Strength Training: Difference between revisions

No edit summary
No edit summary
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* increased bone mineral density
* increased bone mineral density
* and improved body composition.
* and improved body composition.
It also has been shown to improve function in postcoronary patients and chronic obstructive pulmonary disease (COPD) patients, as well as to reduce discomfort in people with low back pain and arthritis. In addition, strength training has proved effective for decreasing depression and for reducing the risk of metabolic syndrome, cardiovascular disease, and premature all-cause mortality.<ref>Westcott W. [https://journals.lww.com/acsm-healthfitness/fulltext/2009/07000/acsm_strength_training_guidelines__role_in_body.7.aspx ACSM strength training guidelines: Role in body composition and health enhancement.] ACSM's Health & Fitness Journal. 2009 Jul 1;13(4):14-22.</ref>
It also has been shown to improve function in postcoronary patients (by offers greater development of muscular strength, endurance, and mass) and chronic obstructive pulmonary disease (COPD) patients, as well as to reduce discomfort in people with low back pain and arthritis. In addition, strength training has proved effective for decreasing depression and for reducing the risk of metabolic syndrome, cardiovascular disease, and premature all-cause mortality.<ref>Westcott W. [https://journals.lww.com/acsm-healthfitness/fulltext/2009/07000/acsm_strength_training_guidelines__role_in_body.7.aspx ACSM strength training guidelines: Role in body composition and health enhancement.] ACSM's Health & Fitness Journal. 2009 Jul 1;13(4):14-22.</ref>


== Criterion measures ==
== Criterion measures ==
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'''1RM ( One repetition maximum):'''
'''1RM ( One repetition maximum):'''


There is an inverse relationship between the amount of weight lifted and the number of repetitions. So the strength training literature is often based on a percentage of one repetition maximum (1RM) in order to define the intensity of training by exercise physiologists, rehabilitation specialists, and strength coaches
There is an inverse relationship between the amount of weight lifted and the number of repetitions. So the strength training literature is often based on a percentage of one-repetition maximum (1RM) in order to define the individualize intensity of training to ensure participant's safety.
 
1 RM is defined as the weight load that the subject could successfully raise before the last weight load that he could not raise.<ref>Neto JC, Cedin L, Dato CC, Bertucci DR, de Andrade Perez SE, Baldissera V. [https://www.asep.org/asep/asep/JEPonlineJUNE2015_Neto.pdf A single session of testing for one repetition maximum (1RM) with eight exercises is trustworthy.] J Exerc Physiol Online. 2015 Jun 1;18:74-81.</ref>
 
1 RM test is done of only one exercise per day or made at different times and intervals higher than 24 hrs in order to avoid possible neural fatigue. For instance, 1RM testing on chest press, leg press, lat pull down, triceps push down, knee extension, seated row, and biceps curl at different intervals. It is considered the gold standard for assessing muscle strength in non-laboratory situations.
 
Based on 1 RM intensity of resistance exercise are determined to ensure safety( Haslam et al found intra-arterial blood pressures during weight lifting in cardiac patients to be within a clinically acceptable range at 40% and 60% of 1 RM).<ref name=":1">American Heart Association Journal. Resistance Exercise in Individuals With and Without Cardiovascular Disease. Available from: https://www.ahajournals.org/doi/full/10.1161/01.cir.101.7.828. [Last accessed: 26-05-2020]
</ref>
 
It can be either calculated directly using maximal testing or indirectly using submaximal estimation methods. There are various formulas to calculate 1 RM via submaximal estimation metho. It is preferred as it is a safer and quicker method for those participants with co-morbidities and beginners.


== Evidences ==
== Evidences ==
resistance exercises and chronic diseases
There are various guidelines  (majorly, American College of Sports and Medicine and American Herat Association) for the prescription of resistance exercises in a healthy population and population with different co-morbidities and different age groups.


resistance and older population
=== Resistance exercises and chronic diseases ===
Abdominal obesity, insulin resistance, hypertension, and dyslipidemia are major factors for chronic diseases like cardiovascular disease. Although the mechanisms for improvement may be different, both aerobic endurance exercise and resistance training appear to have similar effects on bone mineral density, glucose tolerance, and insulin sensitivity.
 
Resistance training assists the body in expending calories via an increase in lean body mass and basal metabolism rate helping in maintaining body composition.
 
==== Cardiovascular diseases (CVD) ====
Blood Pressure Lowering Treatment Trialists Collaboration, 2014 reported that the magnitude of resistance exercise induced reductions in SBP (5–6 mmHg) and DBP (3–4 mmHg) are associated with an 18% reduction of major cardiovascular events.
 
