Resting hormone concentrations have been a topic of many studies and discussions. It has been suggested that conflicting results were, at least partly, because of a lack of standardisation in both the way overtraining was measured and in the hormone measurement protocols used. Results from the present study show that variability in resting hormone concentrations is also present within groups of NFO and OTS patients. The arguments for contradictory findings are not valid within this study where blood was drawn at the same time of day always after an overnight fast. However, the diurnal variation in cortisol cannot be ruled out with this protocol because tests are separated by 4 h. However, each test was done with the same protocol and timing so that the data were collected in a standardised manner. One possible reason why the cortisol levels do not show the same pattern as ACTH might be because of this diurnal variation. Therefore, it must be concluded that resting hormone concentrations are not sensitive enough, at least not to diagnose unexplained underperformance in athletes. It has been suggested that hormonal reactions to stress tests are more sensitive.1 11
Leg muscle pain, defined as “the intensity of hurt that a subject feel in his quadriceps muscles only” , was measured during the incremental test (at the end of each minute) and during the time to exhaustion tests (at the end of the warm-up and every 30 s) using the Cook scale . Standardized instructions for the scale were given to each subject before the warm-up. Briefly, subjects were asked to rate the feelings of pain specifically in their quadriceps and not to report other pains they may have experienced (e.g., seat discomfort). Subjects were also asked to not use this rating as an expression of perceived effort .
LSR, SBS, HV, NPA, JEI, UW and DS contributed to the conception and design of the study. LSR, SBS, HV and DS were responsible for the collection of the Generation 100 data in cooperation with colleagues at the Cardiac Exercise Research Group at the Norwegian University of Science and Technology, Norway. LSR, SBS and XT provided the data for analysis. LSR undertook the data analysis and drafted the manuscript. All authors provided critical insight and revisions to the manuscript. All authors read and approved the final version of the manuscript submitted for publication.
Thus, little is known about the effects of monitored vigorous exercise in elderly people. While significant benefits for basic motor tasks (such as balance and gait) can be achieved through different kinds of physical activity (i.e., stretching exercises, treadmill, Pilates, and strength and balance training), no conclusive relationship has been proven between its intensity and such improvements. Recently, Pau et al.  reported that spatiotemporal gait parameters and sit-to-stand performance significantly improve through vigorous (but not light) exercises, thus suggesting that higher levels of intensity might be more suitable in generally improving static and dynamic daily motor tasks.