Safety and Prevention of OveRTraining

Athletic training aims to increase and improve physical performance that is achieved through training overload combined with periods of rest and recovery. Overtraining syndrome (OTS) is associated with an imbalance between training and recovery. The symptoms associated with OTS vary between individuals and may reflect parasympathetic and/or sympathetic nervous system alterations as well as endocrine irregularities. The prevalence is not known, but it is usually reported among endurance athletes, such as cyclists, distance runners and triathletes. It appears that OTS represents a systemic inflammatory process with diffuse effects on the neurohormonal axis affecting host immunology and mood. Previous works, showed that cell-free DNA (cf-DNA) is correlated with the severity of excessive exercise-induced inflammation as well as with trauma and stroke severity suggesting that it might be used as a potential clinical marker for athletes with overtraining syndrome. Oxidative stress indices can be determined non-invasively and may reflect inflammatory responses after training suggesting that they could be used as clinical markers for the diagnosis of OTS. However, there are no available biomarkers to aid towards the diagnosis and/or prevention of OTS, except that of the persistence of unexplained underperformance despite an extensive recovery of the athlete. Therefore, the purpose of this study is to evaluate the potential of cf-DNA and selected oxidative stress variables as diagnostic biomarkers of OTS.

A total number of 15 elite-level runners (both male and female) and 80-100 soccer players (both male and female) will participate in the study.The day when participants (runners) will arrive at the lab early in the morning, after an overnight fast. They will have their blood pressure and orthostatic heart rate measured and they will also provide a blood sample. Immediately after participants' body composition will be assessed by dual energy X-ray absorptiometry (DXA). Then, they will perform the Meeusen test providing a second blood sample immediately after the test. During the subsequent 4-hour resting period, the participants followed by assessment of joint mobility, delayed onset of muscle soreness, flexibility and vertical jump performance after that lower limb peak torque by isokinetic dynamometer. A second Meeusen test will take place after the resting period with blood sampling post-testing. Then, participants will have a 3-hour rest, after which they will visit the lab again in order to perform the running economy testing protocol and a maximal lactate steady state test. Finally, participants will complete POMS-, quality of sleep- and symptomatology-related questionnaires and will be taught on how to complete dietary recalls. Over the subsequent 12-month period participants will provide the investigator with a detailed report of their training plan and a symptomatology questionnaire every month. These measurements take place for all participants in two different periods, in transitional period/baseline and in middle season (berore tha main race). If someone of participants manifest the symptoms of overtraining, they perform the protocol of measurements again. The day when participants (soccer players) will arrive at the lab early in the morning, after an overnight fast. They will have their blood pressure and orthostatic heart rate measured and they will also provide a blood sample. Immediately after participants' body composition will be assessed by dual energy X-ray absorptiometry (DXA). The participants followed by assessment of joint mobility, delayed onset of muscle soreness, flexibility and vertical jump performance after that lower limb peak torque by isokinetic dynamometer. After resting, they will measurement the maximum oxygen uptake in stress test on the aisle. The next days, in football players take place in field tests, will measure the Speed in 10, 30 meters, Yo-Yo IE2 (Intermittent Endurance 2), Yo-Yo IR2 (Intermittent Recovery 2) and Repeated Sprint Ability (RSA). Finally, participants (soccer players) will complete POMS-, quality of sleep- and symptomatology-related questionnaires and will be taught on how to complete dietary recalls.These measurements take place for all participants in two different periods, in transitional period/baseline and in middle season (berore tha main race). If someone of participants manifest the symptoms of overtraining, they perform the protocol again.

Eligibility Criteria:
Inclusion Criteria for Runners:

Participants:

* should be long-distance runners, marathon runners, 5 km and 10 km runners.
* should be able to provide the daily training plan and a 7-day dietary recall every month.
* should be considered elite level runners.
* should be free of musculoskeletal injuries for at least one year before the study.

Inclusion Criteria for Soccer Players:

Participants:

* should be elite soccer players.
* should be able to provide the daily training plan and a 7-day dietary recall.
* should be participated in matches.
* should be free of musculoskeletal injuries for at least one year before the study.

Exclusion Criteria (both Runners and Soccer Players):

If participants:

* do not adhere to rules of the study.
* have a recent history of illness or injury .
* do not participate in competitive training.