By Performance Spine and Sports Medicine
Many factors are involved in how the body changes structurally and functionally through resistance training to become stronger and more efficient. Many of the factors involved in initial changes in strength are purely psycho-neural, meaning that most initial gains can be attributed to changes in the nervous system allowing the body to move more efficiently and properly. You become more coordinated in the movement that you are trying to do allowing you to perform the movement properly and with more strength.
Factors include:
More efficient neural recruitment patterns
Increased central nervous system activation
Improved motor unit coordination
Lowered neural inhibitory reflexes
Inhibition of GTO
Through simply practicing a movement the body becomes better and stronger at that movement. When trying a certain exercise for the first time the body may not even be using the right muscles to perform the movement making the outcome weak and awkward while expending a good amount of energy, while with practice the body will learn to utilize the correct muscle groups to perform the movement and actually be able to utilize less energy to perform the movement stronger and with more coordination.
To simplify things, it is easy to imagine that it takes time to learn a movement. For example, the first time a person performs a pushup the movement may be foreign and form may not be optimal. The elbows may flair out and the lower back sag and pushing muscle groups such as the chest, shoulders, and triceps may not be properly activated all resulting in a weak and awkward pushup. With some practice the pushup can be performed properly and for more reps with increased resistance purely through the learning of the movement and no real physiological changes in muscle or connective tissue.
Other factors affecting the body’s response to resistance training involve physiological changes effecting the muscular structure and endocrine system.
The body will actually change physically and hormonally to adapt to the demands that we place upon it. For example, a bodybuilder places the stimulus of high volumes of weight training upon his or her body causing the body to react by increasing the size and strength or muscle fibers in order to be prepared to sustain the occurrence of the stimulus of weight lifting being placed upon it again.
The endocrine system or the system governing our hormones also plays a major role in how our bodies react to stimulus. Many people like to think of hormones as a bad thing like steroids or as something that only pulses through our bodies as teenagers going through puberty. The truth is that hormones are pulsing through our systems at different rates, sending different signals every moment of every day. Yes, both men and women have that crazy steroid testosterone pumping through their bodies every day at any age a differing levels, even without injections. So my point is that hormones signal everything from growth to aging and resistance training can actually help promote a more healthy hormone balance in the body.
The body adapts to everything especially those rows you are doing with that theraband in physical therapy and the adaptations are very beneficial to your health and well being.
Factors include increases in:
Muscle fiber size
Increased contractile proteins
Increased nuclei for protein synthesis
Enzymes such as phosphofructokinase, creatine phosphokinase and myokinase
Resting levels of ATP and PCr as well as glycogen if sufficient carbohydrates are present in the diet
Strength of tendons and ligaments
Muscles may actually grow larger, tendons can thicken and anchor themselves to body better and bone density and strength can increase. All of this is also accompanied by changes in local enzymes increasing energy transfer and efficiency of use. The body can store more ATP and carbohydrates without wasting and use these stores for increased exercise performance.
What all of this means is that through the body’s adaptations to resistance training your muscles can become stronger, tendons and ligaments can become stronger, and your bones can even become stronger all leading to a decreased risk for injury in the future.
Changes also include decreases in:
Body Fat – Many people like to believe that you have to put in countless hours of cardiovascular exercise to lose body fat which can be true, but you can get the results even faster through resistance training or a combination of the two! Resistance training will cause the body to increase muscle size and strength and create a healthier hormone balance as stated above. Both of these adaptations to training will increase the bodies basal metabolic rate or how many calories the body burns just by existing. You will burn more calories just sitting around doing daily activities and will lose weight faster and easier.
Mitochondria volume and density
Training can also induce changes in muscle fiber-type and composition to some degree and usually with quite a bit of training.
Muscle Soreness and Stiffness
Muscle soreness will often be felt two to three days after the performance of a resistance training session. This phenomenon is called delayed onset muscle soreness or DOMS. This feeling is perfectly normal and expected with training.
What are the causes of DOMS?: Not lactic acid buildup! Causes include:
Minute tears in muscle tissue or damage to contractile components accompanying the release of CK, myoglobin, and troponin I
Osmotic shifts that cause fluid retention in surrounding tissue
Overstretching or tearing of portions of connective tissue
Acute inflammation
Alteration in calcium regulation and possibly an altered sarcoplasmic reticulum
If you are feeling muscular soreness (not serious pain), don’t worry about it! It means that you worked hard and your body is repairing itself and getting stronger.
