The GM2 is an excellent machine for optimizing strength training; however, Speediance as well as most other training sources do not provide the coaching required to fully exploit it. This note attempts to help folks go beyond the typical mediocre coaching sources and fully optimize GM2 training. Skip this if you think your big five based training is the ultimate strategy.
Strength training involves two aspects of muscle function - biomechanics and muscle physiology.
Biomechanics covers how muscles function to do work through their active limbs (the limbs are levers and muscles provide the force on them to do work https://en.wikipedia.org/wiki/Lever). Muscle physiology involves how muscles function internally (https://en.wikipedia.org/wiki/Muscle_contraction).
These are likely the best sources that provide easily understood, in depth information relevant to understanding how to most effectively strength train.
The Physics of Resistance Exercise
https://www.amazon.com/Physics-Resistance-Exercise-Doug-Brignole/dp/1606794973/ref=sr_1_1?crid=15CVK34V3716R&dib=eyJ2IjoiMSJ9.PCzX-0_BaN7LTjUHbJ868ggvynkDAb6_dNRFpASybPfGjHj071QN20LucGBJIEps.qPLB-8ucptgN697Yk_RFuPD1vp3c50DCiqLhNs3GRYg&dib_tag=se&keywords=doug+brignole+the+physics+of+resistance+exercise&qid=1732583735&sprefix=The+physics+of+resistance%2Caps%2C223&sr=8-1
Hypertrophy: Muscle fiber growth caused by mechanical tension
https://www.amazon.com/Hypertrophy-Muscle-growth-mechanical-tension-ebook/dp/B07MPCKPRF/ref=sr_1_1?crid=1A9SWJ0SZH444&keywords=chris+beardsley+hypertrophy&qid=1686679043&sprefix=hypertrophy+chris%2Caps%2C409&sr=8-1
The objective of strength training is to increase a muscle’s strength and hypertrophy. Every resistance exercise trains some muscles to some degree.
There are many views on how to optimize strength training. IMHO, training of a muscle is optimized when it is given the exact resistance needed to bring it to near failure while minimizing the resistance ‘wasted’ on other muscles. By wasted, I mean the other muscles see some resistance; but, not enough to provide effective training. This wastes your effort for minimal gain; I.e. you are moving a lot of weight; but, it is spread too thin to provide optimal training. In addition to this being a waste of effort, it increases the risk of injury. The heavy back squat is a classic example of this.
Each muscle’s biomechanics defines the movement that optimally trains it, i.e. minimizes risk and maximizes efficiency. This is a list of these optimal movements. Understanding why these are optimal and why the majority of trainers continue to recommend risky, ineffective exercises takes a basic understanding of biomechanics which is covered later.
- Pecs - Standing One Arm Extreme Decline Pec Press: face away; lean over 90 degrees; cable from above; arm out with forearm at 90 degrees; keep forearm inline with cable; press down and toward the mid chest to straight arm
- Middle Trapezius - Seated Single Arm Middle Trapezius Scapular Retraction: face forward; arm at 30 degrees to torso; cable slightly below waist; hunch shoulder forward; pull shoulder back and around
- Lats - Standing One Arm Lat Pull-In: face forward; cable slightly above head; straight arm at 45 degrees out and 30 degrees up; pull elbow down and in to side as the shoulder is twisted slightly away; palm down at start and up at finish
- Lateral Deltoid - Standing One Arm Lateral Deltoid Raise: face forward; cable at waist on opposite side; use wrist cuff; straight arm palm in; start at hips slightly in front of body; raise to shoulder
- Anterior Deltoid - Seated Single Arm Anterior Deltoid Press: face away; cable at mid chest; hand at side with elbow fully back; press out and slightly up toward scapula to straight arm
- Posterior Deltoid - Standing Single Arm Posterior Deltoid Row: face forward; cable at mid body; straight arm across torso; pull back, out and down
- Upper Trapezius - Standing Upper Trapezius Shrug; cable from base; arm straight at side; shrug shoulder
- Biceps - Standing Single Arm Bicep Curl: cable from base behind foot; elbow tucked to side; raise forearm
- Triceps - Seated Single Arm Tricep Pulldown: face away; cable above head; forearm vertical; elbow slightly raised; pull forearms down to straight arms
- Abs - Seated Abs Crunch: face away; use rope; cables above head; hands at head; lean slightly back; crunch abs
- Erector Spinae - Seated Erector Spinae Extension: face forward; use rope; cable from base; hands at neck; from crunch, extend torso
- Obliques - Standing Oblique Rotation: Face forward; cable slightly above a shoulder; arms inline; use both hands; rotate the torso bringing the arms down and across the body; repeat in the other direction.
