The most popular reasons for why people focus on strength training for their workouts is to improve their aesthetic appearance and create a ‘toned’ physique. Anyone who has ever spent any time in a weight room has probably relished the opportunity to ‘flex’ and show off his or her freshly sculpted muscles. What good is spending hours in the gym if you can’t show off the results of the hard work? The perception is that large muscles are strong muscles, and showing off an increase in muscle size is one way of saying: ‘Look how strong I am.’
As a long-time fitness professional I believe that anyone who spends the time training, watching their nutrition and following a healthy lifestyle deserves the opportunity to show off the fruits of his or her efforts. However, that said there are two things wrong with the above scenario.
1: muscles do not flex. Muscles either shorten or lengthen, only joints flex (and extend). if someone asks you to ‘flex’ a muscle you can shorten a muscle to create flexion at the joint it crosses but the muscle itself will not flex.
2: big muscles are not necessarily strong muscles. That’s right, just because a muscle has increased in size does not necessarily mean it has experienced a significant increase in strength.
The common misperception is that the larger the muscle, the greater it’s ability to produce a force (i.e. strength). There is a big difference (pun intended) between a muscle’s size and it’s ability to generate force. Muscles can appear large based on the volume of intracellular fluid, blood and water contained in the tissue, this is commonly referred to as the ‘pump’ that occurs after lifting weights and explains why some incredibly strong weightlifters have a completely different physique than bodybuilders. It also explains why some bodybuilders with large muscles and amazing physiques are not necessarily strong weightlifters able to compete effectively in strength-based competitions like Powerlifting or Strongman.
Bodybuilders train for the specific goal of improving size and appearance, this requires isolation training to focus on increasing a muscle’s size, not it’s force output. Weightlifters train to maximize the net magnitude of muscle force they can produce which is a specific skill requiring numerous muscles to work synergistically to contract at the same time. If you are interested in improving strength but don’t necessarily want to experience muscle growth then here are 8 things you should know about strength training.
1.Muscle size is due to sarcoplasmic hypertrophy. Performing a high volume of reps to momentary fatigue produces the response of sarcoplasmic hypertrophy, an increase in size in the fluid-containing sarcoplasm around muscle cells, but not in the individual muscle fibers themselves. Lifting to momentary fatigue fills a muscle with blood that carries oxygen to the muscle to fuel the contractions, it also depletes the muscle of glycogen which is used to create the ATP to fuel the contractions. Post exercise extra blood remains in the muscle to remove metabolic waste, deliver protein to repair damaged tissue and replenish the glycogen used to fuel the contractions. One gram of glycogen can hold up to three grams of water in the muscle cell, as muscle glycogen is restored it holds additional water in the cell which can lead to an acute increase in muscle size. This is how a muscle can get larger without necessary becoming stronger, it is simply storing more fluid which increases the total volume of the muscle cells.
2.Myofibrillar hypertrophy is the foundation of improving strength and is an increase in thickness of the individual myofibrils (muscle fibers) that comprise a unit of muscle. When myofibrils become thicker there is more surface area connecting individual myofibrils to one another. Strength is based on a muscle’s ability to generate tension, as the surface tension between individual fibers increases the net result is greater force output from the entire muscle. As a muscle experiences myofibrillar hypertrophy it becomes thicker and denser, not necessarily larger, this is why many weightlifters lack the over-inflated appearance of their bodybuilding cousins, they are simply using their muscle differently.
3. Increasing strength requires proper stimulation of the nervous system components responsible for causing muscle contractions, in the case of improving strength the goal is to recruit as many fast twitch (type II) muscle motor units as possible within a specific muscle, this is known as ‘intra-muscular coordination.’ A muscle motor unit is the motor neuron, which initiates the signal for a muscle fiber to contract, and the specific fibers to which it is attached. Increasing the number of fast twitch motor units that are activated or ‘switched on’ during an exercise can have a significant impact on the total force a muscle can produce. If you have ever lifted a heavy weight and felt your muscles shaking this is because more type II motor units are being ‘switched on’ (as the type I, slow twitch units fatigue) to shorten their attached fibers and generate the tension necessary to move the applied weight.
4. The Maximal Effort method of training is one way to stimulate a significant amount of fast twitch muscle motor units which results in strength gains. This method requires a near maximal load that can be performed for one-to-three repetitions. The Maximal Effort method does not need to be performed to failure, instead the focus is on moving the weight as fast as possible in order to maximize the number of muscle motor units recruited. Even though a lifter is pushing as fast as possible the exercise itself may not be that quick due to the magnitude of the weight. Using the Maximal Effort method requires long rest intervals of three-to-five minutes to allow both neural and metabolic recovery.
5.The Dynamic Effort method of training focuses on the speed of movement to recruit more type II muscle motor units. Explosively moving a weight requires rapid force production, the nervous system responds by triggering the type II motor units which can produce a high amount of force in a short period of time. The Dynamic Effort method can use elastic bands and chains to create a variable load allowing the lifter to accelerate as fast as possible all of the way through the movement.
6. The Repeated Effort method of weight lifting uses a moderate amount of weight performed until momentary muscle fatigue. Muscle motor units are recruited based on the size principle: when a muscle receives the signal to contract it will recruit smaller type I units first, as the need for force increases the larger, type II units will be called into action. Performing a lift to fatigue at approximately six-to-eight repetitions is one way to recruit all of the involved fibers within that muscle.
7.Using ‘Ladder Sets’ is a training method that can produce significant strength results. This technique, like most successful strength-building methods, was developed by Soviet sport scientists and requires a lifter to allow rest within a specific set to focus on maximal muscle motor unit recruitment without experiencing fatigue. A 1-2-3-4 ladder set requires the lifter to perform one repetition then rest before completing two reps, then allow another rest before completing three repetitions and finally one more brief rest interval before completing four repetitions in a row; that is one set, certain Soviet era strength programs had athletes doing multiple ladder sets to increase training volume. The amount of rest between reps in an individual set is based on the amount of weight and the speed of movement. The goal of a ladder set is to complete all reps with good form in order to optimize lifting technique and movement skill.
8. Rest. This is a requisite component of success for high-performing strength athletes. The training session is when the muscles work, but it’s the post-training period when muscles rest, refuel, repair themselves and generally recover to prepare for the next training session. On those days when you want to focus on developing max strength make sure you allow time for adequate sleep that night for optimal tissue repair and recovery.
Training to momentary muscle fatigue is a successful method for increasing muscle size, but if the goal is to improve muscle strength the training program must focus on achieving successful lifts to recruit and engage as many muscle motor units as possible which does not always require achieving momentary fatigue. As with any method in exercise what may work for some people may not necessarily work for all people, identifying what will help you achieve you or your clients specific strength goals will require some trial and error. For those concerned that lifting weights will add unwanted size simply increasing myofibrillar hypertrophy and motor unit synchronization within a muscle will not necessarily cause a muscle to swell up. In addition adding strength requires the appropriate nutrition to support protein resythesis and glycogen replenishment (the recover and repair process) but that is outside the scope of this post, the purpose of which was to discuss the actual mechanisms of achieving strength gains in the weight room.