Pilot study: Training load in athletes

To improve sport performance, regular exercise or training is required,
together with a gradual increase in training load. This increase in training
load leads to *functional overreaching* (F-OR). And with sufficient rest, this
F-OR leads to adaptations and improved sport performance, sometimes referred to
as *super compensations*. Athletes should, however, be aware to avoid *non-
functional overreaching* (NF-OR). Non-functional overreaching leads to
temporary under performance and with insufficient it can even lead to
overtraining (OT) and long lasting underperformance. Overtraining is
long-lasting underperformance with additional mood swings and physical
problems. About 60% of all athletes has been overtrained at one time in his/her
sport career.
Monitoring training load allows athletes to determine whether functional
adaptation takes place, whilst minimizing the risk of non-functional
overreaching. This can be done by either assessing performance on a certain
task (like a time trial), or monitoring physiological stress via changes in
heart rate (variability), lactate or hormone levels.
Many researchers try to find markers that can distinguish functional from
non-functional overreaching. This is done in practice (for example during a
training camp) or in a controlled setting (for example wit adjusted training
protocols and lab measurements). The protocols used for these kinds of studies
differ between the different researchers. While a more standardized approach
would be advised. The advantage of a standardized protocol is that the
different studies can be compared. And a standardized protocol would help
future researchers to induce overreaching in athletes in a controlled and safe
way. Therefore, it is important to design a protocol that induces overreaching
in athletes in a controlled and safe way. With this protocol, athletes will
experience underperformance for a while, but after recovery they will be fine
again.

The main objective of this study is to evaluate whether our protocol results in
non-functional overreaching in athletes in a controlled and safe way

A randomized, parallel design with a training period with increased volume and
intensity of 4 weeks. Time trials directly before and after this training
period and a recovery period and another time trial after the training period.
The overreaching or control intervention will be randomly divided between the
participants.

The intervention consists of a 4 week training period with increased
volume/intensity. Logbooks are filled in during this period. Training data
(heart rate, distance, duration) will be monitored using watches. Participants
will be tested prior to this period and after this period with time trials.
Before the time trial they answer a POMS questionnaire and after the time trial
they will grade the exercise intensity on a Borg scale.

Each participant has to visit the University four times (one time for
information and 3 times for a time trial). Logbooks are handed out at
information day. These logbooks are filled in during the 4 weeks of training.
Risks and discomfort are small. Athletes are used to perform maximal exercise,
which makes the time trials an additional average intensive training workout.
The overreaching period consists of a higher training volume and intensity then
athletes* average training program, this probably leads to fatigue and
temporary underperformance. But with sufficient recovery afterwards, this
should not cause long-lasting problems.
Because there is a risk (though very small) of overtraining, athletes will be
monitored. After every week of training, athletes will be called and a few
points will be checked: morning heart rate, (quality of) sleep, accomplishment
of the training protocol, and POMS questionnaire. If these data suggest that
the athlete is at risk for overtraining, he or she will be adviced to stop with
the study.
When there is doubt, the medical supervisor will contact the athlete.