Quantifying training load series – Importance of understanding the concept of an individualization

Accepting tennis athlete as an individual and creating the specific approach to his/her training and development

Basically, the goal of any monitored practice program would be increasing the chances for the optimal performance, but reducing the risk of nonfunctional overreaching, overtraining, illness, and injury. Monitoring and quantifying the training dosage (load) would be the most important aspect for any practice program to begin with, as it directly influences the physical, psychological, technical, and tactical element of the training. This series will explain the methods of measuring how the athlete responds physiologically and psychologically to the training loads and based on this information how the training dosage should be modified. The relationship between the training load dosage and how does the athlete response to it determines the efficiency of the training performance as the outcome.

WHAT IS Load, strain and stress

The stress in sports is adopted from physics where stress is introduced in mechanics by Hook’s Law (Robert Hook, 1660). Hooke’s law is the law of elasticity and states that deformation of the object or change of its size is directly proportional to the force or load that causes the changes. Upon load removal the object returns to its original shape and size. 

Hooke’s law is expressed in terms of load, stress and strain. Stress is the force within a material in the object that is created due to the externally applied force (load). Strain is the object deformation produced by stress. For relatively small stresses, stress is proportional to strain.

By Hook’s Law: 

  1. the load that acts on an object (in his case spring, but in our case athlete’s body, organs and tissues) causes the proportional change in shape (or body state, such as homeostasis) which is termed as a strain
  2. This change in shape is accompanied by an energetic charge within the object (strain in his case, body in ours) which is termed as stress.  
  3. When the load is removed, the object returns to its original size. The energy (force) stored in the object (stress) is making this possible. 

When the load is removed, the object returns to its original state as long as the stress limit (point of extreme strain) of the object is not reached. Beyond that point, object is prone to the nonreversible deformation or breakage. The critical load for the object is the point which causes the change in the structure of the object which is not returned to its original state after the load was removed. The full recovery of the structure is expected as soon as the load is removed, but if the load was too large and therefore creating large energetic charge in the object beyond the stress point, then the object would experience the fully deformation. 

Before reaching the critical load, strain and stress are directly proportional so the terms can be used as interchangeable. Beyond this point, stress is the crucial variable as strain (change in length of the object) and stress (energetic state in the object with the purpose of returning the structures of the object in the initial length) are no more interchangeable the deformation occurs. 

When monitoring and managing the training process, the important aspect to consider is the relationship between the load of the single training session and how does that load affect the training process in terms of adaptability and recovery.

Fatigue that occurs during a training session is a normal response of the athlete to the training. Within the next few hours, the athlete should begin the recovery process which can last to a day or two depending on the training load that was put on him. If fully recovered, the athlete should adapt to the previous stress which should led to the improvement in the performance. If there is not enough time for the recovery or if the athlete or coach haven’t matched the values of the training stress with the recovery, then the acute fatigue condition could lead into much serious maladaptive physiological and psychological disturbances. 


Individualization is one of the main requirements of the success of the training. Training does depend on the expertise and the experience of the coaches and the supporting team but the athletes and their needs are the priority to be understood, measured and implement into the training process. Each athlete has their specific physiological and psychological attributes and characteristics that HAS to be a starting point of the development of the training program. Depending on the athlete’s needs, learning abilities, demands, potentials etc, a coach can design the successful program which will balance the training loads and the athlete’s positive responses to that load. The art of coaching is not to apply the successful training program that fits the needs of the elite player, but to create the program that would respond to the needs of their own players. 

The beginning point of the design of the training program is the detailed analysis of the athlete’s physiological and psychological abilities, which will give the coach insight into the athlete’s work capacity. The training capacity can be determined by:

Biological age: 

The biological age is an accurate indicator of the athlete’s physical potential as, comparing to the chronological age, indicates the true physical state of the athlete despite the age. Athletes who are more physically mature, can be stronger, faster, and even have better learning and attention capabilities, no matter of their chronological age. During their training process, higher loads can be applied as they have higher delaying rates of fatigue due to their physical strength. Even their personality changes making them more responsible and attentive. 

Training age: 

Training age is defined by the number of years that an athlete is included in the sports activity and it’s a parameter that determines the difference of the specialized programs in the technical, tactical and physical elements of the training. Experienced athletes have ability to participate in the more specialized program as they have developed a substantial training base plan already, compared to the inexperienced ones.

Training history: 

An athlete’s training history influences the training ability. An athlete who has undertaken training before is more likely to have developed the physical basics of the sport and is ready for the more challenging training efforts, compared with an athlete who didn’t train before.

Health status: 

Injured athlete will have a reduced work capacity and will not be able to respond to the higher training loads. Most of the athletes that were injured, should pass the psychological readiness tests for the coach to determine if they are ready for the challenging training efforts again. Monitoring of the physiological and psychological health status is to determine the athlete’s readiness to perform and the level of the appropriate training load.

Lifestyle stress and the recovery: 

There are many factors that influence the training load, level of stress and the recovery process. Monitoring the athlete and his/her training process can identify these factors, quantify them and include them in managing of the training process. The obvious factors as volume, intensity, duration, frequency of exercise affect the training and competition load, but they shouldn’t be taken as the main factors as the athlete interacts with certain type of environment on everyday bases. Environmental factors, outside training factors are referred as life load factors (life stress, relationship with environment, educational stress etc). 

The training dosage consists of the training, competition load and lifestyle loads. Lifestyle loads are any type of physiological and psychological stress coming from the everyday non training environment, as heavy involvement in school, work, or family activities can affect the athlete’s ability to respond to the training load. The total training and life stress need to be considered to understand in full what could affect the athlete’s performance. 

Individualization of the Training Load

The ability to adapt to a training load depends on the individual’s physiological and psychological capacity. The coach must address the athlete’s needs and capacities by developing an individualized program rather then mimicking the training plans of elite athletes which will not result in the high performance but can result in developing chronic injuries and burnouts. Individualization of the training program requires detailed assessments and observations of the athlete’s physical and psychological characteristics and their strengths and weaknesses. These results, the complete profile of an athlete, should be the guidelines for creating the training program designed for the high performance as from this position, the training progression is measurable and possible to monitor. Periodic individualized physical and psychological testing would enable coaches to design and monitor more specific and successful training plans. 

Next blog: Physical and metabolical test and assessments

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.