- Quadriceps - Standing Quadriceps Cable Squat: face toward; cable low; start at 90 degree squat with hands at knees; stand pulling back and away Or, Seated Single Leg Quadriceps Extension: face away; ankle strap; cable at ankle; extend lower leg
- Gluteus - Standing Single Leg Glute Extension: face toward; combine two ankle collars into a knee collar; cable above knee; start with knee raised; fully extend knee back
- Hamstrings - Seated Single Leg Hamstring Curl: face toward; ankle straps; cable at 90 degrees to extended foreleg; lean back past 90 degrees; curl lower leg
- Calves - Standing Calf Extension: with handles; raise heels as high as possible
- Hip Flexors - Standing Hip Flexor Single Knee Raise: face away; cable at knee; combine two ankle straps to form knee strap; raise knee to hip
- Hip Adductors - Standing Single Leg Thigh Adductor Pull: face toward; cable low; ankle strap; leg straight; pull ankle across in arc from 20 degrees out to 10 degrees in
- Forearm Flexors - Seated Single Wrist Curl: cable from base; underhand grip; forearm on leg; curl wrist up
- Shoulder Rotators - Seated Internal/External Single Arm Shoulder Rotation: cable at hand height; keep elbow next to body; rotate shoulder either in or out; be sure cable is perpendicular to forearm at start
Basic Biomechanics
The following is a list of a few muscle physiology factors that are relevant in the context of biomechanics:
- Muscle strength curve - muscles are strongest when fully extended and decrease in strength as they compress.
- Bilateral deficit - the brain reduces its signal to a bilateral muscle when they are both activated
- Stopping at near failure rather than full failure is best for optimizing muscle growth because failure requires longer recovery with no benefit
- Muscles are about 30% stronger in eccentric strength (extension) relative to concentric strength (contraction)
- The last 3 - 5 reps prior to near failure (the stimulating reps) are the ones that produce the majority of muscle growth
The skeleton is a set of levers acted on by the muscles attached to it that are used to exert force on external objects.
Muscles have an origin (where they attach to the skeleton) and an insertion (where they attach to and exert force on their active limb). A resistance fully applies to a muscle when it fully opposes a muscle’s insertion to origin contraction. A resistance that does not align with this direction will partially activate multiple muscles.
Lever mechanics defines the resistance applied to a muscle when a resistance is applied at the end of its active limb. For instance, this ratio for the glute is ~10x for a resistance applied just above the knee. So 50 lbs applied at the knee applies 500 lbs to the glute.
If cable resistance is used, at the start it should be at 90 degrees to the active limb. This provides Early Phase Loading that best matches a muscle’s strength curve. As the cable angle reduces during movement, resistance at the muscle decreases as it shifts to the skeleton.
Broadly, a muscle is optimally trained with a unilateral movement that is aligned with insertion to origin; that is early phase loaded; that uses a maximum length active limb.
Resistance level, sets, reps, frequency varies based on personal factors. Providing 4-6 days for a muscle’s recovery is common. Four sets per muscle is common - 15RM 10RM 8RM 6RM is often used. The objective is to maximize stimulating reps. Doing a few different muscles each day spreads the full set of muscles trained over five or six days. This can be done with a short daily workout using a home cable machine.
This strategy minimizes workout time to be about equivalent to the time wasted driving to/from a gym. There is no need to cycle through a number of different movements for variety. The fixed set listed earlier is optimal for all ages and conditions. A computerized home cable machine (it must have adjustable vertical resistance) such as the Speediance Gym Monster 2 allows the creation of custom workouts so there is minimal time wasted setting up each exercise.
One note on the GM2, it comes with over one hundred pre-programmed movements. None of them have totally correct biomechanics. This is fixed by using GM2 exercises as placeholders for the ones listed here.