5, D8, D12, and D15. Maximal isometric force, electromyography, and rate of force development (RFD) of the knee extensors and arm flexors were also measured at D5, D12, and D15. Results The maximal force of both the arm flexors and knee extensors was not affected by the garrison or field training, whereas the RFD of the knee extensors was decreased during the field training (D5: 383 ± 130 vs. D12: 321 ± 120 N/s, p < 0.05). In addition, handgrip strength was mostly no affected, although a significant difference was observed between D8 and D12 (531 ± 53 vs. 507 ± 43 N, p < 0.05) during the field training. TES decreased already during the garrison training (D1: 18.2 ± 3.9 vs. D5: 16.2 ± 4.0 nmol/L, p < 0.05) and decreased further during the field training compared to baseline (D8: 10.2 ± 3.6 - D11: 11.4 ± 5.4 nmol/L, p < 0.05) exceeding the lowest concentration in the end of the field training (D12: 7.1 ± 4.1 nmol/L, p < 0.05). Similar changes were observed in free TES (D1: 72.2 ± 31.4 vs. D12: 35.1 ± 21.5 nmol/L, p < 0.001). The TES concentration recovered back to the baseline level and free TES increased after the recovery period compared with the baseline values (D15: 19.9 ± 5.3 nmol/L, D15: 99.7 ± 41.1 nmol/L, respectively). No changes were observed in the COR or SHBG concentrations during the garrison period. COR was decreased in the end of the field training (D12: 388 ± 109 nmol/L) compared with baseline (D1: 536 ± 113 nmol/L) (p < 0.05–0.001) but recovered back to the baseline levels after the recovery period (D15: 495 ± 58 nmol/L), whereas SHBG linearly increased towards the end of the field training (p < 0.05–0.001). Conclusions The present findings demonstrate that neuromuscular performance can be relatively well maintained during short-term garrison and field training even when a clear decrease in hormonal profile is evident. In addition, hormonal responses during field training seem to be greater compared to garrison training, however, the recovery of 3-day in free-living conditions seems to be sufficient for hormonal recovery. Therefore, a short-term recovery period lasting few days after the military field training may be required to maintain operational readiness after the field training. ; peerReviewed
Abstract Objectives Worldwide decreases in physical fitness and increases in body fat among youth have set challenges for armed forces to recruit physically capable soldiers. Therefore, knowledge of optimizing physical adaptation and performance through physical training is vital. In addition, maintaining or improving physical performance among professional soldiers in various military environments is crucial for overall military readiness. The present review focuses on the effects of military training on physical performance by searching for optimal methods to do it. Design and methods Review article based on selected literature searches using the main keywords 'physical performance' and 'training' and 'military' from MEDLINE and SportDiscus® engines. Additional selected references were included that encompassed the same words but were not found in the present search. Results Military training mainly consists of prolonged physical activities and training performed at low-intensities, which may interfere with optimal muscle strength and considering development of maximal strength, power, and aerobic capacity. Combined endurance and strength training seems to be a superior training method to improve overall physical performance of soldiers. Conclusions The present study demonstrated that military training needs a greater variation in training stimulus to induce more effective training adaptations, especially, when considering the development of maximal or explosive strength and maximal aerobic capacity. Training programs should be well periodised so that total training load increases progressively but also includes sufficient recovery periods. In addition, some individualized programming is required to avoid unnecessary injuries and overloading because the differences in initial physical fitness of soldiers can be very high. ; peerReviewed
BACKGROUND: Despite numerous studies providing evidence for positive effects of physical activity and physical fitness, evidence for association between physical fitness and health-related quality of life (HRQoL) in young adults is limited. The aim of the present cross-sectional study was to investigate the association of cardiorespiratory and muscular fitness with HRQoL from the perspective of its physical and mental components among young adult Finnish males. METHODS: The sample consisted of 754 men, with the mean age of 26 years (SD 6.7 years), who participated in the military refresher training. HRQoL was measured using the Finnish RAND 36-item health survey. Cardiorespiratory fitness was determined by a bicycle ergometer test, and muscular fitness by various tests measuring maximal strength and muscular endurance. Logistic regression modelling was used to compare low, moderate and high physical and mental component of HRQoL scores to the respective levels of muscular and cardiorespiratory fitness. RESULTS: The findings of the adjusted (age, educational level, marital status, employment status, smoking, use of alcohol and BMI) analysis showed that cardiorespiratory and muscular fitness are positively associated with both physical and mental components of HRQoL. In terms of the physical component of HRQoL, even a moderate fitness level was positively associated with better HRQoL. In terms of the mental component of HRQoL, the impact was seen only in the group with the highest fitness level. CONCLUSIONS: The findings suggest a positive contribution of physical fitness to mental health and highlight the importance of both muscular and cardiorespiratory fitness in the promotion of HRQoL. Even lighter forms of physical activity that result in moderate physical fitness could contribute to the physical component of HRQoL. In terms of the mental component of HRQoL, higher levels of physical fitness may be needed to gain higher levels of HRQoL among young males.
