April 26, 2012 — It’s been debated in clinics, gyms, and research labs for years; which is better — elastic resistance or weight machines?
A 2008 research study showed that Thera-Band elastic resistance is as effective at improving strength as expensive and bulky weight machines (Colado et al. 2008), while a 2010 Denmark study proved that the same exercises using isotonic resistance (weight machine) and elastic resistance have similar levels of muscle activation (Andersen et al. 2010). However until now, no research compared the specific neuromuscular difference between elastic and isotonic resistance.
Researchers in Italy recently published a study that suggests that elastic resistance requires constant neuromuscular adaptation of force compared to isotonic resistance particularly during eccentric contractions.
In other words, elastic resistance may provide more neuromuscular benefit than isotonic resistance. The study was published in the Journal of Electromyography and Kinesiology, the official journal of The International Society of Electrophysiology and Kinesiology (ISEK).
“There has been a long-standing misconception that isotonic resistance is more effective than elastic resistance at improving strength and muscle function in spite of numerous studies that support a comparable or superior effectiveness of bands” stated Phil Page, PT, PhD, ATC, FACSM, director of Thera-Band Academy. “This latest study in particular supports the use of elastic resistance for rehabilitation over isotonic resistance when optimal neuromuscular activation is necessary, particularly early in the healing process.”
The Italian study, lead by Giovanni Melchiorri, MD, PhD, and Alberto Rainoldi, PhD, examined the surface electromyography (EMG) activity of the biceps muscle in 14 healthy males performing a biceps curl with both isotonic weight and Thera-Band elastic tubing. The study compared different manifestations of fatigue between elastic and isotonic resistance. They found that elastic resistance provided higher levels of muscle activity during the eccentric contraction phase due to a more symmetrical strength curve compared to isotonic resistance.
The researchers also found that elastic resistance exercise resulted in faster nerve conduction velocity compared to the isotonic weight machine, yet there was no significant mechanical difference between elastic or isotonic resistance. The researchers concluded that elastic resistance offers more neuromuscular benefit than isotonic weight machines, particularly in specific rehabilitation settings where slow movements with minimal risk of injury are necessary, such as post surgery or for physical activity with elderly people or children.
Page concluded, “This study adds to our body of knowledge on exercise prescription, suggesting that elastic resistance may be more appropriate than isotonic weight machines during the early phases of rehabilitation.”
Source: Performance Health, thera-band.com
Melchiorri G, Rainoldi A. 2011. Muscle fatigue induced by two different resistances: Elastic tubing versus weight machines. Journal of Electrophysiology and Kinesiology, Dec; 21(6):954-9.