Anaerobic exercise, also called strength training, is a physical exercise intense enough to cause lactate to form. It is used to promote strength, speed and power and by body builders to build muscle mass. Muscle energy systems trained using anaerobic exercise develop differently compared to aerobic exercise, leading to greater performance in short duration, high intensity activities, which last from mere seconds to up to about 2 minutes.
The basic principles of strength training involve a manipulation of the number of repetitions (reps), sets, tempo, exercises and force to cause desired changes in strength, endurance or size by overloading of a group of muscles. The specific combinations of reps, sets, exercises, resistance and force depend on the purpose of the individual performing the exercise: to gain size and strength multiple (4+) sets with fewer reps must be performed using more force. A wide spectrum of regimens can be adopted to achieve different results, but the classic formula recommended by the American College of Sports Medicine reads as follows:
- 8 to 12 repetitions of a resistance training exercise for each major muscle group at an intensity of 40% to 80% of a one-repetition max (RM) depending on the training level of the participant.
- Two to three minutes of rest is recommended between exercise sets to allow for proper recovery.
- Two to four sets are recommended for each muscle group.
Typically failure to use good form during a training set can result in injury or an inability to meet training goals – since the desired muscle group is not challenged sufficiently, the threshold of overload is never reached and the muscle does not gain in strength. There are cases when cheating is beneficial, as is the case where weaker groups become the weak link in the chain and the target muscles are never fully exercised as a result.
When properly performed, strength training can provide significant functional benefits and improvement in overall health and well-being, including increased bone, muscle, tendon, and ligament strength and toughness, improved joint function, reduced potential for injury, increased bone density, increased metabolism, increased fitness and improved cardiac function.
Training commonly uses the technique of progressively increasing the force output of the muscle through incremental weight increases and uses a variety of exercises and types of equipment to target specific muscle groups. Strength training is primarily an anaerobic activity, although some proponents have adapted it to provide the benefits of aerobic exercise through circuit training.
Strength training is typically associated with the production of lactate, which is a limiting factor of exercise performance. Regular endurance exercise leads to adaptations in skeletal muscle which can prevent lactate levels from rising during strength training.
Strength training has a variety of specialized terms used to describe parameters of strength training:
- Exercise – different movements which involve rotating joints in specific patterns to challenge muscles in different ways.
- Form – each exercise has a specific form, a topography of movement designed to maximize safety and muscle strength gains.
- Rep – short for repetition, a rep is a single cycle of lifting and lowering a weight in a controlled manner, moving through the form of the exercise.
- Set – a set consists of several repetitions performed one after another with no break between them with the number of reps per set and sets per exercise depending on the goal of the individual. The number of repetitions one can perform at a certain weight is called the Rep Maximum (RM). For example, if one could perform ten reps at 75 lbs, then their RM for that weight would be 10RM. 1RM is therefore the maximum weight that someone can lift in a given exercise – i.e. a weight that they can only lift once without a break.
- Tempo – the speed with which an exercise is performed; the tempo of a movement has implications for the weight that can be moved and the effects on the muscle.
The benefits of strength training include greater muscular strength, improved muscle tone and appearance, increased endurance and enhanced bone density.
Increased physical attractiveness
Many people take up weight training to improve their physical attractiveness. There is evidence that a body type consisting of broad shoulders and a narrow waist, attainable through strength training, is the most physically attractive male attribute according to women participating in the research. Most men can develop substantial muscles; most women lack the testosterone to do it, but they can develop a firm, "toned" physique, and they can increase their strength by the same proportion as that achieved by men (but usually from a significantly lower starting point). An individual's genetic make-up dictates the response to weight training stimuli to a significant extent, training cannot exceed a muscle's intrinsic genetically determined qualities, but clearly polymorphic expression of Myosin heavy chains is possible.
Workouts elevate metabolism for up to 14 hours following 45-minutes of vigorous exercise.