A study was done by Mcleod et al, 2019 recommended low-to moderate intensity resistance exercise training(RET)  (30–69% of 1RM) is safe and effective even in individuals with CVD or at risk for developing CVD.<ref name=":2">Mcleod JC, Stokes T, Phillips SM. [https://www.frontiersin.org/articles/10.3389/fphys.2019.00645/full Resistance exercise training as a primary countermeasure to age-related chronic disease]. Frontiers in physiology. 2019 Jun 6;10:645.</ref>
 
According to the AHA, a comprehensive resistance-training program of 8 to 10 exercises for 20 to 30 minutes with an intensity of ≈50±10% of 1 RM with a minimum of 2 days per week and, if time permits, progress to 3 days per week is recommended. Exercise need to be done at a comfortably hard level (13 to 15 on the RPE [rating of perceived exertion]) and without valsalva maneuver. Progession of exercise can be done by increasing 5 % of weight if the participant can comfortably lift the weight for up to 12 to 15 repetitions. If the participant cannot complete the minimum number of repetitions (8 or 10) using good technique, the weight should be reduced.<ref name=":1" />
 
==== Type 2 Diabetes ====
American Diabetes Association, 2014  has reported lifestyle modifications (i.e diet and exercise) were associated with a greater reduction on glycemic control  than medication with more emphasis on aerobic exercise training. However there are other studies showing benefits of resistance exercise on glycemic control.
 
There is a contradictory result showing the level of intensity of resistance exercises in glycemic control. But the study done by Mcleod et al. 2019, recommends inclusion of general whole body resistance exercises twice in week in routine without worrying about exercise intensity.<ref name=":2" />
 
==== Cancer ====
There is a role for resistance exercise in reducing cancer risk, cancer recurrence, cancer mortality, and improving prognosis during adjuvant therapies. In breast<ref>Wanchai A, Armer JM. [https://www.sciencedirect.com/science/article/pii/S2352013218303351 Effects of weight-lifting or resistance exercise on breast cancer-related lymphedema: a systematic review.] International journal of nursing sciences. 2019 Jan 10;6(1):92-8.</ref> and prostate cancer,resistance exercise has been apparent. Further work need to be done to address the optimal dose, intensity, and mechanisms specific to reisitance exercise induced benefits to cancer.<ref name=":2" />
 
=== Resistance and older population ===
with increase in age, there comes various


resistance and mental health
resistance and mental health
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*[[Strength training in prepubescents]]
*[[Strength training in prepubescents]]
*[http://antoinedl.com/fichiers/public/ACSM-guidelines-2014.pdf (2014) ACSM's guideline for exercise testing and prescription].
*[http://antoinedl.com/fichiers/public/ACSM-guidelines-2014.pdf (2014) ACSM's guideline for exercise testing and prescription].
*[https://www.ahajournals.org/doi/full/10.1161/01.cir.101.7.828 Resistance Exercise in Individuals With and Without Cardiovascular Disease]-American Heart Association
== References  ==
== References  ==



Revision as of 10:31, 26 May 2020

Introduction[edit | edit source]

Physical activity is defined here as any bodily movement produced by the contraction of skeletal muscle that increases energy expenditure. Exercise is defined as the physical activity that is planned, structured, and repetitive. Resistance exercise is one of the modalities of exercise chosen for physical conditioning.[1]Resistance training is any activity that causes muscles to contract against an external force. It is also known as strengthening exercises. It comes under anaerobic exercise which means it produces energy via anaerobic metabolism.[2]

Resistance exercise can serve as a potent stimulus to the musculoskeletal system necessary to bring about gains in muscle size, strength, endurance, and power. Since the goal of resistance training is to progressively overload the musculoskeletal system, weight machines, dumbbells, and barbells are usually used as resistance with that own body weight can be used as resistance.[2]

Effect of resistance training[edit | edit source]

Strength training stimulates a variety of positive adaptations that enhance both physical and mental health. Studies have shown that regular progressive resistance training develops

  • the strength and size of muscles
  • increases bone mass from young male athletes to older women.
  • in addition, resistance exercise might be even more beneficial than aerobic exercise for fat loss.[2]

Resistance exercise has produced beneficial outcomes for numerous physiological factors, including

  • increased blood glucose utilization
  • reduced resting blood pressure
  • improved blood lipid profiles
  • enhanced vascular condition
  • increased gastrointestinal transit speed
  • increased bone mineral density
  • and improved body composition.

It also has been shown to improve function in postcoronary patients (by offers greater development of muscular strength, endurance, and mass) and chronic obstructive pulmonary disease (COPD) patients, as well as to reduce discomfort in people with low back pain and arthritis. In addition, strength training has proved effective for decreasing depression and for reducing the risk of metabolic syndrome, cardiovascular disease, and premature all-cause mortality.[3]

Criterion measures[edit | edit source]

There are various guidelines for prescribing progressive resistance exercise training which is person-centered i.e based upon age and health conditions. Before involving in any progressive resistance exercises, t is very important to do pre-participation health screening to ensure exercise training can be safely initiated. It is also important to do exercise testing used for diagnostic (i.e., identify abnormal physiologic responses), prognostic (i.e., identify adverse events), and therapeutic (i.e., gauge impact of a given intervention) purposes as well as for physical activity counseling and to design an exercise prescription.

1RM ( One repetition maximum):

There is an inverse relationship between the amount of weight lifted and the number of repetitions. So the strength training literature is often based on a percentage of one-repetition maximum (1RM) in order to define the individualize intensity of training to ensure participant's safety.

