Physical inactivity is associated with a significantly large number of health problems, such as cardio-cerebrovascular disease, metabolic disease, musculoskeletal disorders, and other neurodegenerative conditions.
In contrast, physical activity has been well studied and documented for its beneficial effects on overall health conditions. Cardiovascular, strength, and flexibility training has attracted most of the scientific research attention regarding the positive impact on health.
Before a participant can start the strength exercises, it is important to be familiar with all the different aspects of strength training—for example, basic concepts, benefits and risks, contraindications, and necessary modifications for use by diverse populations.
How We Get Stronger
The development and build-up of muscle strength depend on structural alteration, physiological modification, and neural adaptation. All systems work together to increase the cross-sectional muscle area and enhance actin-myosin cross-bridging – allowing for the generation of more significant force.
A strong correlation exists between the cross-sectional muscle area and force production capabilities, which suggests that muscular hypertrophy is a key element of strength development. Though, in many cases, strength development can be achieved without the occurrence of any hypertrophic responses.
Neurological adaptations include the muscles’ ability to increase motor unit recruitment, firing frequency, and motor coordination, which lead to optimal use of existing muscle mass.
Forms of Resistance Training
The term strength training describes all the exercise approaches that require the muscles’ ability to generate force.
This is a form of strength training that uses the participant’s own body weight as the source of resistance. Such activities include:
- Back extension
This form of exercise is useful in untrained individuals to provide a careful training routine. However, the trainee’s bodyweight limits the force that can be produced for any exercise, and beyond such point, progressive overload can only be practically imposed by changing sets, repetitions, and frequency.
Resistance bands offer greater and controlled resistance development in training compared to bodyweight exercises. Also, these bands are made of elastic material, which allows an individual to load and increase a wide range of body movements. The bands can be used for therapeutic, warm-up, cool-down, and other rehabilitative purposes. However, it has been suggested that bands are less effective for the long-term development of strength and muscle mass.
In a study from 2015, 117 older adults were assigned into 2 groups; one group was assigned to resistance band training and the other group was assigned to cognitive training. Results indicated that those assigned to six months of resistance band exercise displayed significant improvements in physical function.
Weight training machines
Weight machines are designed to deliver resistance training, usually in a seated or lying down position, which, ultimately, may not be functional for people in a wheelchair or with other impaired physical abilities. In addition, due to the lack of axial loading, it is unlikely to increase bone mineral density.
One particular advantage of the weight machines is that movement is constrained by their design, which allows motor learning and mastering of the movement to occur.
Regarding the design of the weight machines, large and multi-joint movement patterns (leg-press, chest-press, shoulder-press, seated row, or pull-down) are more desired than single-joint movement patterns (biceps curl and triceps extension).
Dumbbells and kettlebells
Dumbbells are useful tools for delivering introductory, accessory, and rehabilitative activities. For example, in physiotherapy settings, dumbbells are used to strengthen the rotator cuff after a shoulder injury. Also, dumbbells can be used as very low-weight resistance for trainees.
Kettlebells, similar to dumbbells, are used to add loading weight on the body during exercise practice. The unique spherical shape with a semicircular handle at one end can be used for overhead movements.
Barbell training is considered the highest level of resistance and performance training and exhibits advantages over other types of resistance training. This type of strength training offers important workout qualities, such as a complete range of motion with ergonomic loading in the movement allowed to stress and stimulate a large volume of muscle involvement.
This form of training offers movement patterns to load multi-joints at a large and precise volume and can also impose more potent training stress than weight machines or dumbbells/kettlebells. An EMG study showed that the barbell squat significantly increased muscle activation in the gastrocnemius, biceps femoris, and vastus medialis compared to muscle activation in weight machine training.
Adequate barbell training for the general population mainly involves standing exercises. Standing exercises promote and increase the axial load and enhance bone mineral density. Also, balance is practiced during standing exercises.