Does foam rolling actually do any good?

First paragraph: Foam rolling was once for professional athletes only. These days it’s hard to walk into a gym without tripping over somebody rolling around on a neoprene tube. Dedicated classes in hip New York gyms are frequented by the likes of Sarah Jessica Parker and Shakira. Forget protein shakers, resistance bands or Fit Bits: foam rollers are this season’s must-have gym accessory. The rise of foam rollers owes much to the Israeli engineer and physicist Moshe Feldenkrais, whose pioneering work on body movements to improve muscle function became popular in the 1950s. A black belt in judo, Feldenkrais incorporated them into his system for physical improvement when he came across them in the US a couple of decades later.https://theconversation.com/does-foam-rolling-actually-do-any-good-9819

High-threshold motor unit firing reflects force recovery following a bout of damaging eccentric exercise

Exercise-induced muscle damage (EIMD) is associated with impaired muscle function and reduced neuromuscular recruitment. However, motor unit firing behaviour throughout the recovery period is unclear. EIMD impairment of maximal voluntary force (MVC) will, in part, be caused by reduced high-threshold motor unit firing, which will subsequently increase to recover MVC. Fourteen healthy active males completed a bout of eccentric exercise on the knee extensors, with measurements of MVC, rate of torque development and surface electromyography performed pre-exercise and 2, 3, 7 and 14 days post-exercise, on both damaged and control limb. EIMD was associated with decreased MVC (235.2 ± 49.3 Nm vs. 161.3 ± 52.5 Nm; p < 0.001) and rate of torque development (495.7 ± 136.9 Nm.s-1 vs. 163.4 ± 163.7 Nm.s-1; p < 0.001) 48h post-exercise. Mean motor unit firing rate was reduced (16.4 ± 2.2 Hz vs. 12.6 ± 1.7 Hz; p < 0.01) in high-threshold motor units only, 48h post-exercise, and common drive was elevated (0.36 ± 0.027 vs. 0.56 ± 0.032; p < 0.001) 48h post-exercise. The firing rate of high-threshold motor units was reduced in parallel with impaired muscle function, whilst early recruited motor units remained unaltered. Common drive of motor units increased in offset to the firing rate impairment. These alterations correlated with the recovery of force decrement, but not of pain elevation. This study provides fresh insight into the central mechanisms associated with EIMD recovery, relative to muscle function. These findings may in turn lead to development of novel management and preventative procedures

How routine sparring can cause short-term impairment to boxers’ brains

First paragraph: Thrilling the masses for millennia, boxing has evolved down the centuries – rules have changed, equipment improved, training enhanced. However, one key aspect has essentially stayed the same: incapacitating the opponent before they incapacitate youhttps://theconversation.com/how-routine-sparring-can-cause-short-term-impairment-to-boxers-brains-12382

How we discovered that heading a football causes impairment of brain function

First paragraph: Heading a football may look effortless but many scientists have suspected it might actually harm the player&rsquo;s brain. There could be real consequences &ndash; we know that brain injury is linked to an increased risk of dementia, for example. However, it has proven surprisingly difficult to find out the true impact of football heading, partly because mild brain injury is notoriously difficult to detect.&nbsp; Access this article on The Conversation website: https://theconversation.com/how-we-discovered-that-heading-a-football-causes-impairment-of-brain-function-6746

Muscle activation in the loaded free barbell squat: A brief review

The purpose of this article was to review a series of studies (n = 18) where muscle activation in the free barbell back squat was measured and discussed. The loaded barbell squat is widely used and central to many strength training programs. It is a functional and safe exercise that is obviously transferable to many movements in sports and life. Hence, a large and growing body of research has been published on various aspects of the squat. Training studies have measured the impact of barbell squat loading schemes on selected training adaptations including maximal strength and power changes in the squat. Squat exercise training adaptations and their impact on a variety of performance parameters, in particular countermovement jump, acceleration, and running speed, have also been reported. Furthermore, studies have reported on the muscle activation of the lower limb resulting from variations of squat depth, foot placement, training status, and training intensity. There have also been studies on the impact of squatting with or without a weight belt on trunk muscle activation (TMA). More recently, studies have reported on the effect of instability on TMA and squat performance. Research has also shown that muscle activation of the prime movers in the squat exercise increases with an increase in the external load. Also common variations such as stance width, hip rotation, and front squat do not significantly affect muscle activation. However, despite many studies, this information has not been consolidated, resulting in a lack of consensus about how the information can be applied. Therefore, the purpose of this review was to examine studies that reported muscle activation measured by electromyography in the free barbell back squat with the goal of clarifying the understanding of how the exercise can be applied