1 RM is defined as the weight load that the subject could successfully raise before the last weight load that he could not raise.[4]

1 RM test is done of only one exercise per day or made at different times and intervals higher than 24 hrs in order to avoid possible neural fatigue. For instance, 1RM testing on chest press, leg press, lat pull down, triceps push down, knee extension, seated row, and biceps curl at different intervals. It is considered the gold standard for assessing muscle strength in non-laboratory situations.

Based on 1 RM intensity of resistance exercise are determined to ensure safety( Haslam et al found intra-arterial blood pressures during weight lifting in cardiac patients to be within a clinically acceptable range at 40% and 60% of 1 RM).[5]

It can be either calculated directly using maximal testing or indirectly using submaximal estimation methods. There are various formulas to calculate 1 RM via submaximal estimation metho. It is preferred as it is a safer and quicker method for those participants with co-morbidities and beginners.

Evidences[edit | edit source]

There are various guidelines (majorly, American College of Sports and Medicine and American Herat Association) for the prescription of resistance exercises in a healthy population and population with different co-morbidities and different age groups.

Resistance exercises and chronic diseases[edit | edit source]

Abdominal obesity, insulin resistance, hypertension, and dyslipidemia are major factors for chronic diseases like cardiovascular disease. Although the mechanisms for improvement may be different, both aerobic endurance exercise and resistance training appear to have similar effects on bone mineral density, glucose tolerance, and insulin sensitivity.

Resistance training assists the body in expending calories via an increase in lean body mass and basal metabolism rate helping in maintaining body composition.

Cardiovascular diseases (CVD)[edit | edit source]

Blood Pressure Lowering Treatment Trialists Collaboration, 2014 reported that the magnitude of resistance exercise induced reductions in SBP (5–6 mmHg) and DBP (3–4 mmHg) are associated with an 18% reduction of major cardiovascular events.

A study was done by Mcleod et al, 2019 recommended low-to moderate intensity resistance exercise training(RET) (30–69% of 1RM) is safe and effective even in individuals with CVD or at risk for developing CVD.[6]

According to the AHA, a comprehensive resistance-training program of 8 to 10 exercises for 20 to 30 minutes with an intensity of ≈50±10% of 1 RM with a minimum of 2 days per week and, if time permits, progress to 3 days per week is recommended. Exercise need to be done at a comfortably hard level (13 to 15 on the RPE [rating of perceived exertion]) and without valsalva maneuver. Progession of exercise can be done by increasing 5 % of weight if the participant can comfortably lift the weight for up to 12 to 15 repetitions. If the participant cannot complete the minimum number of repetitions (8 or 10) using good technique, the weight should be reduced.[5]

Type 2 Diabetes[edit | edit source]

American Diabetes Association, 2014 has reported lifestyle modifications (i.e diet and exercise) were associated with a greater reduction on glycemic control than medication with more emphasis on aerobic exercise training. However there are other studies showing benefits of resistance exercise on glycemic control.

There is a contradictory result showing the level of intensity of resistance exercises in glycemic control. But the study done by Mcleod et al. 2019, recommends inclusion of general whole body resistance exercises twice in week in routine without worrying about exercise intensity.[6]

Cancer[edit | edit source]

There is a role for resistance exercise in reducing cancer risk, cancer recurrence, cancer mortality, and improving prognosis during adjuvant therapies. In breast[7] and prostate cancer,resistance exercise has been apparent. Further work need to be done to address the optimal dose, intensity, and mechanisms specific to reisitance exercise induced benefits to cancer.[6]

Resistance and older population[edit | edit source]

with increase in age, there comes various

resistance and mental health

resistance exercise in trained athelets

Resources[edit | edit source]

References[edit | edit source]

  1. Mcleod JC, Stokes T, Phillips SM. Resistance exercise training as a primary countermeasure to age-related chronic disease. Frontiers in physiology. 2019 Jun 6;10:645.
  2. 2.0 2.1 2.2 Sundell J. Resistance training is an effective tool against metabolic and frailty syndromes. Advances in preventive medicine. 2011;2011.
  3. Westcott W. ACSM strength training guidelines: Role in body composition and health enhancement. ACSM's Health & Fitness Journal. 2009 Jul 1;13(4):14-22.
  4. Neto JC, Cedin L, Dato CC, Bertucci DR, de Andrade Perez SE, Baldissera V. A single session of testing for one repetition maximum (1RM) with eight exercises is trustworthy. J Exerc Physiol Online. 2015 Jun 1;18:74-81.
  5. 5.0 5.1 American Heart Association Journal. Resistance Exercise in Individuals With and Without Cardiovascular Disease. Available from: https://www.ahajournals.org/doi/full/10.1161/01.cir.101.7.828. [Last accessed: 26-05-2020]
  6. 6.0 6.1 6.2 Mcleod JC, Stokes T, Phillips SM. Resistance exercise training as a primary countermeasure to age-related chronic disease. Frontiers in physiology. 2019 Jun 6;10:645.
  7. Wanchai A, Armer JM. Effects of weight-lifting or resistance exercise on breast cancer-related lymphedema: a systematic review. International journal of nursing sciences. 2019 Jan 10;6(1):92-8.