Accommodating resistance exercise machines
For example, a barbell squat or bench press can be performed with just free weights, with free weights plus elastic bands, with free weights plus chains, with just chains on an empty barbell, or with just bands on an empty barbell.If you have the right set-up, you can even use specially-designed pneumatic machines to provide resistance to the barbell, using cables.
This specificity likely arises largely because the different external load types involve different (1) points where in the exercise range of motion the load is highest, and (2) velocities for a given relative load.By Chris Beardsley, S&C Research columnist Conventional weight training, which can be done with either free weights or machines, is the most well-researched training method for improving athletic ability.In conventional weight training, the external load remains .This produces joint angle range of motion-specific and and velocity-specific adaptations, as well as greater improvements at the endurance end of the strength-endurance continuum.describes how the externally-applied force changes throughout the range of motion of the exercise.By comparing this profile with other types of external load, we can see that free weight loading has 3 key characteristics: externally-applied force over the whole exercise range of motion.
For example, a constant pneumatic resistance machine displays a constant externally-applied force over the whole exercise range of motion.
When working against pneumatic resistance, the barbell accelerates faster, because the loading at the start of the concentric phase is low.
This leads to greater peak bar speeds and power outputs (Frost et al. constant externally-applied force over the whole exercise range of motion.
These include: Some of these types of resistance change depending on where you measure them in the whole exercise range of motion, while others do not.
For example, the weight due to gravity of a barbell does not change depending on where it is in the exercise range of motion.
Accommodating resistance also tends to overcompensate for inertia towards the end, because it is often used to increase force in the middle of the lift as well. Some studies have often reported no external load type specificity of strength gains, although these are primarily limited to those reporting on programs of single-joint knee extension exercises (Manning et al. 2010) or programs of combined single-joint and multi-joint leg extension exercises (Walker et al. Where these studies assessed joint angle-specific changes in strength, they found no effects (Manning et al. These studies have reported on programs of single-joint knee extension exercise (Smith & Melton, 1981; Kovaleski et al. This suggests that the specificity of external load type is probably quite weak.