Background Despite numerous studies providing evidence for positive effects of physical activity and physical fitness, evidence for association between physical fitness and health-related quality of life (HRQoL) in young adults is limited. The aim of the present cross-sectional study was to investigate the association of cardiorespiratory and muscular fitness with HRQoL from the perspective of its physical and mental components among young adult Finnish males. Methods The sample consisted of 754 men, with the mean age of 26 years (SD 6.7 years), who participated in the military refresher training. HRQoL was measured using the Finnish RAND 36-item health survey. Cardiorespiratory fitness was determined by a bicycle ergometer test, and muscular fitness by various tests measuring maximal strength and muscular endurance. Logistic regression modelling was used to compare low, moderate and high physical and mental component of HRQoL scores to the respective levels of muscular and cardiorespiratory fitness. Results The findings of the adjusted (age, educational level, marital status, employment status, smoking, use of alcohol and BMI) analysis showed that cardiorespiratory and muscular fitness are positively associated with both physical and mental components of HRQoL. In terms of the physical component of HRQoL, even a moderate fitness level was positively associated with better HRQoL. In terms of the mental component of HRQoL, the impact was seen only in the group with the highest fitness level. Conclusions The findings suggest a positive contribution of physical fitness to mental health and highlight the importance of both muscular and cardiorespiratory fitness in the promotion of HRQoL. Even lighter forms of physical activity that result in moderate physical fitness could contribute to the physical component of HRQoL. In terms of the mental component of HRQoL, higher levels of physical fitness may be needed to gain higher levels of HRQoL among young males. ; peerReviewed
Importance. High physical fitness is associated with a reduction in risk of cardiovascular diseases and death, but the underlying mechanisms are insufficiently understood. Objective. To determine how aerobic fitness and muscular strength are associated with serum metabolome measures. Design, Setting, and Participants. This cross-sectional study included Finnish men receiving military refresher training from May 5, 2015, to November 28, 2015, representing partly overlapping groups of individuals with the lowest vs highest aerobic fitness and the lowest vs highest muscular strength. Data analyses were conducted from January 1, 2018, to May 31, 2019. Main Outcomes and Measures. The associations of aerobic fitness (determined with maximum oxygen consumption in milliliters per minute per kilogram, measured with maximal cycle ergometer test) and muscular strength (determined with a maximal strength test for lower extremities in kilograms) with 66 metabolome measures from fasting serum samples (nuclear magnetic resonance–based metabolomics) were analyzed. Results. Participants included 580 Finnish men (mean [SD] age, 26.1 [6.5] years). Including overlap between groups, there were 196 men in the lowest aerobic fitness group and 197 men in the highest aerobic fitness group as well as 196 men in the lowest muscular strength group and 197 men in the highest muscular strength group. Of 66 studied metabolome measures, 48 differed between high vs low aerobic fitness groups, including small very low-density lipoprotein (standardized median difference, −0.67; 95% CI, −0.83 to −0.49), large high-density lipoprotein (standardized median difference, 0.89; 95% CI, 0.69-1.15), total triglyceride levels (standardized median difference, −0.52; 95% CI, −0.65 to −0.34), isoleucine (standardized median difference, −0.37; 95% CI, −0.55 to −0.16), leucine (standardized median difference, −0.55; 95% CI, −0.72 to −0.34), phenylalanine (standardized median difference, −0.54; 95% CI, −0.71 to −0.32), glycerol (standardized median difference, −0.64; 95% CI, −0.81 to −0.48), and glycoprotein (standardized median difference, −0.78; 95% CI, −0.95 to −0.62) concentration, a high unsaturation degree of fatty acids (standardized median difference, 0.59; 95% CI, 0.42-0.81), and apolipoprotein B to apolipoprotein A1 ratio (standardized median difference, −0.88; 95% CI, −1.08 to −0.67). Adding aerobic fitness into the regression model after age, education, smoking, use of alcohol, and dietary factors accounted for more than an additional 5% of variation for 25 metabolome measures (R2 range, 5.01%-15.90% by measure). With these 2 criteria, maximal muscular strength was not associated with any metabolome measures. Aerobic fitness was associated with high large high-density lipoprotein particle concentration (R2, 14.97%; 95% CI, 10.65%-20.85%), low apolipoprotein B to apolipoprotein A1 ratio (R2, 14.49%; 95% CI, 10.58%-19.51%), and low