Skeletal Muscles, Strength Training & Nutrition.

Skeletal muscles: did you know that if you don’t use them, you lose them!

Strength training: what is it?

Strength training is often referred to as weight-training, however, it is not limited to just that. Resistance training is any exercise which gets your muscles working against an opposing force or weight, this could be against your own body weight or against external weights. Resistance training is often also called strength training because it challenges and promotes strength in muscles. It is important for improving skeletal muscle strength, endurance and maintaining bone health with regards to bone mineral density (BMD).

The main strength training types include:

● Muscle endurance: our muscles’ ability to perform repetitive contractions for an extended period of time. High reps using light weights or body resistance are usually exercises which help increase muscle endurance

● Muscle hypertrophy: refers to the increase and growth of muscle cells in size; this type of strength training usually consists of lifting moderate to heavy weights to stimulate muscle hypertrophy

● Circuit training: these exercises usually focus on cycling through a range of exercises with little-no rest in between, often works full body strength

● Maximum muscle strength: exercises to increase maximum strength usually consist of low reps (2-6) and heavy weights. Often utilised for those experienced exercisers who have mastered their form

● Explosive power: this type of training integrates both power and speed, often common for improving ability to perform explosive movements in sports among athletes.

What is the recommendation and what counts as strength/ resistance training?

Effective strength training exercises are recommended at least twice a week.

The aim is to work all main muscles 2-3 times a week with at least 48 hour recovery between sessions to allow time for muscle to repair, recover and adapt. Examples of resistance training include the use of resistance bands, lifting free weights (including dumbbells, barbells and kettlebells), utilising weight machines and using one’s own body weight, for example; pull-ups, squats or push-ups.

Doing more resistance activity in everyday life also counts! Like carrying bags or wearing a rucksack while walking, digging, gardening; using a wheelbarrow in the garden and anything else which involves lifting or carrying a heavier object to what you’re used to, is a good step. However, a regular, structured resistance training routine will bring the most benefits and have minimal injury risk when performed correctly. A structured strength training programme will also improve these everyday activities.

Effective resistance training: what is it?

In order for resistance training to be effective and have a consistent, positive impact, it needs to be structured using the ‘reps, sets, rest’ principal. Repetitions (reps) is the number of times each exercise is repeated in a set. The set refers to the group of repetitions performed of the exercise without resting. Rest is required between each set, the rest period varies depending on intensity/ difficulty of exercise, however usually it is 1-2 minutes.

For progression, the intensity would need to be monitored 3-6 weekly, and progressed if the exercise becomes too easy. This is to ensure strength is improving constantly. One can progress by increasing reps, sets or resistance (e.g. increase weight). Optimal benefits can be achieved by performing 3-4 sets for each exercise with a rest period of 1-2 mins between each set.

Resistance training should feel slightly challenging, especially during the progression stage. It should feel like the muscles are working, however, it should never hurt. Therefore, it would be a medical alert if one does feel sharp or sudden pain in muscles or joints, the exercise should then be stopped immediately and first aid treatment should be seeked. Muscle recovery is an important factor for muscle development, a good rule of thumb is to rest each muscle group for ~48 hours before working the same muscle group again; this helps to maximise muscle gains in size and strength.

Technique, body positioning and breathing are all important aspects of resistance training, these will help get the most out of training and would be more effective in reducing/ avoiding injuries.

Exercises should be performed in a controlled way for both the lifting (effort) and lowering (relaxing) part of the exercise, breathing is important for mind-muscle connection, it’s important to focus on the exercise to make the most of it.

At lifting: Breathe out

At lowering: Breathe in

Studies suggest that muscle activation (mind-muscle connection) is increased when there is a focus on the muscle being worked (Calatayud et al., 2015; Schoenfeld and Contreras, 2016).

What is DOMS and how to prevent/ reduce it?

DOMS is an abbreviation of ‘delayed onset muscle soreness’, it usually occurs as soon as 6-8 hours following exercise and often peaks around 48 hours. However, everybody is different and this varies to each individual. DOMS is a product of inflammation caused by microtrauma in connective muscle tissue. The symptoms are usually normal for most people following resistance training, they are most common when first starting an exercise program, when progressing a program or performing new exercises.

During the recovery period, it is important to still remain active; this is called ‘active recovery’. Active recovery basically means whilst the muscles that have been trained are recovering, participation in movement is still maintained. Active recovery and participation in gentle movements on rest days; such as walking instead of avoiding activity, helps reduce and ease the symptoms of DOMS and will help with adaptation of muscles/ muscle recovery. DOMS can be avoided by not overdoing exercise sessions and progressing weights gradually instead of suddenly. The good news is that DOMS is not damaging to health and is a sign of muscles adapting to training.

Why is resistance training important, and why should you include it into your training program?

There are multiple benefits to us increasing/ maintaining skeletal muscles by participation in strength training, below are just some of the main reasons why we should:

1 . Supports metabolism and weight management: Helps increase muscle-to-fat ratio.

