How does our body react to such an abrupt stop to training? We tell you how we can put this loss into real numbers and figures and carry out a physical assessment during Quarantine.
Physical Activity during Quarantine
Physical Activity is “every movement of the body that makes muscles work and requires more energy than being at rest” (National Heart, Lung, and Blood Institute, 2020).
In relation to this, physical condition is the ability of a person to perform physical activity and/or physical exercise, and constitutes an integrated measure of all functions (musculoskeletal, cardio-respiratory, haemato-circulatory, endocrine-metabolic and psycho-neurological) and structures that intervene in physical activity and/or exercise (Ruiz et al., 2011).
Conversely, having poor physical condition could indicate a malfunction of one or more of these elements (Ruiz et al., 2011).
How can we measure Physical Activity?
The evidence points to:
- The role of developing motor competence skills (MC);
- The development of health-related physical fitness elements (HRPF);
- Physical Activity (PA); and
- Prevention of childhood obesity (Cattuzzo et al., 2016).
These authors developed a systematic review whose objective was to review the scientific evidence on the associations between CM and HRPF in children and adolescents (Cattuzzo et al., 2016).
The results show strong evidence indicating that CM development is inversely associated with body weight status and positively associated with cardio-expiratory fitness and musculoskeletal fitness in childhood and adolescence.
Therefore, interventions in motor competence and physical fitness should be promoted simultaneously in an environment appropriate for the development of general functional capacities (Cattuzzo et al., 2016).
On the other hand, in the systematic review of Gray et al., (2015) the relationship between time outdoors and physical activity, cardiorespiratory fitness, musculoskeletal fitness, sedentary behavior and the development of motor skills in children from 3 to 12 years old was explored.
As a result, consistent evidence is provided that children ages 3 to 12 who spend more time outside are more active and less sedentary.
High levels of physical inactivity and sedentary behavior are a global concern. As a consequence of a quarantined state, sedentary behaviors are more prevalent.
Detraining and Quarantine
Detraining (Mujika & Padilla, 2000a; 2000b) is “the partial or complete loss of training-induced adaptations in response to insufficient training stimulus”.
The characteristics of the detraining may be different depending on the duration of the stopping of training or insufficient training.
As a result, we find two types of detraining:
- Short Term: less than 4 weeks of insufficient training stimulus.
- Long Term: more than 4 weeks of insufficient training stimulus.
The main conclusions of these physical and physiological phenomena will be explained below (Mujika & Padilla, 2000a; 2000b)
Short-term cardiorespiratory detraining (Figure 1) is often characterized by a rapid decrease in VO2max in highly trained athletes, but a smaller reduction in newly trained individuals.
Due to this loss in cardiorespiratory fitness, the performance (endurance level) of trained athletes declines rapidly, while being kept up for at least 2 weeks in newly trained individuals.
Figure 1. Short-term cardiorespiratory detraining. Source: Mujika & Padilla (2000a).
When physical training is significantly reduced or stopped for a period of more than 4 weeks (figure 2), the VO2max of highly trained athletes decreases by 6-20%, but generally remains at above sedentary values.
In addition, long-term inactivity can promote a decrease in cardiac dimensions and breathing efficiency, affecting both VO2max and performance (endurance) of athletes and moderately trained individuals.
Figure 2. Long-term cardiorespiratory detraining. Source: Mujika & Padilla (2000b). /em>
From a metabolic point of view (figure 3), short-term training implies a greater dependence on carbohydrates as a source of fuel to work out muscles, as demonstrated by the increase in the respiratory exchange ratio (RER) and decreased muscle lipoprotein lipase activity.
The absorption of glucose throughout the body is reduced, due to a decrease in insulin sensitivity and a reduced content of muscle GLUT-4 transporter protein, both in athletes and in recently trained people.
Blood lactate levels at standardised submaximal intensities increase, the lactate threshold appears at a lower percentage of VO2max, and there is a base deficit that induces higher post-exercise acidosis.
Also, muscle glycogen levels drop rapidly.
Figure 3. Short-term metabolic detraining. Source: Mujika & Padilla (2000a).