glycoprotein concentration (R2, 15.90%; 95% CI, 11.22%-21.51%). Aerobic fitness was also associated with low very low-density lipoprotein, triglyceride, isoleucine, leucine, phenylalanine, glycerol, and glycoprotein concentrations and with a high unsaturation degree of fatty acids. Adjusting for recent physical activity influenced the results minimally. Adjusting for body fat percentage showed that some of the associations were mechanistically associated with body fat percentage. Conclusions and Relevance. This study provides data on the association of high aerobic fitness with underlying oxidative lipid metabolism associated with a reduction in cardiometabolic risk. High maximal muscular strength is not similarly associated with these benefits. ; peerReviewed
Healthy lifestyle behaviors including physical activity (PA) have been recognized to contribute positively to mental health. Most of the evidence on relationship between PA and mental health relies on self-reported PA results. Device-based measures on PA or sedentary behavior (SB) are less frequently used in mental health research. The present study aimed at examining the relationship between mental health and PA/SB measured by accelerometers in young Finnish men. The sample consisted of 409 men (mean age 28 ± 7 years), who participated in the military refresher training in Finland. Self-rated mental health was measured with Mental Health Inventory (MHI-5) and short Warwick-Edinburgh Mental Well-being Scale (SWEMWBS) measuring mental health both from the perspective of mental health problems and mental well-being. PA was measured with accelerometer from the perspective of light, moderate, vigorous, and total activity, as well as SB. Linear regression models and compositional analysis were applied. Age, education, marital status, employment status, BMI, alcohol use and smoking were used as covariates. Evidence on relationship between total PA (standardized regression coefficient 0.340; 95% CI 0.022–0.657, p = 0.036) and SB (standardized regression coefficient −0.340; 95% CI −0.657 to −0.022, p = 0.036) with symptoms of mental health problems was found after adjusting for age, education, marital and employment status. The relationship was marginally significant (p = 0.056) after adjusting also for BMI, alcohol use and smoking. No evidence on relationship between PA or SB and mental well-being was found, neither in standard linear regression analysis nor in compositional approach. In our sample of young adult men, PA seemed to have a stronger relationship with symptoms of mental health problems rather than with mental well-being. The findings lead to a conclusion that all PA per se may not be independently associated with mental well-being in young adult males and raise the question whether the domain of PA and its context play a critical role in these relationships. ; publishedVersion ; Peer reviewed
Healthy lifestyle behaviors including physical activity (PA) have been recognized to contribute positively to mental health. Most of the evidence on relationship between PA and mental health relies on self-reported PA results. Device-based measures on PA or sedentary behavior (SB) are less frequently used in mental health research. The present study aimed at examining the relationship between mental health and PA/SB measured by accelerometers in young Finnish men. The sample consisted of 409 men (mean age 28 ± 7 years), who participated in the military refresher training in Finland. Self-rated mental health was measured with Mental Health Inventory (MHI-5) and short Warwick-Edinburgh Mental Well-being Scale (SWEMWBS) measuring mental health both from the perspective of mental health problems and mental well-being. PA was measured with accelerometer from the perspective of light, moderate, vigorous, and total activity, as well as SB. Linear regression models and compositional analysis were applied. Age, education, marital status, employment status, BMI, alcohol use and smoking were used as covariates. Evidence on relationship between total PA (standardized regression coefficient 0.340; 95% CI 0.022–0.657, p = 0.036) and SB (standardized regression coefficient −0.340; 95% CI −0.657 to −0.022, p = 0.036) with symptoms of mental health problems was found after adjusting for age, education, marital and employment status. The relationship was marginally significant (p = 0.056) after adjusting also for BMI, alcohol use and smoking. No evidence on relationship between PA or SB and mental well-being was found, neither in standard linear regression analysis nor in compositional approach. In our sample of young adult men, PA seemed to have a stronger relationship with symptoms of mental health problems rather than with mental well-being. The findings lead to a conclusion that all PA per se may not be independently associated with mental well-being in young adult males and raise the question whether the domain of PA and its ...