Resistance training increases metabolism by increasing the muscles activity level for up to 72 hours post strength-training exercises, this means that our muscles use more energy with resistance training, even while at rest/ during sleep (MacKenzie-Shalders et al., 2020; Burt et al., 2014).

Metabolism is more efficient in muscle mass than in fat mass. Overtime, if following an effective, progressive regime, the muscle mass in our body may increase. More muscle requires more energy to maintain it, around 25kcals per kilogram per day, therefore, more energy is used each day, even while we rest or sleep (McMurray et al., 2014; Aristizabal et al., 2015).

2 . Promotes stronger bones and reduces risk of osteoporosis. Helps prevent falls/ bone fractures/ injuries.

Strength training plays a very important part in bone development. Exercises which are weight-bearing put a temporary stress on bones, this then sends a message to bone-building cells which promotes rebuilding of stronger bones. In turn, this helps reduce the risk of osteoporosis (brittle bones), bone fractures and injuries due to falls, especially with age (Rowe et al., 2022; Beck et al., 2017; Sozen et al., 2017). Studies have also shown strength training to be effective in improving quality of life and lessening symptoms/ pain from arthritis (Sieczkwska et al., 2020).

Older people with weaker muscles, slower reactions and poor balance due to inactivity are more likely to have reduced mobility and increased number of falls, as well as developing conditions such as sarcopenia (muscle wasting) or osteoporosis (brittle bones). This is particaulary prevelant in pre-menopausal and menopausal women due to the reduction of hormones such as estrogen.

Bone fractures: costs the NHS £1.1billion each year and less than 50% of the people affected go back to their own homes, increased risk with age!

42% of individuals who fall with fractures have persisting pain that doesn’t go away. Vertebrae fractures often heal in a flattened or wedge shape causing height loss and curved spine (kyphosis) which causes further health issues such as trouble breathing, abdominal pain and lowers self-esteem. Hip fractures often lead to long term disability, increased fragility and there is an extreme risk of death, often, people have to go into assisted living.

These predictable and tragic outcomes can be prevented if skeletal muscle and strength training is maintained and addressed throughout life!

3 . Improves muscular strength and promotes posture, mobility, flexibility & balance

Participating in regular resistance/ strength exercise can help make everyday activities easier (such as climbing stairs, carrying heavy bags and children) (Thomas and Burns, 2016).

Range of movement (ROM) can be increased by regular strength training, as long as the exercise is completed in full ROM. This also increases the body’s flexibility and mobility, which in turn supports a healthy posture and balance (Pallares et al., 2021; Schoenfeld and Girgis, 2020).

Additionally, strength training has been shown to benefit athletes in sports related to speed, power and strength, and due to its benefits on preserving lean muscle mass, it may also help endurance athletes (Thomas & Burns, 2016).

Individuals with weaker muscles often have lower ROM and reduced flexibility (Leite et al., 2017). Without resistance training, muscle mass (and bone mass) peaks at around ~30 years of age. After this, muscle mass starts to decline, unless the body is signalled otherwise, i.e. to maintain or increase. Studies have shown approximately 50% muscle fibres are lost between the age of 50 to 80 (Faulkner et al., 2007).

Therefore, it is important to maintain a strength training program throughout our life!

If we don’t use it, we lose it!

4 . Reduces abdominal fat and overall body fat percentage

Abdominal fat can be linked to an increased risk of chronic diseases such as heart diseases, type 2 diabetes, non-alcoholic fatty liver disease and certain types of cancers (Mutsert et al., 2018; Nam et al., 2020; Silveira et al., 2020; Xu et al., 2018).

Studies have shown strength training can help increase lean body mass, reduce abdominal fat and total body fat percentage (Yarizadeh et al., 202; Ihalainen et al., 2019). Muscle is more dense than fat tissue in the body, therefore, muscle takes up less space in the body for the same weight.

The more muscle you build, the leaner you will appear, therefore you could reduce waist measurements even if that is not apparent on the scales. Resistance training combined with a healthy balanced diet can help us preserve metabolically active muscle tissue and maintain healthy body composition (the muscle to fat balance in the body).

5 . Improves heart health and helps reduce risk of other chronic diseases

Studies have shown that regular strength- training can lead to similar improvements in blood sugar regulation as cardiovascular exercise, it also helps manage or prevent chronic diseases such as cholesterol, high blood pressure, other heart diseases and type 2 diabetes (Mcleod et al., 2019).

6 . Helps improve mood & brain health

Participation in strength-training exercises can be protective to age-related cognitive decline. Studies have shown there are significant improvements in cognitive function including; processing speed, memory and executive function in older adults who participate in strength training compared to those who do not. It has also been shown that resistance training interventions in older adults are effective in reducing frailty and cognitive impairment (Yoon and Song, 2018; Li et al., 2018; Mavros et al., 2016).

Resistance exercise also has various neuro-protective benefits; these include improving blood flow, reducing inflammation, activating memory and learning functions via increasing the concentration of brain-derived neurotrophic factor (BDNF) plasma (Wilke et al., 2019; Pereira et al., 2018; Chupel et al., 2017) .

