FAQ: What are feeder workouts?
Feeder workouts are frequent pump training sessions designed to massively accelerated the hypertrophy of a specific body part. The modern originator of the feeder template is Rich Piana who uploaded several videos on the subject.
According to Rich, feeder workouts should be done the day after a hard training session to nourish the hit muscle group with “fresh nutrients” and speed up the recovery process.
Since the purpose of a feeder workout isn’t to tear the muscle tissue but to fill it with blood, the lifter is advised to use very light weights for very high reps.
For arms, Piana recommended doing 3 supersets of 100 reps. Or in simpler terms, the lifter is advised to do 100 reps for biceps, 100 for triceps and then repeat the entire sequence two more times.
The Science Behind Feeder Workouts
Let’s start with two basic ideas that have been circulating in the world of muscle construction for a long time.
1. Heavy Weights Build the Contractile Proteins
Actin and myosin are the two contractile proteins responsible for muscular contraction. Myosin is the thick filament and the engine whereas actin is the thin filament that just goes along for the ride. During a muscle contraction, the myosin filaments pull the actin by binding to it.
Myofibrillar hypertrophy a.k.a. functional hypertrophy represents an increase of contractile proteins (actin and myosin). People call it functional because it directly contributes to strength/force production.
For myofibrillar hypertrophy to manifest, the muscle has to face a serious challenge that cannot come from light loads.
2. High Reps with Light Weights Result in Sarcoplasmic Hypertrophy
The term sarcoplasmic hypertrophy refers to growth of the sarcoplasm – the internal liquid environment of the muscle cell.
It’s been said that light weights (low-intensity loads) lifted for a great number of sets & reps (high volume) amplify the muscle cell fluid by building up the mitochondria (the cellular power plants) and the capillaries (small blood vessels). As a result, the muscle gets bigger thanks to its increased ability to store glycogen (glucose-based energy reserves) but without developing the capacity to generate more tension.
The promoters of functional training relied on the two notions above to paint powerlifters (strength athletes) as functional and bodybuilders (posers) as non-functional fluff-powered men.
Why? As I explained in the last article on 5×5 training, the advocates of strength training played the role of the good cop and seemingly united with the average consumer by criticizing mainstream bodybuilding and endorsing “real man” training such as powerlifting.
The idea of sarcoplasmic hypertrophy was part of the marketing strategy. To increase the feeling of superiority within the average “wiry” brah, bodybuilders’ muscles had to become “all show and no go”.
It worked. To this very day, many people still think that bodybuilders have fake muscles.
What’s the truth?
Myofibrillar and sarcoplasmic hypertrophy are a duo that works together. Even if a man wanted to build his entire body with “fluff” training and enjoy muscles made of “non-functional jell-o”, it would be impossible since the size of the myofibril (contractible fibre) limits the sarcoplasm within the cell.
Therefore, sooner or later, even the “sarcoplasmic lifter” will have to up the weight to maximize sarcoplasmic hypertrophy. That increase will trigger unavoidable myofibrillar hypertrophy.
In other words, sarcoplasmic hypertrophy is dependent on myofibrillar hypertrophy. One cannot develop 20-inch arms made of glycogen and pumped up blood vessels.
Or in even simpler terms – more meat = more veins.
“But bodybuilders are weak. Powerlifters are strong,” screams the dreamer.
Many natty dreamers still believe that they can grow huge muscles by training like “pure” powerlifters who either don’t take steroids at all or inject “a little bit only before the competitions”.
Here’s the truth.
Powerlifters are failed bodybuilders who don’t diet. The powerlifters in the heavyweight divisions are carrying more muscle mass than many bodybuilders on steroids. How do you think that happens? It’s not the squats.
The answer is trivial – they take drugs too, a lot of them. Many powerlifters are just bodybuilders who do the big three (squat, bench, dead) and peak (max out) occasionally. This certainly was the case at the underground powerlifting gym where I trained a long time ago.
The Positive Effects of Feeder Workouts on Hypertrophy
Feeder workouts cannot directly elicit myofibrillar hypertrophy because the weights are too light. Adults cannot build big arms by curling 10lbs forever.
Sure. Roid users can gain muscle mass without training, but even guys on drugs face limits and focus on progression to maximize their gains.
So, what are the positive effects of feeder workouts?
