To compare training load and energy expenditure during an 8-week military BT period among individuals having different fitness level using objective measurements in an authentic environment. Methods: Thirty-four voluntary male conscripts (age 19.1±0.3 years) were divided into three training groups (inactive, moderate, active) by their reported physical activity (PA) level evaluated by the International Physical Activity Questionnaire (IPAQ) prior to military service. Maximal oxygen uptake (VO2max) and heart rate (HR) were determined by maximal treadmill test in the beginning and after 4 and 7 weeks of BT. During BT, HR monitors and accelerometers were used to measure PA and energy expenditure. HR data were used to calculate the training load (TRIMP, training impulse) for each day, week and the whole BT period. Results: Training load of BT was comparable to training of competitive athletes at the highest level. The training groups differed (p<0.001-0.05) in terms of VO2max to each other (inactive 36±6, moderate 42±6, active 48±6 ml/kg/min). The conscripts in the inactive group were the most loaded during the study period (TRIMPinactive 12393±2989 vs. TRIMPmoderate 10252±1337, p<0.05 and TRIMPactive 8444±2051, p<0.01). The PA intensity of different military tasks during the BT period were low or moderate (<6MET). Conclusion: The remarkable training load during BT period is comparable to the training loads of professional athletes participating three weeks' cycling competition. The training load in basic training period was, however, primary due to duration of low intensity activities including only some high intensity military activities. In the future, measuring the training load during the military service is recommended in order to customize the physical training for conscripts regarding his/her fitness level as much as possible.

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, nonoverreached (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 and 8, which was not observed in OR (-1.1±18.2%, p>0.05). In OR, plantarflexion twitch contraction time increased between weeks 5 and 10 82.2±34.4% (p<0.01), which was not observed in NOR. No changes were observed in the H-reflex and V-wave responses in either of the groups. In conclusion, short term overreaching can also reduce the performance of the neuromuscular system, however, it seems to be more muscle than neural based. To avoid overreaching, more individualized periodization should be used during basic training.To enhance neuromuscular performance, maximal and explosive strength training should also be added into the basic training program.

Amino acids are thought to have a key role in the processes contributing to overreaching development through their metabolic properties and neuronal functions. In the present study, the effects of 10-week military training on the concentrations of 19 amino acids were investigated. Plasma amino acid concentrations were measured at rest from 53 healthy male conscripts on weeks 1, 4, 7, and 9 of their military service. Conscripts were classified as overreached and non-overreached. Overreaching classification was based on fulfilling at least three of five criteria: greater than 5% decrease in maximal oxygen uptake, increased rating perceived exertion (RPE), and decreased lactate-RPE ratio in submaximal marching test, admitting feeling overloaded and both increased scores in fatigue and decreased scores in vigor in the Profile of Mood States Adolescents. Eight conscripts (15%) were classified as overreached; their glutamine–glutamate ratio and alanine and arginine levels were significantly lower ( P < 0.05) and glutamate concentration significantly higher ( P < 0.05) in comparison to their non-overreached counterparts. The levels of arginine increased ( P < 0.05) and tryptophan ( P < 0.001) decreased in both groups throughout the study. The tyrosine concentration increased in non-overreached but, in contrast, remained at the same level in overreached individuals ( P < 0.05). The results suggest that alterations in the levels of three metabolically important amino acids, alanine, glutamate and arginine, and the possibly neuroactive tyrosine and tryptophan might explain some of the physical and psychological symptoms of overreaching. The present study also confirms the potential use of glutamine–glutamate ratio as a tool for detecting overreaching. Impact statement The diagnosis of overtraining syndrome and overreaching poses a great challenge. Military training aims at improving the physical performance of the conscripts, but an excessive training load could also lead to overreaching. This study of Finnish conscripts provides new insights into the pathophysiology of overreaching and overtraining through amino acids concentrations. In addition to confirming the possible use of plasma glutamine/glutamate concentration to indicate and predict overreaching, we made a novel finding, i.e. low alanine and arginine concentrations might have a role in performance decrement and fatigue related to overreaching. Moreover, this study is the first to show the possible association between amino acids with putative neuronal properties and overreaching. Thus, the present findings might help to detect and prevent overreaching and offer a reliable diagnostic approach. In order to avoid overreaching, military training should be planned more periodically and individually, especially during the first four weeks of military service.

SummaryStudy 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.Results: FFM decreased significantly in LF after 7 weeks of training (–3.0 ± 1.7%, p < 0.001), which was not observed in GF. Both GF (6.9 ± 4.6%, p < 0.01) and LF (5.7 ± 4.6%, p < 0.01) showed improved VO2max after 5 weeks, with no changes during the last 3 weeks. A main effect of training was observed in decreased leg press MVC (–7.3 ± 9.3%, F = 4.899, p < 0.05), with no between-group differences. V-wave was significantly lower in LF during 5 (–37.9%, p < 0.05) and 8 (–44.9%, p < 0.05) weeks.Conclusion: Poor development of the neuromuscular system during BT suggests that explosive and/or maximal strength training should be added to the BT protocol for all conscripts regardless of fitness level. In addition, individualized training periodization should be considered to optimize the training load.