We train athletes everyday. But how do we know whether the athletes attending the training program are adopting to the program? How do we assess fatigue? How do we know whether they are overreaching or productive ? How do we know whether they have recovered from the previous session?
Therefore there needs to be some some form of quantifiable metrics to measure the athletes performance at any given point of time.
In Badminton rallies are of short duration and it involves greater amount of energy. A 60-80 min hard session will atleast need hours to recover before going in for the next session. So we need to quantify each training session and progressively increase the load. Without quantifying the load both the coach and the athlete will be left in a no mans land and sudden increase in loading greatly increases the chances of injury . Measuring the training loads will make the sessions smoother and progressively increasing the training loads gradually improves the players fitness and health. So there are practically two types of load , Internal load and External load.
INTERNAL LOAD
PERCEPTION OF EFFORT ( RPE) and SESSION RATING OF PERCEIVED EFFORT (sRPE):
The rating of perceived exertion (RPE) is one of the most common means of assessing internal load. The athletes can monitor their physiological stress during exercise and provide information regarding their perceived effort post training or competition. The Borg 15-point RPE scale was originally developed to monitor the amount of exertion.
As RPE is purely objective, these readings depend on the cognitive feelings of the athletes and also the athletes might tend to manipulate these values.
Session RPE method of quantifying training load involves multiplying the athlete’s RPE (on a 1–10 scale) by the duration of the session (in minutes). SRPE tool is far more practical for coaches with many athletes and busy schedules. SRPE has been shown by numerous sources to represent a valid quantification of training load. This method is best suited to monitor loading status in Strength and Power training.
TRAINING IMPULSE (TRIMP):
This Method was originally proposed by Banister and uses the athlete’s HR response ( Hear rate monitors )along with the training duration to yield a score for that session.
TRIMP = D * (∆ HR Ratio) eb( 1 ) [1 is the ∆HR Ratio given below]
D = duration of the training session
b = 1.67 for females and 1.92 for males
e = 2.71828
1 ---> ∆HR Ratio = (HRexercise 2 HRrest)/(HRmax 2 HRrest)
HRrest is the average heart rate during rest, HRexercise is the average heart rate during exercise. (Source: National Strength and Conditioning association)
A lower TRIMP score is equated with a lower internal training load of the athlete (i.e., the training session was relatively “easier” for the athlete), and a higher TRIMP score is equated with a higher internal training load for the athlete (i.e., the training session was relatively “harder” for the athlete).
Later, Garcia-Ramos proposed a advanced model of TRIMP based on the addition of partial impulse units within a session. This model is well suited for interval training sessions where work and rest functionality are being taken into consideration.
TRIMP (Gacia-Ramos) : -6.348+1.086 TRIMP +0.266 HRsd +0.013 Nint
TRIMP : Normal Standard value found using Banister Trimp model
HRsd : Standard deviation of Heart rate
Nint : Number of Recorded Time interval
(Source: Conference paper titled “A modified method of TRIMP calculation to quantify training load in elite swimmers")
For Endurance training Banisters TRIMP model can be used to monitor loading status. A simple Heart rate monitor(Hear rate chest strap) can be used to get those HR values needed for the equation.
BLOOD LACTATE CONCENTRATION:
Blood lactate concentration is sensitive to changes in exercise intensity and duration. Lactate concentration coupled with sRPE at submaximal workload (70-95% of Maximum heart rate) can be used to evaluate internal load. In a research paper titled “Evalution of sports specific training programme in Badminton players”, 1993 the author suggests to maintain a blood lactate level of 3.9 mMol/l and 6.2 mMol/l during training with and without shuttlecork respectively so as to not overreach(Lactate accumulation resulting in acidosis) which might cause muscle injury or hinder recovery .
BIOCHEMICAL ASSESSMENTS:
Creatine Kinase(CK) and Urea are expensive to measure and already known. Urea as the end product of protein breakdown reflects metabolic strain. CK levels increase especially after eccentric muscle contractions. Therefore CK is widely used as a marker of training induces muscle strain and recovery. Urea, uric acid and CK were found be to be higher in players after an intensive training session in Badminton (Physiological analysis to quantify training load in Badminton,1997) . However these measures can be costly, time consuming and impractical in an applied environment.