Long-term metabolic detraining (Figure 4) is characterised by increased carbohydrate use and increased blood lactate concentration during sub-maximal exercise, resulting in accelerated onset of the lactate threshold which does still remain above control values in athletes.
Meanwhile, resting muscle glycogen levels return to baseline.
Figure 4. Long-term metabolic detraining. Source: Mujika & Padilla (2000b).
When focusing on muscular level (Figure 5), short-term detraining is characterized by a decrease in capillary density, an unchanged arterial-venous oxygen difference and a reduction in myoglobin levels, significant reductions in oxidative enzymatic activities resulting in reduced mitochondrial ATP production and unsystematic changes in glycolytic enzyme activities.</strong
The distribution of muscle fibre remains the same.
However, fiber cross-sectional area decreases in strength and athletes who partake in sprinting activities and newly endurance-trained individuals, while it might go up slightly in endurance athletes.
Although overall strength performance is easily retained for up to 4 weeks of inactivity, athletes’ eccentric strength and sport-specific power ability can suffer noticeable decreases.
Figure 5. Short-term muscle detraining. Source: Mujika & Padilla (2000a).
From a muscular perspective, insufficient long-term training (Figure 6) often results in a decrease in action provided by muscle capillary, a reduction in the arterial-venous oxygen difference, and a large decrease in oxidative enzyme activity, the latter two being directly related to long-term reduction in VO2max.
All previous muscle characteristics remain above sedentary values in the trained athlete, training-induced muscle adaptations of newly trained individuals return to pre-training conditions.
In endurance athletes, there may also be a decrease in the proportion of ST fibers and a large change from FTa to FTb fibers, but strength-trained athletes may show increased oxidative enzyme activity, the proportion of fibres and an overall decrease in fibre area.
Strength production decreases slowly and relative to decreased EMG activity. All these changes are also evident in the newly trained.
Figure 6. Long-term muscle detraining. Source: Mujika & Padilla (2000b).
Assessment of Physical Condition during Quarantine
The assessment of physical activity (PA) in the school and family units is relevant (Cossio-Bolaños, 2020).
In children and adolescents
In the elderly
Type of tests
The level of physical condition can be objectively evaluated by laboratory tests and field tests (Ruiz et al., 2011).
Laboratory tests have the advantage that they are carried out under very controlled conditions, however their use is limited when you want to assess physical condition in the family context (among other scenarios).
Field tests are a good alternative because of their easy execution, low financial requirements, no necessity for sophisticated technical equipment, as well as the time necessary to carry them out (Ruiz et al., 2011).
Next, a series of physical and motor competence assessment tests (which can be carried out mostly in the family or indoor environment) based on the evidence will be demonstrated and synthesised.
Functional Movement Screening™ (FMS)
The FMS™ is a system for detecting limitations in the fundamental movement patterns of the individual through seven tests (Deep Squat, Hurdle Step, In-Line Lunge, Shoulder Mobility Test, Active Straight Leg Raise, Trunk Stability Push-Up and Rotary Stability Test) that require a balance between mobility and stability, including neuromuscular and motor control (Héctor, 2015; Kraus, Schütz, Taylor & Doyscher, 2014).
How is this evaluation carried out?
From a practical point of view (figure 7), conditions are carried out 3 times, although the best test is the one that is ultimately evaluated (Kraus et al., 2014).
The total FMS score is the sum of the 7 scores, resulting in a maximum of 21 points.
A 4-point classification system is used to assess the quality of movement (Kraus et al., 2014):
- Value 3: correct movement pattern.
- Value 2: need for compensatory movements to solve the exercise.
- Value 1: inability to make the movement pattern.
- Value 0: presence of pain during the execution of the activity.
Figure 7. Functional Movement Screen (FMS) Test. Source: Mayer et al. (2015).
Finally, the functional capacity of this assessment system is shown in the review by Kraus et al., (2014).
Strength and fitness specialists can integrate the FMS as a low-cost, time-efficient detection tool as part of their monitoring tools.
It is, however, worth mentioning that its ability to predict sports performance is not supported by strong evidence.
The French national program “Bouge … Une priorité pour ta santé!” aims to assess the physical fitness of children and adolescents from 6 to 18 years of age in French schools (Vanhels et al., 2014).
