Updated: Jan 6, 2019
Why can't we just stretch?
Most evidence supports the sensory theory behind the mechanism for static stretching, that increased joint range of motion (ROM) is due to the bodies ability to tolerate greater stretch without structural changes in the muscle or muscle tendon unit. This means the effects are likely to be short term, furthermore, the decreased force production and performance following static stretching means timing must be considered. Dynamic stretching is beneficial for increasing joint ROM without detrimental effects on force production or performance, however this is short-term and likely due to increased temperature changing viscoelastic properties of the muscle. Self-myofacial release also causes beneficial changes in joint ROM, however these are likely to be of very short duration, thus methods which are longer lasting and have additional benefits may be a useful adjunct.
We know that training with emphasis on the eccentric portion of a muscle action has positive effects on muscle morphology and the nervous system, as well as enhancing the stretch-shortening cycle, improving both muscular strength and power. Eccentric strength training is also likely to aid injury prevention, although most of the research is in team sports, eccentric muscle strength is undoubtedly important for deceleration and stabilisation during jump landings, which are critical in gymnastic performance, especially tumbling.
But what about flexibility and joint ROM?
Unlike stretching and SMR, eccentric training causes increases in muscle length and structural MTU changes producing improvements in joint ROM which are long lasting and more effective than SMR alone. More studies are required examining specific protocols and some resultant temporary muscle soreness may occur, however this can managed, and the long term effect is increased joint ROM.
Either greater load than can be lifted concentrically can be used for only the eccentric portion of the exercises (for eccentric single leg calf raises, two legs can be used for the raise) or, accentuated eccentric muscle action has also been utilised, where both eccentric and concentric action occurs but there is emphasis on the concentric portion. Romanian deadlifts and single leg Swiss ball hamstring curls can be utilised in this way, I get gymnasts to perform these with a 1 second concentric movement followed by a slow controlled 4-5 second eccentric action.
Whilst eccentric training should not replace static and dynamic stretching, or appropriately used SMR, we cannot ignore the potential long term benefits which are unlikely to occur with stretching and SMR, thus we should definitely consider utilising it appropriately for hamstring and calf complexes as part of a periodised s&c plan.