Download Free Weights or Machines

To Free Weights and or To Machines, That is The Question?
Dan Newmire, Ph.D. Candidate, M.S., CSCS
Numerous beginner weight room patrons, veteran members may have
subjectively, and perceived authorities such as personal trainers and our favorite YouTube
sensations have formed an opinion on the optimal utilization of resistance training
equipment referenced from previous social interactions, social media, and television
celebrities. However, the question remains ‘should one use free weights or should one
use machines?’ The answer is a reverberating “YES!”
The wonderful area we refer to as the ‘weight room, gym, dungeon, sanctuary,
POW camp (probably a little too much)’ has numerous options, for numerous goals,
needs, desires, and imagination. Placing a restriction on these resources seems ignorant
at first though it perceptually, certain exercise modalities may best fit person and their
respective goals with much indeed crossover between modalities. In this article, I would
like to review some empirically supported benefits of these differing modalities
concurrent with some perceived benefits that may help reduce the firm opinions against
or for a certain choice of resistance exercise mode.
The primary focus of any individual with or without a personal training is to
ascertain the fitness goals to find best appropriate exercises and training prescription that
will increase performance or achieve visually assessed goals. Goals such as increases in
strength and power increases in muscle mass or hypertrophy, and lastly visually assessed
cosmetic accomplishments such as increased muscle mass and loss of fat mass. Once this
is determined, the understanding it could be goals that are dynamic and multifaceted the
training style should best fit.
The Benefits of Free Weight Resistance Training
Free weight application of resistance training exercise is defined by a freely
moving body, which includes barbells, dumbbells, associated benches and racks,
medicine balls, throwing instruments, and body weight exercises (push ups), etc. This
format allows for the application of resistance and requires force production to move item
while simultaneously challenging the lifter to control, stabilize, and direct the path of
movement (6). Acute studies using strength specific tests measured on the differing types
of instruments or exercises have consistently concluded that free weights produce
superior strength gains compared to machine training. Through confirmation by
measuring one repetition max (1RMs), free weight training transfers to machine
evaluation better than does machine training transferring to free weight evaluation (6).
Shaner et al. (2014) from our nearby college and laboratory in Denton, TX The
University of North Texas investigated the acute hormonal responses to free weight vs
machine resistance multi-joint exercise. Comparing the barbell back squat (free weight)
and leg press (machine weight) utilizing 6 sets of 10 repetitions of the squat or leg press
with an initial load of 80 % of 1-RM and 2 min of rest between sets. Their primary
finding of that there was a difference between acute hormonal and metabolic (based on
heart rate and lactate) responses to the 2 exercise modes. Overall, the squat exercise
induced greater testosterone, growth hormone (GH), and cortisol hormone and metabolic
responses than the leg press. Testosterone and GH are anabolic hormones and with these
acute transient rises may help explain cell signaling and possible hypertrophy in response
to training. In contrast, cortisol is a catabolic hormone, which can inhibit the cell
signaling processes of hypertrophy; though also is a response to total work meaning
higher levels of cortisol are seemingly related to the amount of work applied; meaning
more overall work was done during back squat than the leg press (4).
Similarly, Schwanbeck et al. (2009) investigated the differences of
electromyographic (EMG) activity of the legs, more specifically the tibialis anterior,
gastrocnemius, vastus medialis, vastus lateralis, biceps femoris and trunk stabilizers
lumbar erector spinae and rectus abdominus during free weight and Smith machine squat
exercises to observed which exercise was optimal for activating musculature. Each
participant was randomized and performed 8-RM of Smith machine squat and free weight
barbell back squat with the while EMG activity of 7 muscles were investigated. Their
working sets that were assessed by way of choosing a weight that the participants thought
they could do for 8 repetitions and was adjusted to maintain an 8-RM. They found that
the free weight barbell back squat prompted a 34 % higher EMG activity from the
gastrocnemius, a 26 % higher from the biceps femoris, and a 49 % higher EMG MAV
from the vastus medialis compared to the Smith machine squat. Furthermore, the overall
average of all muscle groups the free weight barbell back squat exercise induced a 43 %
higher EMG activity when compared to the Smith machine squat. Again, free weight
exercise is supported to be greater than machines by greater muscle activation (3).
Lastly, Spennewyn (2008) compared free-form resistance training with fixed
form resistance training devices to assess if one mode of resistance training machine
would be optimal to the other, relative strength and balance improvements. The fixed
range of motion (in which the participant was unable to deviate from the intended range)
was the leg extension machine and the free range of motion instrument that allows
multiple planes of motion within the specfic exercise movement of the machine.
However, free weights would qualify as a free-form exercise, the gym equipment the
author used as an example was a Freemotion® chest machine due to its inherent exercise
capacity of chest pressing movements, fly movements concurrent with these movements
in their respective low horizontal, horizontal, and high horizontal planes. Additionally,
both the free-form and fixed-from resistance training groups performed one set of 8–12
repetitions to muscle failure two times per week utilizing such equipment relative to their
training groups such as the squat machine, the quadriceps extension, hamstring curl, calf
raise, lat pull down, row machine, chest press, shoulder press, bicep curl, tricep
extension, and standing abdominal machine.