The included physical fitness tests were chosen for their validity, reliability, low cost, and feasibility for all schools (Figure 8).
On the other hand, the characteristics of the BOUGE are summarized in the following practical points:
- Ease of understanding and execution by an inexperienced advisor.
- High understanding on the part of children and teenagers.
- Good reproducibility: allows schools to compare results.
- Inclusion of European standards associated with testing.
- Placement of children and adolescents in each grade of physical condition.
- Evaluation of the effects of an intervention and identification program on children and adolescents at risk of developing one or more diseases going into adulthood.
- Assimilation of the physical limitations of the child and adolescent, as well as the material, environmental and temporal limitations in a school establishment setting.
- Low administration time: 2h for a group of 20 students.
Assessment of 4 components of physical condition
- 800m sprint test.
- 20m Multi-stage fitness Test.
Strength (upper and lower limb).
- Ball throw test.
- Long jump test.
- Sprint test of 20m, 30m and 50m.
- Shoulder flexibility test.
Figure 8. BOUGE test. Source: Vanhels et al. (2014).
The present study describes the work carried out for the creation of the ALPHA-Fitness battery (figure 9) with the aim of evaluating the physical condition related to health in children and adolescents (Ruiz et al., 2011 ).
Figure 9. ALPHA-Fitness battery. Source: Ruiz et al. (2011).
The evaluation of physical health condition should be considered as an instrument that fosters and promotes the practice of physical activity and exercise (Ruiz et al., 2011).
The agonist-antagonist muscle strength ratio is commonly used for both injury prediction and performance testing.
In relation to this, Negrete, Hanney, Pabian &; Kolber (2013) examined the relationship between agonist-antagonist strength of the upper body using two simple field tests (timed push up/timed modified pull up) in recreationally active adults, and the establishment of the basis for reference standards going forward.
Figure 10. Ratio Push-Pull. Source: Negrete et al. (2013).
The jump assessment (Squat Jump, Counter-Movement Jump, Drop Jump, Single Hop and Triple Hop) is a functional measure that can be evaluated by means of different instruments:
Contact Platforms, Accelerometers, Infrared Cameras/Platforms, High Speed Cameras, Force Platforms and Mobile Applications (Sotelo, 2018).
Specifically, this tool uses the high-speed recording function of the IPhone 5 (120 fps), through which the vertical jump take-off and landing frames are used (Sotelo, 2018).
Figure 11. My Jump ©. Source: Balsalobre-Fernández, Glaister and Lockey (2015).
Specifically, the application has the following characteristics: (Sotelo, 2018):
- Low cost.
- Simple to use.
- Determination of flight time and height of the jump.
- Obtaining power through body mass.
- Control of Training and Functional Sports Re-education.
- Reliability and validity (compared to the measurements made by force platform).
- Ability to export data to an Excel spreadsheet.
- Unlimited number of users and trials/jumps.
- Linked to social networks to share data.
- Multiple language options.
Minute Burpee Test
The Burpee is an exercise used to measure or develop agility, coordination and cardiorespiratory endurance.
- 10” Burpee Test.
- 20” Burpee Test.
- 30” Burpee Test.
- 60” Burpee Test.
- 3‐Minute Burpee Test.
Figure 12. 3-Minute Burpee Test. Source: Podstawski et al. (2019).
On the other hand, Podstawski et al. (2019) developed international standards to assess strength-resistance through the3‐Minute Burpee Test (Figure 13).
The results reveal that this test can be implemented operationally to determine resistance-resistance in individuals of different age groups and different nationalities.
Figure 13. International Standards for the 3-Minute Burpee Test. Source: Podstawski et al. (2019).
20-m Shuttle Run Test (20mSRT)
At each stage, the required running speed increases, until the athlete can no longer complete the 20m distance in time and form after the audio signal (a beep) (2 consecutive times), or when stopped due to volitional fatigue.
This tool is the most widely used field test for the evaluation of cardiorespiratory fitness.
Therefore, Tomkinson et al. (2019), developed a systematic review whose objective was to clarify the international usefulness of the 20mSRT by synthesising the evidence that describes the variability, validity, reliability, feasibility, and interpretation of the measurement results.
- Valid, reliable, acceptable and feasible measure for the evaluation of cardiorespiratory fitness.
