0000000000043550
AUTHOR
Jukka Huovinen
Serum sex-hormone binding globulin and cortisol concentrations are associated with overreaching during strenuous military training
The purpose was (a) to study the effect of an 8-week Finnish military basic training period (BT) on physical fitness, body composition, mood state, and serum biochemical parameters among new conscripts; (b) to determine the incidence of overreaching (OR); and (c) to evaluate whether initial levels or training responses differ between OR and noOR subjects. Fifty-seven males (19.7 ± 0.3 years) were evaluated before and during BT. Overreaching subjects had to fulfill 3 of 5 criteria: decreased aerobic physical fitness (VO2max), increased rating of perceived exertion (RPE) in 45-minute submaximal test at 70% of VO2max or sick absence from these tests, increased somatic or emotional symptoms of …
Neuromuscular Performance and Hormonal Profile During Military Training and Subsequent Recovery Period
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 concen…
Effects of military basic training on VO2max, body composition, muscle strength and neural responses in conscripts of different aerobic condition
Summary Study aim: The purpose of this study was to evaluate neuromuscular adaptations in conscripts with different fitness levels (VO2max) during 8 weeks of military basic training (BT). Material and methods: Twenty-four male conscripts (18–21 years) were divided into two groups (Good Fitness [GF] and Low fitness [LF]) based on their VO2max at the beginning of BT. Body mass (BM), fat free mass (FFM) and Fat% were measured after 2, 4, and 7 weeks of training. VO2max, maximal isometric leg press force (MVC), H-reflex (Hmax/Mmax) at rest and V-wave (V/Mmax) during maximal isometric plantarflexion were measured from the soleus muscle at the beginning, after 5, and after 8 weeks of training. Re…
Neuromuscular Performance and Hormonal Profile During Military Training and Subsequent Recovery Period.
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 concen…
Cardiac autonomic function reveals adaptation to military training
Abstract The last 4 weeks of basic military training are very stressful. We tested the hypothesis that changes in cardiac autonomic function during this period are associated with changes in maximal oxygen uptake and/or serum hormonal concentrations in male conscripts (n=22). Cardiac vagal autonomic function was assessed by measuring the high-frequency (0.15–0.4 Hz) spectral power of R–R intervals. Maximal oxygen uptake ([Vdot]O2max) and basal serum testosterone concentration were measured at the beginning and end of the period. Individual changes in vagally mediated high-frequency power (range −15% to +25%) correlated (r=0.73, P=0.001) with changes in [Vdot]O2max (range −9% to +6%) and cha…
Relationship between heart rate variability and the serum testosterone-to-cortisol ratio during military service
Abstract The autonomic nervous system and circulating hormones control a stress reaction through a complex interaction. We tested the hypothesis that changes in cardiac vagal regulation may be positively associated with the serum testosterone-to-cortisol ratio during the first week of military service in 24 conscripts aged 19.0±0.3 years. Cardiac autonomic function was assessed by measuring high-frequency (HF: 0.15–0.4 Hz) and low-frequency (LF: 0.04–0.15 Hz) power spectral indices of R-R intervals during supine rest and during a controlled standing condition (5 min for both) from the second to the seventh mornings at the beginning of military service. Blood samples were collected to analys…
Effects of 10 weeks of military training on neuromuscular function in non-overreached and overreached conscripts
The purpose of the study was to examine how military training influences neuromuscular function in non-overreached and overreached conscripts. A total of 24 male conscripts participated in the study (8 weeks basic training + 2 weeks specialized training). All measurements were conducted during weeks 1, 5, 8 and 10. After the training period, non-overreached (NOR, n = 16) and overreached (OR, n = 8) groups were compared. Isometric maximal forces (bench press, elbow flexion and knee extension), single twitch (plantar flexors), H-reflex, M-wave (Hmax/Mmax) and V-wave (V/Mmax) (soleus) were measured. In knee extension, force production increased in NOR by 22.5 ± 20.5% (p 0.01) between weeks 1 …
Serum Sex Hormone–Binding Globulin and Cortisol Concentrations are Associated With Overreaching During Strenuous Military Training
The purpose was (a) to study the effect of an 8-week Finnish military basic training period (BT) on physical fitness, body composition, mood state, and serum biochemical parameters among new conscripts; (b) to determine the incidence of overreaching (OR); and (c) to evaluate whether initial levels or training responses differ between OR and noOR subjects. Fifty-seven males (19.7 ± 0.3 years) were evaluated before and during BT. Overreaching subjects had to fulfill 3 of 5 criteria: decreased aerobic physical fitness (VO2max), increased rating of perceived exertion (RPE) in 45-minute submaximal test at 70% of VO2max or sick absence from these tests, increased somatic or emotional symptoms of …