PSYCHOLOGICAL QUESTIONNAIRES (POMS, REST Q SPORT):
Questionnaires can be a relatively simple and inexpensive means of determining the training load. However, both questionnaires rely on subjective information. It is possible for athletes to manipulate data and underestimate/overestimate training load. Some of the well-known Questionnaires are,
Profile Of Mood States (POMS)
Recovery-Stress Questionnaire for Athletes (REST-Q-Sport)
Daily Analysis Of Life Demand For Athletes (DALDA)
SLEEP:
Sleep loss or deprivation can have significant effects on performance, motivation, perception of effort and cognition as well as numerous other biological functions. The use of simple diaries indicating hours of sleep can be useful. Slow Wave Sleep(SWS) also known as deep sleep is the time when the muscles repair and grow. So theoretically, enhancing SWS enhances recovery. Numerous wrist based smart watches are available in the market that could give you a number of the quality of sleep.
EXTERNAL LOAD
To gain an understanding of external training load, a number of technologies are available to athletes and coaches. GPS is one such emerging technology that has been inducted into every sports utilities that could measure distance, speed, velocity and acceleration. But higher the velocity of movement, lower the GPS reliability. So External load is very sports specific and it all depends on the variables that influences the performance of the athlete. Neuromuscular functional tests can also be used as an external load measure. A simple jump test or a sprint performance can be used to measure the loading status.
Best monitoring methods as per NSCA is given below:
Quantifying Power and strength training : sRPE
Quantifying Endurance Training : sRPE and TRIMP
Source(National strength and conditioning Association)
MONITORING ATHLETE RESPONSE TO TRAINING WITH HEART RATE VARIABILITY
Heart rate variability is in the trend for nearly 40 years to measure/evaluate the effectiveness of Autonomic nervous system . It gives us a way to measure how physiological stress, training load, and fatigue are effecting and how our bodies may be recovering from a particular session. Heart rate variability is noninvasive and inexpensive tool that can be used to quantify internal physiology
There is an increasing interest in monitoring the status of the autonomic nervous system (ANS) via measures of heart rate (HR), including the level and variability of HR at rest and following exercise during exercise and during recovery after exercise.
While the collection of (beat-by-beat) HR was initially only possible with expensive laboratory-based electrocardiograph recorders, the recent availability of valid and portable recorders such as heart-rate monitors specifically-designed systems or smart phone applications has substantially boosted the use of HRV monitoring in the field. Example : Elite HRV is a mobile application that connects to your heart rate chest strap and displays a score that relates to your recovery status/Stress levels.
Conclusions from the study “Measuring training status with HR measures: do roads lead to Rome?” are given below.
5 minutes of Resting HRV(supine position) with the last 60s of a submaximal Exercise HR are the most useful monitoring variables.
Resting HRV(Morning after waking up) be collected very frequently to examine both chronic (3-4 times as week) and acute responses to training.
In another research paper titled “Relationship between Autonomic Markers of Heart Rate and Subjective Indicators of Recovery Status in Male, Elite Badminton Players” the author concludes, that subjective indicators of recovery status influence HRV and HRR measures obtained in a competitive badminton environment and should therefore be incorporated in protocols that evaluate these ANS-related parameters.
CONCLUSION
So by quantifying the training load using any of the load monitoring methods we can keep an eye on the progress of the athlete reducing the onset of stress/injury. There are several technologies and sensors that could provide reliable data (with Coefficient of variability) that the coaches could use to monitor training load.
On the Recovery part it will be better if we start every session by asking the athletes to fill in the basic questionnaires(POMS/REST-Q-Sport) and end the session by asking them to fill in the sRPE. These two combined with HR related indices ( Data from Heart rate monitors) will give a good insight into the loading status of the athletes. Also continuous readings of the Heart Rate Variablity(HRV) helps us to track both the loading and recovery. There are several other factors like climate, hydration and time that could influence these readings and the coaches/support staff should try to add these in the final loading score/rating.