The aim of the study was to examine whether sports participation (SP), engagement in competitive sports (CS), and the type of sport undertaken at the age of 12 are associated with the physical and mental components of health-related quality of life (HRQoL) in young adulthood. The data were collected using questionnaires prior to a compulsory military refresher training course in Finland. The sample consisted of 784 men (mean age 26 years). HRQoL was measured with RAND 36 and childhood SP with a series of questions. Data were analyzed with logistic regression. Higher frequency of SP, participation in district-level CS; performing team, endurance, or extreme sports; and playing yard games in childhood were after adjustments all associated with better HRQoL in early adulthood. The association was mainly found with the mental component, and to a lesser extent with the physical component, of HRQoL. Team (OR 1.43, CI 1.00–2.06) and extreme sports (OR 1.77, CI 1.19–2.63) were associated with better mental HRQoL, while playing yard games (OR 0.62, CI 0.44–0.89) reduced the likelihood for having low physical HRQoL. SP in childhood—in the forms of team or individual sports, but also as informal physical activity, such as playing yard games—is associated with HRQoL in young adulthood. ; peerReviewed
The aim of the study was to examine whether sports participation (SP), engagement in competitive sports (CS), and the type of sport undertaken at the age of 12 are associated with the physical and mental components of health-related quality of life (HRQoL) in young adulthood. The data were collected using questionnaires prior to a compulsory military refresher training course in Finland. The sample consisted of 784 men (mean age 26 years). HRQoL was measured with RAND 36 and childhood SP with a series of questions. Data were analyzed with logistic regression. Higher frequency of SP, participation in district-level CS; performing team, endurance, or extreme sports; and playing yard games in childhood were after adjustments all associated with better HRQoL in early adulthood. The association was mainly found with the mental component, and to a lesser extent with the physical component, of HRQoL. Team (OR 1.43, CI 1.00–2.06) and extreme sports (OR 1.77, CI 1.19–2.63) were associated with better mental HRQoL, while playing yard games (OR 0.62, CI 0.44–0.89) reduced the likelihood for having low physical HRQoL. SP in childhood—in the forms of team or individual sports, but also as informal physical activity, such as playing yard games—is associated with HRQoL in young adulthood.
The aim of the study was to examine whether sports participation (SP), engagement in competitive sports (CS), and the type of sport undertaken at the age of 12 are associated with the physical and mental components of health-related quality of life (HRQoL) in young adulthood. The data were collected using questionnaires prior to a compulsory military refresher training course in Finland. The sample consisted of 784 men (mean age 26 years). HRQoL was measured with RAND 36 and childhood SP with a series of questions. Data were analyzed with logistic regression. Higher frequency of SP, participation in district-level CS; performing team, endurance, or extreme sports; and playing yard games in childhood were after adjustments all associated with better HRQoL in early adulthood. The association was mainly found with the mental component, and to a lesser extent with the physical component, of HRQoL. Team (OR 1.43, CI 1.00–2.06) and extreme sports (OR 1.77, CI 1.19–2.63) were associated with better mental HRQoL, while playing yard games (OR 0.62, CI 0.44–0.89) reduced the likelihood for having low physical HRQoL. SP in childhood—in the forms of team or individual sports, but also as informal physical activity, such as playing yard games—is associated with HRQoL in young adulthood.
