Strength training develops motor neuron pathways that enhance an athlete's brain-body coordination during functional movements. The “neural adaptations” athletes undergo in training refer to the brain’s ability to recruit muscles to contract and produce a particular movement. Practicing an exercise with resistance teaches an athlete's brain to fire the correct muscles to achieve the desired motion. Over time, the athlete’s technique for the exercise becomes ingrained and the movement becomes more automatic. Show
Motor NeuronsMotor neurons are nerve cells that originate in the central nervous system and end at the muscle fibers in the neuromuscular junction. Signals sent from the brain run along the motor neuron to the muscle fiber to produce movements or muscular contractions. Some motor neurons are devoted to autonomic functions, such as signals sent to the diaphragm to contract which allows individuals to breathe. Alternatively, other motor neurons are dedicated to voluntary movements, like strength training. When attempting new exercises, an athlete’s brain must send signals along motor neurons to the correct muscle fibers in order to contract. When athletes lift heavier weights, the frequency of motor neurons firing increases and the number of muscle fibers contracting increases. Ultimately, the growth in motor neurons and muscle fibers builds muscle mass in athletes. Muscle MemoryMuscle memory, also known as neuromuscular facilitation, is the process by which muscles become familiar with certain motor skills. Furthermore, when signals from the brain are sent to the muscle, a pathway becomes established and this process becomes semi-automatic. Once this happens, athletes won’t need to concentrate intensely to create the desired movement. It is likely that the muscle tissue will also develop long-lasting changes (i.e. increases in fiber size and changes in fiber composition). Strength TrainingFunctional strength training helps athletes develop muscle memory so that they can quickly access their movement patterns during a performance. The neuromuscular system goes through a cycle when developing strength: Teach the brain to fire correct muscles to contract with a new movement, add resistance, recruit more muscle fibers to oppose the resistance, build strength and adapt to the resistance, increase the complexity or resistance, and repeat. Complex strength training exercises involving the whole body demand greater muscle recruitment and more closely approximate the demands in each sport. For example, a deep squat will yield a greater gain for an athlete than a biceps curl because the squat requires coordination among the hamstrings, hips, glutes, quads, and core to complete the movement. Additionally, performing strength exercises when the body is fatigued will teach the brain to recruit muscles when it normally does not. This adaptation is useful at the end of a race, game, or event when an athlete's strength normally begins to wane. Sufficient Load, Velocity, and ComplexityIf athletes do not perform an exercise with sufficient resistance, velocity, or complexity, they might develop muscle memory for an improper movement pattern. Because practice solidifies muscle memory, athletes should pay attention to how they execute resistance training. Sufficient Load:Most resistance training will be conducted at 60-80% of 1RM. More qualitatively, athletes should be getting through 6-8 reps of a given exercise where the last couple reps are challenging. As always, technique takes priority over increasing resistance. In order to reduce the risk of injury, it is important that athletes memorize the right technique before they start adding more resistance. Sufficient Velocity:For each exercise, athletes need to move through the movement with sufficient velocity. Strength training with speed builds neural pathways and movement patterns that enhance performance. Athletes may need to decrease resistance to ensure they can move with enough velocity and the correct technique. Sufficient Complexity:Whole body exercises more closely approximate the neuromuscular demand of movements in sports because they require coordination among several muscle groups to achieve the motion. Functional movements like squats, lunges, and pushups demand complexity and teach the brain to fire all the muscles necessary, whereas isolated movements only fire one muscle group at a time. Complex exercises are the most effective way for athletes to develop full body strength. RecapNeural adaptations are happening all the time during strength training. The brain sends signals along motor pathways to tell muscles when, how quickly, and how powerfully to contract to produce movement. Athletes should take advantage of muscle memory, and coaches should develop strength training programs that implement sufficient resistance, velocity, and complexity in order to maximize performance. To learn more about strength training check out this article about cyclic training and progressions and this article about sports periodization. Resistance training (also called strength training or weight training) is the use of resistance to muscular contraction to build strength, anaerobic endurance and size of skeletal muscles. Resistance training is based on the principle that muscles of the body will work to overcome a resistance force when they are required to do so. When you do resistance training repeatedly and consistently, your muscles become stronger. A well-rounded fitness program includes strength training to improve joint function, bone density, muscle, tendon and ligament strength, as well as aerobic exercise to improve your heart and lung fitness, flexibility and balance exercises. Australia’s physical activity and sedentary behaviour recommend that adults do muscle strengthening activities on at least two days each week. Vary your progressive resistance training program every six to eight weeks to maintain improvement. Variables that can impact on your results include:
If you vary your resistance training program through the number of repetitions and sets performed, exercises undertaken and weights used, you will maintain any strength gains you make. Examples of resistance trainingThere are many ways you can strengthen your muscles, whether at home or the gym. Different types of resistance training include:
Health benefits of resistance trainingPhysical and mental health benefits that can be achieved through resistance training include:
Basic principles of resistance trainingResistance training consists of various components. Basic principles include:
Resistance training for beginnersPre-exercise screening is used to identify people with medical conditions that may put them at a higher risk of experiencing a health problem during physical activity. It is a filter or safety net to help decide if the potential benefits of exercise outweigh the risks for you. Print a copy of AUSactive’s adult pre-exercise screening and discuss it with your doctor, allied health or exercise professional. The Australian Physical Activity and Sedentary Behaviour recommend that you undertake strength building activities at least two days a week. These activities should work all the major muscle groups of your body (legs, hips, back, chest, core, shoulders, and arms). Starting resistance trainingIt is important to pay attention to safety and form in order to reduce the risk of injury. An AUSactive registered can help you develop a safe and effective program. To start, a typical beginner’s strength training program involves:
Your aim is to gradually increase to two to three sets for each exercise – comprising eight to 12 reps, every second or third day. Once you can comfortably complete 12 reps of an exercise, you should look at progressing further. Warming up before resistance trainingWarm up your body before starting your strength training exercises. Start with light aerobic exercise (such as walking, cycling or rowing) for around five minutes in addition to a few dynamic stretches. Dynamic stretching involves slow controlled movements through the full range of motion. Advanced resistance trainingTo get the most gain from resistance training, progressively increase the intensity of your training according to your experience and training goals. This may mean increasing the weight, changing the duration of the contraction (the time during which you sustain holding the weight reducing rest time or increasing the volume of training. Once you’ve been doing resistance training regularly for four to six weeks, you can progressively increase the intensity of your training as your muscles adapt. Research suggests that expert supervision and instruction may improve your results as it will ensure you practice proper technique and follow safety principles. If you experience any discomfort or pain, contact a health professional before progressing with your program. Repetitive maximum (RM) and resistance trainingThe best way to develop muscle strength is for the muscle to contract to its maximum potential at any given time – maximal voluntary contraction (MVC). In resistance training, MVC is measured by the term XRM, where RM is the maximum number of repetitions that can be completed with a given resistance or weight. X is the number of times a certain weight can be lifted before the muscle fatigues. It is the RM range that determines what type of improvements the muscles will make. The optimal range for improving muscle strength is 8–12 RM for a beginner and 2–6 RM for the more advanced. For example, the formula 7RM means the person can lift the weight (let’s say 50 kg) seven times before the muscles are too fatigued to continue. Higher weights mean lower RM – for example, the same person could possibly lift a 65 kg weight, but fewer than seven times. Lower weights typically result in a higher RM – for example, the same person could lift a 35 kg weight about 12 times before muscle fatigue sets in. MVC principles can help you gain the most benefit from your workouts. A good rule of thumb is to only increase the weight between two and 10 per cent once you can comfortably do two repetitions above the maximum. Applying MVC to meet advanced resistance training goalsThe principles of strength training involve manipulation of the number of repetitions (reps), sets, tempo, exercises and force to overload a group of muscles and produce the desired change in strength, endurance, size or shape. Specific combinations of reps, sets, exercises, resistance and force will determine the type of muscle development you achieve. General guidelines, using the RM range, include:
Muscle recovery during advanced resistance trainingMuscle needs time to repair and grow after a workout. Not giving your muscles enough time to recover means they will not get bigger or stronger. A good rule of thumb is to rest the muscle group for at least 48 hours. Once you have sufficient experience in resistance training, and with the support of a qualified allied health or exercise professional, you might like to consider a split program. For example, you could work your upper body on Mondays and Fridays, and your lower body on Wednesdays and Sundays. Gaining strength from advanced resistance trainingMost beginners experience a rapid increase in strength, followed by a plateau or levelling-out of strength improvements. After that, gains in muscle strength and size are hard-earned. When you start resistance training, most of your initial increase in strength is due to a phenomenon called neural adaptation. This means that the nerves servicing the muscles change their behaviour. The nerves are thought to fire more frequently (prompting increased muscle contraction) and more motor units are recruited to perform the contraction (a motor unit is the nerve cell and its associated muscle fibres). This means you become stronger, but the muscles remain the same size – you’ve hit the plateau. In time, muscle cells respond to continuous resistance training by increasing in size (hypertrophy), so don’t be discouraged by reaching the plateau – it is actually an encouraging sign that gains in muscle size are soon to follow. Various techniques may help you shorten the plateau period. Varying your workouts can help you push past a plateau. The theory of variation is that you can coax growth and strength from your muscles by surprising them with a range of different stresses. The muscles will respond in size and strength as they are forced to adapt. Be guided by your gym instructor or personal trainer, but suggestions include:
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