There have been studies to show significant benefits of strength training to positive mental health; reduced anxiety, depressive symptoms and improved mood by promoting the release of mood-boosting endorphins; the so-called happy hormones (Gordon et al., 2020; Gordon et al., 2017; Strickland and Smith, 2014).

Skeletal muscles and Nutrition

Skeletal muscle acts as a nutrient sensor; it senses protein, and the efficacy at which it does that decreases as we age (Rasmussen, 2018). This is why it is harder to build muscle with older age and there is also a decrease in hormones. As we’ve already learned, as we age, there is also a rapid decrease in muscle mass and with that comes many other factors which may increase our risk of many diseases that affect our health, wellbeing and quality of life.

As ever, even more so, as we age, it becomes extremely important to participate in regular strength training.

It is important to support skeletal muscular health not just with the correct training but also the correct nutrition. When we train our muscles, the muscle fibres become slightly torn and this requires recovery in order to build more muscle/ adapt to new, increased strength.

Therefore, it is essential that recovery is supported with a good, nutritious diet. As we know, protein is the building blocks of life; from the embryonic stage, through to birth into childhood and adulthood. Protein is essential for maintaining the growth and repair of our muscle cells and tissues, and for a healthy development and function throughout life. Amino acids are the molecule chains that make up protein and these are important in increasing muscle syntheses (Mitchell et al., 2016).

We should be filling our diets with enough protein if we are to build healthy strong working muscles. A recommended dietary allowance (RDA) for protein consumption is 0.8g per kilogram of weight per day, this is reflective of the minimum amount of protein that is required for us to meet amino acid requirements and to prevent muscle mass loss (Antonio et al., 2014; Carbone & Pasiakos, 2019).

The source of protein is important; get most of your protein from plants if possible as they are cleaner and healthier. Examples are legumes and whole grains such as lentils, beans, peas, tofu, tempeh, nuts and seeds such almonds, hemp seeds, flaxseeds and chia seeds. Upgrade your sources of animal protein to more seafoods, crustaceans, poultry (chicken, turkey, duck), some eggs and dairy products and some unprocessed red meat (beef, lamb, mutton, goat) preferably lean meat.

Furthermore, a diet rich in nutrients will also support a healthy body and hence muscle and bone health. It is imperative to not cut out any food groups out of our diet, as this can lead to nutrient deficiencies and affect our health and can lead to muscle loss (sarcopenia).

As we know all food nutrients (macro and micronutrients) are required for health, even more so, for maintaining muscle and bone health.

Carbohydrates: will provide our body with energy- fuel for our muscles

Protein: supports the growth & repair of muscle cells and tissues,- supports growth & strength of working muscles

Vegetables & Fruits: Provides our body with essential vitamins, minerals & powerful antioxidants which supports normal hormone and body functions.

Food sources of protein includes meat, fish, dairy, beans, nuts and seeds.

Studies show there is a 30% increased risk of total bone fractures in vegans compared to meat-eaters, pescatarians and lacto-ovo-vegetarians. This may be due to the suboptimal intake of multiple nutrients; particularly protein, B-carotene, vitamin A, B12, D, K2, zinc, selenium, iodine and calcium; this is especially prevalent in people with low BMI. A healthy body weight will help optimise bone strength (Norris, J., 2021).

Overall, our body consists of organs, muscles and bone. They are all interlinked; each determine our overall health and wellbeing and it is crucial that the health of all these components are optimal. We should not compensate the health of one component with the other. The most effective way to improve our overall health is to commit to regular, safe, strength training and cardiovascular training, supported by a healthy, nutritious, balanced diet and looking after our mental health by taking the time out to relax and reflect.

As shown in this article, maintaining skeletal muscle has many benefits to our health with regards to disease prevention, bone health and well-being. This becomes especially more important as we age; if we don’t use it; we lose it; so we better use it!

References

Antonio et al., 2014 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4022420/

Aristizabal et al., 2015 https://pubmed.ncbi.nlm.nih.gov/25293431/

Beck et al., 2017 https://pubmed.ncbi.nlm.nih.gov/27840033/

Benedetto et al., 2018 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6323511/

Better Health https://www.betterhealth.vic.gov.au/health/healthyliving/resistance-training-health-benefits

Blaauw et al., 2013 https://www.researchgate.net/profile/Bert-Blaauw/publication/258830648_Mechanisms_Modulating_Skeletal_Muscle_Phenotype/links/5a04ab2ca6fdcceda02d45d4/Mechanisms-Modulating-Skeletal-Muscle-Phenotype.pdf

Bone health www.vegansociety.com/nutrition

Burt et al., 2014 https://pubmed.ncbi.nlm.nih.gov/23566074/

https://veganhealth.org/research/bone-fractures-among-u-k-vegans-implications-and-recommendations/

Calatayud et al., 2015 https://link.springer.com/article/10.1007/s00421-015-3305-7?platform=hootsuite

Carbone and Pasiakos, 2019 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6566799/