Athletes, you’re doing weight training all wrong

First paragraph: To become stronger and develop more muscle, you must lift heavier weights over relatively few repetitions. At least, that has been the received wisdom among professional athletes. However, a new body of evidence suggests that it may be wrong. https://theconversation.com/athletes-youre-doing-weight-training-all-wrong-6279

The effectiveness of two novel techniques in establishing the mechanical and contractile responses of biceps femoris

Portable tensiomyography (TMG) and myotonometry (MMT) devices have been developed to measure mechanical and contractile properties of skeletal muscle. The aim of this study was to explore the sensitivity of the aforementioned techniques in detecting a change in passive mechanical properties of the biceps femoris (BF) muscle as a result of change in knee joint angle (i.e. muscle length). BF responses were assessed in 16 young participants (23.4 &plusmn; 4.9 years), at three knee joint angles (0&deg;, 45&deg; and 90&deg;), for maximal isometric torque (MIT) along with myo-electrical activity. Contractile and mechanical properties were measured in a relaxed state. Inter-day reliability of the TMG and MMT was also assessed. MIT changed significantly (p &lt; 0.01) across the three angles, so did stiffness and other parameters measured with MMT (p &lt; 0.01). Conversely, TMG could detect changes only at two knee angles (0&deg; and 45&deg;, p &lt; 0.01), when there is enough tension in the muscle. Reliability was overall insufficient for TMG whilst absolute reliability was excellent (coefficient of variation &lt; 5%) for MMT. The ability of MMT more than TMG to detect an inherent change in stiffness can be conceivably exploited in a number of clinical/therapeutic applications that have to do with unnatural changes in passive muscle stiffness

The Effect of Foam Rolling for Three Consecutive Days on Muscular Efficiency and Range of Motion

Background Foam rolling (FR) has been shown to alleviate some symptoms of exercise-induced muscle damage and has been suggested to increase range of motion (ROM) without negatively impacting strength. However, it is unclear what neuromuscular effects, if any, mediate these changes. Methods In a randomized, crossover design, 16 healthy active males completed 2 min of rest or FR of the knee extensors on three consecutive days. Mechanical properties of vastus lateralis (VL) and rectus femoris (RF) were assessed via Tensiomyography. Knee extension maximal voluntary contraction (MVC) and knee flexion ROM were also assessed, and surface electromyography amplitude (RMS) was recorded during a submaximal isometric contraction (50% of MVC). Measures were performed before and after (0, 15, and 30 min) FR or rest. Results MVC was reduced on subsequent days in the rest condition compared to FR (p = 0.002, pη2 = 0.04); ROM was not different across time or condition (p = 0.193, pη2 = 0.01). Stiffness characteristics of the VL were different on the third day of FR (p = 0.002, pη2 = 0.03). RMS was statistically reduced 0, 15, and 30 min after FR compared to rest (p = 0.006, pη2 = 0.03; p = 0.003, pη2 = 0.04; p = 0.002, pη2 = 0.04). Conclusions Following FR, MVC was elevated compared to rest and RMS was transiently reduced during a submaximal task. Excitation efficiency of the involved muscles may have been enhanced by FR, which protected against the decline in MVC which was observed with rest

The Response To, and Recovery From Maximum Strength and Power Training in Elite Track and Field Athletes

There is a great deal of research on the responses to resistance training; however, information on the responses to strength and power training conducted by elite strength and power athletes is sparse. Purpose:&nbsp;To establish the acute and 24 hour neuromuscular and kinematic responses to Olympic-style barbell strength and power exercise in elite athletes. Methods: Ten elite track and field athletes completed a series of 3 back squat exercises each consisted of 4 x 5 repetitions. These were done as either strength or power sessions on separate days. Surface electromyography (sEMG), bar velocity and knee angle was monitored throughout these exercises and maximal voluntary contraction (MVC), jump height, central activation ratio (CAR) and lactate were measured pre, post and 24 hours thereafter. Results:&nbsp;Repetition duration, impulse and total work were greater (p&lt;0.01) during strength sessions, with mean power being greater (p&lt;0.01) following the power sessions. Lactate increased (p&lt;0.01) following strength but not power sessions. sEMG increased (p&lt;0.01) across sets for both sessions, with the strength session increasing at a faster rate (p&lt;0.01) and with greater activation (p&lt;0.01) by the end of the final set . MVC declined (p&lt;0.01) following the strength and not the power session, which remained suppressed (p&lt;0.05) 24 hours later; whereas CAR and jump height remained unchanged. Conclusion:&nbsp;A greater neuromuscular and metabolic demand following the strength and not power session is evident in elite athletes, which impaired maximal force production up to 24 hours. This is an important consideration for planning concurrent athletic training