Increased general physical health
Strength training also provides functional benefits. Stronger muscles improve posture, provide better support for joints, and reduce the risk of injury from everyday activities. Older people who take up weight training can prevent some of the loss of muscle tissue that normally accompanies aging—and even regain some functional strength—and by doing so become less frail. They may be able to avoid some types of physical disability. Weight-bearing exercise also helps to prevent osteoporosis and to improve bone strength in those with osteoporosis. The benefits of weight training for older people have been confirmed by studies of people who began engaging in it even in their 80s and 90s.
Though strength training can stimulate the cardiovascular system, many exercise physiologists, based on their observation of maximal oxygen uptake, argue that aerobics training is a better cardiovascular stimulus. Central catheter monitoring during resistance training reveals increased cardiac output, suggesting that strength training shows potential for cardiovascular exercise.
Strength training may be important to metabolic and cardiovascular health. Recent evidence suggests that resistance training may reduce metabolic and cardiovascular disease risk. Overweight individuals with high strength fitness exhibit metabolic/cardiovascular risk profiles similar to normal-weight, fit individuals rather than overweight unfit individuals.
For rehabilitation or to address an impairment
For many people in rehabilitation or with an acquired disability, such as following stroke or orthopedic surgery, strength training for weak muscles is a key factor to optimize recovery. For people with such a health condition, their strength training is likely to need to be designed by an appropriate health professional, such as a physiotherapist or an occupational therapist.
Increased sports performance
Stronger muscles improve performance in a variety of sports. Sport-specific training routines are used by many competitors. These often specify that the speed of muscle contraction during weight training should be the same as that of the particular sport.
A study was carried out to see what recovery methods best suit sports recovery, in particular basketball players. There were three recovery methods used; stretching and carbohydrates, compression, and cold water immersion. The experiment was carried out over a 3 day basketball tournament to see which method worked best. The best methods proved to be cold water immersion and compression. However several factors could change the results of this study like extending the duration of the study and the effort exerted by the players involved.
For the pleasure of the activity
One side effect of intense exercise is increased levels of dopamine, serotonin, and norepinephrine, which can help to improve mood and counter feelings of depression (It should be noted that dopamine and serotonin were not found to be increased by resistance training).
Developing research has demonstrated that many of the benefits of exercise are mediated through the role of skeletal muscle as an endocrine organ. That is, contracting muscles release multiple substances known as myokines which promote the growth of new tissue, tissue repair, and various anti-inflammatory functions, which in turn reduce the risk of developing various inflammatory diseases.
There are many methods of strength training. Examples include weight training, circuit training, isometric exercise, gymnastics, plyometric, Parkour, yoga, Pilates, Super Slow.
Strength training may be done with minimal or no equipment, for instance bodyweight exercises. Equipment used for strength training includes barbells and dumbbells, weight machines and other exercise machines, weighted clothing, resistance bands, gymnastics apparatus, Swiss balls, wobble boards, Indian clubs, pneumatic exercise equipment, hydraulic exercise equipment.
Exercises for specific muscle groups
Strength trainers commonly divide the body's individual muscles into ten major muscle groups. These do not include the hip, neck and forearm muscles, which are rarely trained in isolation. The most common exercises for these muscle groups are listed below.
The sequence shown below is one possible way to order the exercises. The large muscles of the lower body are normally trained before the smaller muscles of the upper body, because these first exercises require more mental and physical energy. The core muscles of the torso are trained before the shoulder and arm muscles that assist them. Exercises often alternate between "pushing" and "pulling" movements to allow their specific supporting muscles time to recover. The stabilizing muscles in the waist should be trained last.
Realization of training goals
For developing endurance, gradual increases in volume and gradual decreases in intensity is the most effective program. Sets of thirteen to twenty repetitions develop anaerobic endurance, with some increases to muscle size and limited impact on strength.
It has been shown that for beginners, multiple-set training offers minimal benefits over single-set training with respect to either strength gain or muscle mass increase, but for the experienced athlete multiple-set systems are required for optimal progress. However, one study shows that for leg muscles, three sets are more effective than one set.
Beginning weight-trainers are in the process of training the neurological aspects of strength, the ability of the brain to generate a rate of neuronal action potentials that will produce a muscular contraction that is close to the maximum of the muscles potential.