It was observed that strength assessed in beginning and ending total resistance
improved in both groups. However, the free-form group elicited a strength improvement
of 115 % compared to the fixed group with an improvement of 57 %. Their data suggests
that free-form training improved their strength 58 % greater than the fixed form group, is
a more effective mode of improving persons overall strength when compared to the fixed
form. In respect to the standing balance test, the fixed form group improved 49 %
compared to the free form of a 245 % increase in pre and post balance test. Both
resistance exercise groups support past research that strength training is able to improve
balance and reduce the risk of falls; though free-form shows to a more optimal effect.
The author concludes in this statement why free-form resistance exercises may be more
beneficial: “Movement is not the result of isolated actions of individually working
muscles but the complex interrelationship of many muscles and joints stabilizing and
contracting concurrently and sequentially. This ‘‘synergy’’ is further complicated by
the difference between ‘‘machine’’ movements and ‘‘life’’ movements. Movements in
life are neither fixed nor isolated” (5).
!
The Benefits of Machine-based Resistance Training
With reading the previous section on why free weights are overwhelmingly more
optimal than a machine, it becomes confusing how to defend machine use when
resistance training in a gym. However, it is a fairly easy to understand how they are
beneficial. A pronounced argument why machines are beneficial is only comparing them
to free weights in the ‘lens’ of performance. Not every person’s goal or performance is
dictated by strength or maximal performance in an athletic event. For example in the
realm of training for cosmetic enhancement the mode of resistance becomes less
important to the factor and action of resistance training.
Past research observed the iconic company Nautilus® which used variable
resistance mechanism to alter resistance during the range of motion of the chosen muscle
group throughout the range of motion (2), in an effort to match the various exercise
strength curves. Strength curves estimate the torque (force generation by the muscle on a
bone about a joint angle) production capabilities for specified exercise movements.
Strength is defined as the maximal force and torque (rotational force) a musculoskeletal
lever system can generate at a specific velocity. Muscular force generation and torque
production is multifaceted and dependent upon a number of physiological,
biomechanical, and neural drive factors, including muscle cross-sectional area, muscle
length, pennation angle, the radius of the internal and external moment arms, contraction
speed, and the size, number, and type of motor units recruited that thereby mediate the
muscle fiber type (1).
!
What does that all mean in English?
Essentially, not all people in this world i.e. aging adults, special needs, diseased
populations, physique competitors train for athletic events where strength translates to
performance on the proverbial field. Machines may hold value in that they place
resistance on the muscle, will induce strength and hypertrophic responses. They do elicit
muscle activation, and lastly they may anecdotally optimize particular muscle groups
during a training session “lagging body part” while minimizing the influence of
secondary or tertiary muscle groups assisting in the movement.
Lastly, one of the largest and greatest factors that support machine training is
safety! The use of safety as a benefit is apparently very cliché and repetitive though this
is not directly stating free weights are dangerous and machines are “fool proof.” It
merely is a perception that many machines are promoted and maintained so that they are
safe and numerous populations with a range of experience are able to configure its usage
and complete a training session void of injury.
In conclusion, hoping this article is additive to the knowledge of resistance
training in relation to free weights vs. machine optimal "battle," the answer is that they
both are beneficial, and both should be used in a training regiment to optimize training
outcomes. Free weight training exercise may be more beneficial for athletes or persons
that are looking for optimal strength, power for dynamic activities. However, persons
who do not have this personal objective may find this goal and relevant performance
achievement with machine and or free weight training.
!
References
1.
McMaster DT, Cronin J, McGuigan M. Forms of variable resistance training.
Strength & Conditioning Journal. 2009;31(1):50-64.
2.
Pipes TV. Variable resistance versus constant resistance strength training in adult
males. Eur. J. Appl. Physiol. Occup. Physiol. 1978;39(1):27-35.
3.
Schwanbeck S, Chilibeck PD, Binsted G. A comparison of free weight squat to
Smith machine squat using electromyography. The Journal of Strength &
Conditioning Research. 2009;23(9):2588-91.
4.
Shaner AA, Vingren JL, Hatfield DL, Budnar Jr RG, Duplanty AA, Hill DW. The
acute hormonal response to free weight and machine weight resistance exercise.
The Journal of Strength & Conditioning Research. 2014;28(4):1032-40.
5.
Spennewyn KC. Strength outcomes in fixed versus free-form resistance
equipment. The Journal of Strength & Conditioning Research. 2008;22(1):75-81.
6.
Stone MH, Collins D, Plisk S, Haff G, Stone ME. Training Principles: Evaluation
of Modes and Methods of Resistance Training. Strength & Conditioning Journal.
2000;22(3):65.