Overload occurs when the balance between external load and internal load is altered so that the body’s adaptive capacity is inadequate, resulting in manifestations of altered performance and injury and/or illness.
An understanding of the Overload Principle forms the foundation of how we calculate the weight loads, sets, and reps used to get the desired results we seek in each program. Increases in weight loads from one step to another must be performed carefully, and gradually. This pattern of increasing weight loads is called the” Step-Load Pattern”. Once the progression blocks and step-loading pattern have been set for the month’s training, these patterns can be linked together.
It is recommended that all individuals find 1 RM per exercise. The Repetition Maximum lifting 100% of as much weight as possible for the given exercise.
External vs. Internal Load & Recovery
Athletes respond individually to internal and external load; the result of which determines the magnitude of the loading stimulus experienced.
- External load is the work completed by the athlete during training and competition. External loads create physical, physiological, and psychosocial demands, which are affected by frequency, intensity, and duration of the activity, among other factors. Demands may be sport-specific.
- Internal loads are individual physical, physiological, and psychosocial characteristics that respond to an external load. Identical external loads may elicit considerably different internal loads in two athletes with different internal characteristics (e.g., age, sex, body composition, fitness, range of motion (ROM), history of a prior injury, psychosocial health). Internal loads vary over time, requiring ongoing monitoring.
- Recovery is a process with the goal of optimizing physical, physiological, and psychosocial adaptation to internal and external loads
That’s why monitoring the internal load of athletes has become an integral part of training programs, where the aim is always to help players adapt and improve.
How to Measure Internal Load
There are several measures used to monitor an athlete’s internal load. At the basic level, subjective measures include
- the RPE (Rate of Perceived Exertion) scale and
- Via wellness questionnaires.
These rely on the accuracy of athlete self-reporting.
Objective data can be found through athlete-monitoring technology which provides quantifiable internal load metrics including;
- tracking intensity through %HR Max, and
- TRIMP (Training Impulse): TRIMP quantifies Training Load in a single number and accumulates continuously. The rate of accumulation depends on the intensity of the drill/session and it does not decrease during recovery breaks.
Observing time spent in different Intensity Zones shows how hard players worked during a specific session.
Need to Measure Internal Load
Tracking the physiological impact of a training session on an individual athlete – or an entire team – gives individuals & coaches a quantifiable overview of how one or players are handling a session. It also shows whether a session is achieving the desired physiological results or needs to be tweaked.
This can be particularly useful when teams are implementing training periodization at various points in the season (tailoring sessions to help players peak at certain times during the season such as the playoffs).
Tracking external load data is valuable but can leave one with only half the information needed to make effective and informed training decisions and relay information to colleagues. The same person can have a very different reaction to the same exact session from one day to the next, depending on several circumstances (fatigue, recent training history, illness, non-competition stressors, etc). This isn’t immediately obvious without physiological insights.
Monitoring internal load can also inform future training decisions such as whether to push or hold back an individual and can help track individual player adaptations to training. In the case of a team, a player presenting higher internal load data compared to teammates during a standard external load session may indicate signs of fatigue or reduced fitness. In contrast, a player showing decreased internal load in the same session would indicate increased fitness and an ability to cope with the stress being placed on them.
With a combination of internal and external load data, an individual or trainer can decide on the training load.