Weights for each exercise should be chosen so that the desired number of repetitions can just be achieved.
In one common method, weight training uses the principle of progressive overload, in which the muscles are overloaded by attempting to lift at least as much weight as they are capable. They respond by growing larger and stronger. This procedure is repeated with progressively heavier weights as the practitioner gains strength and endurance.
However, performing exercises at the absolute limit of one's strength (known as one rep max lifts) is considered too risky for all but the most experienced practitioners. Moreover, most individuals wish to develop a combination of strength, endurance and muscle size. One repetition sets are not well suited to these aims. Practitioners therefore lift lighter (sub-maximal) weights, with more repetitions, to fatigue the muscle and all fibers within that muscle as required by the progressive overload principle.
Commonly, each exercise is continued to the point of momentary muscular failure. Contrary to widespread belief, this is not the point at which the individual thinks they cannot complete any more repetitions, but rather the first repetition that fails due to inadequate muscular strength. Training to failure is a controversial topic with some advocating training to failure on all sets while others believe that this will lead to overtraining, and suggest training to failure only on the last set of an exercise. Some practitioners recommend finishing a set of repetitions just before reaching a personal maximum at a given time. Adrenaline and other hormones may promote additional intensity by stimulating the body to lift additional weight (as well as the neuro-muscular stimulations that happen when in "fight-or-flight" mode, as the body activates more muscle fibers), so getting "psyched up" before a workout can increase the maximum weight lifted.
Weight training can be a very effective form of strength training because exercises can be chosen, and weights precisely adjusted, to safely exhaust each individual muscle group after the specific numbers of sets and repetitions that have been found to be the most effective for the individual. Other strength training exercises lack the flexibility and precision that weights offer.
Split training involves working no more than three muscle groups or body parts per day, instead spreading the training of specific body parts throughout a training cycle of several days. It is commonly used by more advanced practitioners due to the logistics involved in training all muscle groups maximally. Training all the muscles in the body individually through their full range of motion in a single day is generally not considered possible due to caloric and time constraints. Split training involves fully exhausting individual muscle groups during a workout, then allowing several days for the muscle to fully recover. Muscles are worked roughly twice per week and allowed roughly 72 hours to recover. Recovery of certain muscle groups is usually achieved on days while training other groups, i.e. a 7-day week can consist of a practitioner training trapezius, side shoulders and upper shoulders to exhaustion on one day, the following day the arms to exhaustion, the day after that the rear, front shoulders and back, the day after that the chest. In this way all mentioned muscle groups are allowed the necessary recovery.
Intensity, volume, and frequency
Three important variables of strength training are intensity, volume, and frequency. Intensity refers to the amount of work required to achieve the activity and is proportional to the mass of the weights being lifted. Volume refers to the number of muscles worked, exercises, sets, and reps during a single session. Frequency refers to how many training sessions are performed per week.
These variables are important because they are all mutually conflicting, as the muscle only has so much strength and endurance, and takes time to recover due to micro-trauma. Increasing one by any significant amount necessitates the decrease of the other two, e.g. increasing weight means a reduction of reps, and will require more recovery time and therefore fewer workouts per week. Trying to push too much intensity, volume and frequency will result in overtraining, and eventually lead to injury and other health issues such as chronic soreness and general lethargy, illness or even acute trauma such as avulsion fractures. A high-medium-low formula can be used to avoid overtraining, with either intensity, volume, or frequency being high, one of the others being medium, and the other being low.
A common training strategy is to set the volume and frequency the same each week (e.g. training 3 times per week, with 2 sets of 12 reps each workout), and steadily increase the intensity (weight) on a weekly basis. However, to maximize progress to specific goals, individual programs may require different manipulations, such as decreasing the weight, and increase volume or frequency.
Making program alterations on a daily basis (daily undulating periodization) seems to be more efficient in eliciting strength gains than doing so every 4 weeks (linear periodization), but for beginners there are no differences between different periodization models.
There are many complicated definitions for periodization, but the term simply means the division of the overall training program into periods which accomplish different goals.
Periodization is the modulating of volume, intensity, and frequency over time, to both stimulate gains and allow recovery.