- Good functional ability marker.
- Favourable for the health of children and young people.
- Possible international monitoring tool to help better understand the health status of pediatric (child) population.
- National Heart, Lung, and Blood Institute (2020). ¿Qué es la actividad física? National Heart, Lung, and Blood Institute.
- Ruíz, J. R., España Romero, V., Castro Piñero, J., Artero, E. G., Ortega, F. B., Cuenca García, M.,… & Gutiérrez, A. (2011). Batería ALPHA-Fitness: test de campo para la evaluación de la condición física relacionada con la salud en niños y adolescentes. Nutrición Hospitalaria, 26(6), 1210-1214.
- Vanhelst, J., Béghin, L., Czaplicki, G., et al., Ulmer, Z. (2014). La condition physique des enfants et adolescents: comment la mesurer en milieu scolaire? L’exemple de la batterie BOUGE. Revue Médicale de Bruxelles.
- Cattuzzo M.T., dos Santos Henrique R., Re A.H.N., de Oliveira I.S., Melo B.M., de Sousa Moura M., de Araujo R.C., Stodden D. (2016) Journal of Science and Medicine in Sport, 19(2), 123-129.
- Gray, C., Gibbons, R., Larouche, R., Sandseter, E. B. H., Bienenstock, A., Brussoni, M.,… & Power, M. (2015). What is the relationship between outdoor time and physical activity, sedentary behaviour, and physical fitness in children? A systematic review. International Journal of Environmental Research and Public Health, 12(6), 6455-6474.
- Mujika, I., & Padilla, S. (2000a). Detraining: loss of training-induced physiological and performance adaptations. Part I. Sports Medicine, 30(2), 79-87.
- Mujika, I., & Padilla, S. (2000b). Detraining: loss of training-induced physiological and performance adaptations. Part II. Sports Medicine, 30(3), 145-154.
- Cossio-Bolaños, M. (2020). Actividad física en tiempos de cuarentena por el COVID-19 en niños y adolescentes. Revista Peruana de Ciencias de la Actividad Física y del Deporte, 7(2), 2-2.
- Camiña Fernández, F., Cancela Carral, J.Mª y Romo Pérez, V. (2001). La prescripción del ejercicio físico para personas mayores. Valores normativos de la condición física. Revista Internacional de Medicina y Ciencias de la Actividad Física y el Deporte, 1(2), 136-154.
- Héctor, J. (2015). Examinando la calidad de movimiento: Functional Movement Screening. PowerExplosive.
- Kraus, K., Schütz, E., Taylor, W. R., & Doyscher, R. (2014). Efficacy of the functional movement screen: a review. The Journal of Strength & Conditioning Research, 28(12), 3571-3584.
- Mayer, S. W., Queen, R. M., Taylor, D., Moorman III, C. T., Toth, A. P., Garrett Jr, W. E., & Butler, R. J. (2015). Functional testing differences in anterior cruciate ligament reconstruction patients released versus not released to return to sport. The American Journal of Sports Medicine, 43(7), 1648-1655.
- Negrete, R. J., Hanney, W. J., Pabian, P., & Kolber, M. J. (2013). Upper body push and pull strength ratio in recreationally active adults. International Journal of Sports Physical Therapy, 8(2), 138.
- Balsalobre-Fernández, C., Glaister, M. y Lockey, R. A. (2015). The validity and reliability of an iPhone app for measuring vertical jump performance. Journal of Sports Sciences, 33(15), 1574-1579
- Sotelo, I. (2018). My Jump ©: Mide tu salto. MundoEntrenamiento.
- Podstawski, R., Markowski, P., Clark, C. C., Choszcz, D., Ihász, F., Stojiljković, S., & Gronek, P. (2019). International Standards for the 3‐Minute Burpee Test: High‐Intensity Motor Performance. Journal of Human Kinetics, 69, 137.
- Tomkinson, G. R., Lang, J. J., Blanchard, J., Léger, L. A., & Tremblay, M. S. (2019). The 20-m shuttle run: assessment and interpretation of data in relation to youth aerobic fitness and health. Pediatric Exercise Science, 31(2), 152-163.
- How can I perform a Burpee correctly? Click here.
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