Background: In the military context, high levels of physiological and psychological stress together can compromise individual's ability to complete given duty or mission and increase dropout rates. The purpose of this study was to investigate if baseline physical fitness, body composition, hormonal and psychological factors could predict dropout from a 10-day intense winter military survival training. Methods: 69 conscripts volunteered to participate in the study. Physical fitness (muscle strength and power, muscle endurance, and aerobic fitness), body composition and hormonal variables (BDNF, testosterone, cortisol, SHBG, DHEAS, IGF-1) together with self-reported psychological factors (short five personality, hardiness, sense of coherence, stress, depression) were assessed prior the survival training. Results: During the survival training, 20 conscripts (29%) dropped out. Baseline aerobic fitness (hazard ratio, HR: 0.997, 95% CI: 0.994–0.999, p = 0.006) and serum cortisol (HR: 1.0006, 95% CI: 1.001–1.011, p = 0.017) predicted dropout in Cox regression model. Each 10 m increase in the 12 min running test decreased the risk for dropout by 3%. Conclusion: Although most of the physiological and psychological variables at the baseline did not predict dropout during a short-term winter survival military training, baseline information of aerobic fitness and serum cortisol concentration may be useful to target support for individuals at higher potential risk for dropout. ; peerReviewed
Physically demanding essential military tasks include load carriage, manual material handling and casualty evacuation. This narrative review characterizes the main physical attributes related to performance of these occupational tasks and reviews physical training intervention studies in military settings to improve performance in these military tasks. Load carriage performance requires both aerobic and neuromuscular fitness with greater emphasis on maximal strength and absolute maximal oxygen uptake, especially when carrying heavier loads. In manual material handling, maximal strength and power are strongly associated with discrete lifting, while muscular strength, muscular endurance and aerobic fitness are also associated with repetitive lifting performance. Maximal strength including grip strength, muscular endurance, absolute maximal oxygen uptake and anaerobic capacity are associated with casualty evacuation performance. The results of the present review particularly emphasize the role of muscular fitness in successful performance of the reviewed military occupational tasks. Training intervention studies indicate that load carriage performance can be effectively improved by combining strength, aerobic and specific load carriage training. Improvement in maximal lifting capacity can be achieved by strength training or combined strength and aerobic training, while strength and aerobic training alone, or their combination are effective in improving repetitive lifting, and carry tasks. Only a few studies are available for casualty evacuation and the results are inconclusive but may indicate benefits of strength or combined training. Moreover, emphasis on lower volume but higher intensity in combined training may be a feasible and effective mode to improve military occupational performance in recruits and active-duty soldiers. ; peerReviewed
Limited data are available regarding strength and endurance training adaptations to occupational physical performance during deployment. This study assessed acute training-induced changes in neuromuscular (electromyography; EMG) and metabolic (blood lactate, BLa) responses during a high-intensity military simulation test (MST), performed in the beginning (PRE) and at the end (POST) of a six-month crisis-management operation. MST time shortened (145 ± 21 vs. 129 ± 16 s, −10 ± 7%, p < 0.001) during the operation. Normalized muscle activity increased from PRE to POST in the hamstring muscles by 87 ± 146% (116 ± 52 vs. 195 ± 139%EMGMVC, p < 0.001) and in the quadriceps by 54 ± 81% (26 ± 8 vs. 40 ± 20%EMGMVC, p < 0.001). In addition, higher acute BLa values were measured after MST during POST. Changes in BLa and EMG suggested an increased neural input and metabolic rate during POST MST, likely leading to faster performance times at the end of the operation. High EMG values throughout the different phases of MST suggested that despite the anaerobic nature of the test, the soldiers were able to maintain their voluntary muscle activation level until the end of the test. This indicates only limited neural fatigue during the two-minute high-intensity military specific performance. While learning effect may explain some part of the improvement in the MST performance times, combined strength and endurance training three times per week may improve neuromuscular performance in occupationally relevant tasks. ; peerReviewed