In some programs for example; volume is decreased during a training cycle while intensity is increased. In this template, a lifter would begin a training cycle with a higher rep range than he will finish with.
A number of techniques have been developed to make weight training exercises more intense, and thereby potentially increase the rate of progress. Many weight lifters use these techniques to bring themselves past a plateau, a duration where a weightlifter may be unable to do more lifting repetitions, sets, or use higher weight resistance.
Drop sets do not end at the point of momentary muscular failure, but continue with progressively lighter weights.
Pyramid sets are weight training sets in which the progression is from lighter weights with a greater number of repetitions in the first set, to heavier weights with fewer repetitions in subsequent sets.
A reverse pyramid is the opposite in which the heavier weights are used at the beginning and progressively lightened.
Burnouts combine pyramids and drop sets, working up to higher weights with low reps and then back down to lower weights and high reps.
The diminishing set method is where a weight is chosen that can be lifted for 20 reps in one set, and then 70 repetitions are performed in as few sets as possible.
Rest-pause (heavy singles)
Rest-pause are performed at or near 1RM, with ten to twenty seconds of rest between each lift. The lift is repeated six to eight times. It is generally recommended to use this method infrequently.
The Giant set, is a form of training that targets one muscle group (e.g. the triceps) with four separate exercises performed in quick succession, often to failure and sometimes with the reduction of weight halfway through a set once muscle fatigue sets in. This form of intense training 'shocks' the muscles and as such, is usually performed by experienced trainers and should be used infrequently.
Supersets combine two or more exercises with similar motions to maximize the amount of work of an individual muscle or group of muscles. The exercises are performed with no rest period between the exercises. An example would be doing bench press, which predominantly works the pectoralis and triceps muscles, and then moving to an exercise that works just the triceps such as the triceps extension or the pushdown.
Push-pull supersets are similar to regular supersets, but exercises are chosen which work opposing muscle groups. This is especially popular when applied to arm exercises, for example by combining biceps curls with the triceps pushdown. Other examples include the shoulder press and lat pulldown combination, and the bench press and wide grip row combination.
Pre-exhaustion combines an isolation exercise with a compound exercise for the same muscle group. The isolation exercise first exhausts the muscle group, and then the compound exercise uses the muscle group's supporting muscles to push it further than would otherwise be possible. For example, the triceps muscles normally help the pectorals perform their function. But in the "bench press" the weaker triceps often fails first, which limits the impact on the pectorals. By preceding the bench press with the pec fly, the pectorals can be pre-exhausted so that both muscles fail at the same time, and both benefit equally from the exercise.
Breakdowns were developed by Frederick Hatfield and Mike Quinn to work the different types of muscle fibers for maximum stimulation. Three different exercises that work the same muscle group are selected, and used for a superset. The first exercise uses a heavy weight (~85% of 1 rep max) for around five reps, the second a medium weight (~70% of 1 rep max) for around twelve reps, and finally the third exercise is performed with a light weight (~50% of 1 rep max) for twenty to thirty reps, or even lighter (~40% of 1 rep max) for forty or more reps. (Going to failure is discouraged.) The entire superset is performed three times.
Forced reps occur after momentary muscular failure. An assistant provides just enough help to get the weight trainer past the sticking point of the exercise, and allow further repetitions to be completed. Weight trainers often do this when they are spotting their exercise partner. With some exercises forced reps can be done without a training partner. For example, with one-arm biceps curls the other arm can be used to assist the arm that is being trained.
Cheating is a deliberate compromise of form to maximize reps. Cheating has the advantage that it can be done without a training partner, but compromises safety. A typical example of cheat reps occurs during biceps curls when, beginning with the load at the waist, the exerciser swings the barbell or dumbbell forward and up during the concentric phase utilizing momentum to assist their bicep muscles in moving the load to a shortened muscle position. Momentum assistance during the concentric phase allows them to move greater loads during the more difficult concentric phase. The objective can be to position greater loads of resistance to the biceps in preparation of performing the eccentric phase than the more difficult concentric phase would otherwise allow. Replacing a typical function of a training partner with a solo exerciser performing cheat reps facilitates forced reps or negative reps when training alone.