1. Improved Density of the Capillaries
Heavy strength training with low reps and long rest periods does not improve one’s capillary density and efficiency. According to Tesch et. al (1984) and Kadi et al. (1999), Olympic weightlifters and powerlifters who never bother with pump training have lower capillary density than people who don’t even lift.
This happens because low-rep strength training increases the size of the muscle but does little for the skeletal muscle capillarization. As a result, the number of capillaries per fibre decreases.
Bodybuilders do not have this problem as they tend to train with higher reps and often do pump exercises.
Endurance training does not stimulate appreciable or any hypertrophy in some cases, but it has a profound effect on the capillary system. Feeder workouts are also a form of endurance training since they are done for very high reps. (100).
Therefore, one of the benefits of Piana’s feeder protocol is superior capillary density.
What is the role of muscle capillarization? The capillary system delivers oxygen and nutrients to the muscle groups working hard. The greater the capillary density, the greater the exercise capacity of the muscles involved in the movement.
Does this mean more growth?
A study from 1995 performed in London examined the role of metabolites (intermediate or end products of metabolism) in strength training.
Seven people performed isometric contractions three times a week for 14 weeks. The right leg was trained with four sets of 10s contractions lasting 3 seconds. The rest between the sets was 2 minutes.
The left leg was trained with four much longer contractions lasting 30 seconds. The rest between each contraction was 2 minutes.
The cross-sectional area of the leg doing long contractions increased significantly in comparison to the other leg. The longer contraction protocol resulted in bigger metabolite changes too.
One of the study’s conclusions was that greater exposure to metabolites is somehow linked to larger increases in isometric strength and muscle hypertrophy.
The increased vascularization from pump routines such as Piana’s feeders results in a larger quantity of metabolites and growth factors (naturally occurring substances capable of stimulating cellular growth) reaching the muscle under fire. The final outcome is a more anabolic state.
However, if those additional stimulators have nothing to repair (the muscle isn’t damaged), the only side effect is amplified blood supply to the area and greater capillary density.
For that reason, feeders are done after a heavier workout capable of inducing myofibrillar hypertrophy.
2. Improved Mind-Muscle Connection
Feeder/pump workouts can be a useful tool to teach a lifter how to recruit a certain muscle group during an exercise. For instance, an individual who cannot do many pull-ups may have a hard time feeling the lats engage during the exercise because he/she is busy muscling his/hers way up by any means necessary (survival mode). Conversely, high-rep sets of lat pull-downs would pump up the lats of the lifter and improve muscle control.
3. Joint Health
Connective tissues (tendons and ligaments) have very poor blood supply responsible for their slow recuperation. Hence why some experts recommend doing high-rep work to boost the blood circulation of a joint and speed up its recovery.
While this technique is helpful, it should be implemented only with exercises that do not irritate the tendons and ligaments. For example, if a form of skull-crushers hurts your elbows, doing it frequently and for high reps may cause further irritation and discomfort rather than healing.
The Final Answer
Do feeder workouts for arms work?
The principle behind feeder workouts is logical. First, you train the contractile proteins of a muscle; the next day you pump the muscle with blood to improve its recovery and capillary density.
However, one cannot conclude that feeders are magical because the hard workouts before the feeder day are still the growth engine.
In addition, the lifters doing pump sets during their regular sessions are already improving their capillary density even without the feeder workouts.
In short, feeder workouts offer a boost, but they are no replacement for regular resistance training nor can they work on their own unless the goal is increased capillarization.
What is the best way to increase arm size?
If arm size is the goal, it has to be pursued directly by focusing on basic exercises that hit the arms hard.
Here’s an example list – biceps curls, hammer curls, dips, close grip bench presses and overhead triceps extension for the long head of the triceps.
Doing similar exercises and treating them with respect like main lifts (e.g., squats, deadlifts) is the most rational way to stimulate growth of the arm flexors and extensors. Progressive overload is also necessary as it elicits myofibrillar hypertrophy.
As far as frequency is concerned, 2-3 times a week is a middle ground combining great workload and adequate recovery time.
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Tsatsouline, P., 2011. Beyond Bodybuilding. New York: Dragon Door Publications.
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Schott, J., McCully, K. and Rutherford, O., 1995. The role of metabolites in strength training. European Journal of Applied Physiology and Occupational Physiology, 71(4), pp.337-341.
Korthuis, R., 2011. Skeletal Muscle Circulation. San Rafael, Calif.: Morgan & Claypool Life Sciences.