After a normal set of 6–8 reps (to failure), the weight is re-racked and the trainer takes 10–15 deep breaths, and then performs one more repetition. This process can be repeated for two further repetitions. The twenty-rep squat is another, similar approach, in that it follows a 12–15 rep set of squats with individual rest-pause reps, up to a total of 20 reps.
Weight stripping a.k.a. Number Setting
Weight stripping is a technique used after failure with a normal resistance in certain exercises, particularly with easily adjustable machines, whereby the weight trainer or a partner gradually reduces the resistance after a full set is taken to failure. With each reduction in resistance, as many possible reps are completed and the resistance is then reduced again. This is continued until the resistance is approximately half the original resistance.
Negative reps are performed with much heavier weights. Assistants lift the weight, and then the weight trainer attempts to resist its downward progress through an eccentric contraction. Alternatively, an individual can use an exercise machine for negatives by lifting the weight with both of the arms or legs, and then lowering it with only one. Or they can simply lower weights more slowly than they lift them: for example, by taking two seconds to lift each weight and four seconds to lower it.
Partial reps, as the name implies, involves movement through only part of the normal path of an exercise. Partial reps can be performed with heavier weights. Usually, only the easiest part of the repetition is attempted.
Burns involve mixing partial reps into a set of full range reps in order to increase intensity. The partials can be performed at any part of the exercise movement, depending on what works best for the particular exercise. Also, the partials can either be added after the end of a set or in some alternating fashion with the full range reps. For example, after performing a set of biceps curls to failure, an individual would cheat the bar back to the most contracted position, and then perform several partial reps.
Progressive movement training
Progressive movement training attempts to gradually increase the range of motion throughout a training cycle. The lifter will start with a much heavier weight than they could handle in the full range of motion, only moving through the last 3–5" of the movement. Throughout the training cycle, the lifter will gradually increase the range of motion until the joint moves through the full range of the exercise. This is a style that was made popular by Paul Anderson.
Super slow repetitions are performed with lighter weights. The lifting and lowering phases of each repetition take 10 seconds or more.
By strictly controlling the rest periods between reps and sets a trainer can reduce their level of blood oxygenation, which helps to increase the stress on the muscles.
Wrist straps (lifting straps) are sometimes used to assist in gripping very heavy weights. Wrist straps can be used to isolate muscle groups like in "lat pull-downs", where the trainee would primarily use the latissimus dorsi muscles of the back rather than the biceps. They are particularly useful for the deadlift. Some lifters avoid using wrist straps to develop their grip strength, just as some go further by using thick bars. Wrist straps can allow a lifter initially to use more weight than they might be able to handle safely for an entire set, as unlike simply holding a weight, if it is dropped then the lifter must descend with it or be pulled down. Straps place stress on the bones of the wrist which can be potentially harmful if excessive.
Strength training is a safe form of exercise when the movements are controlled, and carefully defined. Or some safety measures can also be taken before the training. However, as with any form of exercise, improper execution and the failure to take appropriate precautions can result in injury. A helmet, boots, gloves, and back belt can aide in injury prevention. Principles of weight training safety apply to strength training.
Bodybuilding is an activity in which the goal is to increase muscle size and definition. Bodybuilding increases the endurance of muscles, as well as strength, though not as much as if it were the primary goal. Bodybuilders compete in bodybuilding competitions, and use specific principles and methods of strength training to maximize muscular size and develop extremely low levels of body fat. In contrast, most strength trainers train to improve their strength and endurance while not giving special attention to reducing body fat below normal. Strength trainers tend to focus on compound exercises to build basic strength, whereas bodybuilders often use isolation exercises to visually separate their muscles, and to improve muscular symmetry. Pre-contest training for bodybuilders is different again, in that they attempt to retain as much muscular tissue as possible while undergoing severe dieting. However, the bodybuilding community has been the source of many strength training principles, techniques, vocabulary, and customs.
It is widely accepted that strength training must be matched by changes in diet in order to be effective. Although aerobic exercise has been proven to have an effect on the dietary intake of macronutrients, strength training has not and an increase in dietary protein is generally believed to be required for building skeletal muscle with popular sources advising weight trainers to consume a high-protein diet which delivers 1.4 to 1.8 g of protein per kg of body weight per day (0.6 to 0.8 g per pound). Protein that is neither needed for cell growth and repair nor consumed for energy is converted into urea mainly through the deamination process and is excreted by the kidneys. It was once thought that a high-protein diet entails risk of kidney damage, but studies have shown that kidney problems only occur in people with previous kidney disease. However failure to properly hydrate can put an increased strain on the kidney's ability to function. An adequate supply of carbohydrates (5–7 g per kg) is also needed as a source of energy and for the body to restore glycogen levels in muscles.
A light, balanced meal prior to the workout (usually one to two hours beforehand) ensures that adequate energy and amino acids are available for the intense bout of exercise. The type of nutrients consumed affects the response of the body, and nutrient timing whereby protein and carbohydrates are consumed prior to and after workout has a beneficial impact on muscle growth. Water is consumed throughout the course of the workout to prevent poor performance due to dehydration. A protein shake is often consumed immediately following the workout, because both protein uptake and protein usage are increased at this time. Glucose (or another simple sugar) is often consumed as well since this quickly replenishes any glycogen lost during the exercise period. To maximize muscle protein anabolism, recovery drink should contain glucose (dextrose), protein (usually whey) hydrolysate containing mainly dipeptides and tripeptides, and leucine. Some weight trainers also take ergogenic aids such as creatine or steroids to aid muscle growth. However, the effectiveness of some products is disputed and others are potentially harmful.
Sex differences in mass gains
Due to the androgenic hormonal differences between males and females, the latter are generally unable to develop large muscles regardless of the training program used. Normally the most that can be achieved is a look similar to that of a fitness model. Muscle is denser than fat, so someone who builds muscle while keeping the same body weight will occupy less volume; if two people weigh the same (and are the same height) but have different lean body mass percentages, the one with more muscle will appear thinner.
In addition, though bodybuilding uses the same principles as strength training, it is with a goal of gaining muscle bulk. Strength trainers with different goals and programs will not gain the same mass as a professional bodybuilder.
Some weight trainers perform light, high-repetition exercises in an attempt to "tone" their muscles without increasing their size.
Muscle tone or firmness is derived from the increase in actin and myosin cross filaments in the sarcomere. When this occurs the same amount of neurological input creates a greater firmness or tone in the resting continuous and passive partial contraction in the muscle.
Exercises of 6–12 reps cause hypertrophy of the sarcoplasm in slow-twitch and high-twitch muscle fibers, contributing to overall increased muscle bulk. This is not to be confused with myofibril hypertrophy which leads to strength gains. Both however can occur to an extent during this rep range. Even though most are of the opinion that higher repetitions are best for producing the desired effect of muscle firmness or tone, it is not. Low volume strength training of 5 repetitions or fewer will increase strength by increasing actin and myosin cross filaments thereby increasing muscle firmness or tone. The low volume of this training will inhibit the hypertrophy effect.
Lowered-calorie diets have no positive effect on muscle hypertrophy for muscle of any fiber type. They may, however, decrease the thickness of subcutaneous fat (fat between muscle and skin), through an overall reduction in body fat, thus making muscle striations more visible.
Exercises like sit-ups, or abdominal crunches, performs less work than whole-body aerobic exercises thereby expending fewer calories during exercise than jogging, for example.
Hypertrophy serves to maintain muscle mass, for an elevated basal metabolic rate, which has the potential to burn more calories in a given period compared to aerobics. This helps to maintain a higher metabolic rate which would otherwise diminish after metabolic adaption to dieting, or upon completion of an aerobic routine.
Weight loss also depends on the type of strength training used. Weight training is generally used for bulking, but the bulking method will more than likely not increase weight because of the diet involved. However, when resistance or circuit training is used, because they are not geared towards bulking, women tend to lose weight more quickly. Lean muscles require calories to maintain themselves at rest, which will help reduce fat through an increase in the basal metabolic rate.