Exercise‐induced muscle damage: What is it, what causes it and what are the nutritional solutions?

Abstract

Exercise-induced muscle damage (EIMD) is characterized by symptoms that present both immediately and for up to 14 days after the initial exercise bout. The main consequence of EIMD for the athlete is the loss of skeletal muscle function and soreness. As such, numerous nutrients and functional foods have been examined for their potential to ameliorate the effects of EIMD and accelerate recovery, which is the purpose of many nutritional strategies for the athlete. However, the trade-off between recovery and adaptation is rarely considered. For example, many nutritional interventions described in this review target oxidative stress and inflammation, both thought to contribute to EIMD but are also crucial for the recovery and adaptation process. This calls into question whether long term administration of supplements and functional foods used to target EIMD is indeed best practice. This rapidly growing area of sports nutrition will benefit from careful consideration of the potential hormetic effect of long term use of nutritional aids that ameliorate muscle damage. This review provides a concise overview of what EIMD is, its causes and consequences and critically evaluates potential nutritional strategies to ameliorate EIMD. We present a pragmatic practical summary that can be adopted by practitioners and direct future research, with the purpose of pushing the field to better consider the fine balance between recovery and adaptation and the potential that nutritional interventions have in modulating this balance.

Supplementation with a Mango Leaf Extract (Zynamite®) in Combination with Quercetin Attenuates Muscle Damage and Pain and Accelerates Recovery after Strenuous Damaging Exercise

“…The protocol here applied induced muscle damage as shown by the degree of pain reported, and the increase of circulating biomarkers of muscle damage and inflammation 24 h after the exercise protocol (myoglobin, CRP, CK and ALT). The increase observed here in CK, CRP and myoglobin is similar to that reported after long distance running [2,35]. Consequently, jumping performance was reduced 24 h after the race and drop jumps, which is one of the best indicators of muscle damage and reduction of muscle functional capacity [36].…”

“…Despite the hypothesized role of ROS in EIMD [14,15], the administration of N-acetylcysteine (a thiol-base antioxidant) may be counterproductive, as it has been associated with lower recovery of strength eight days after the exercise [16]. The protective effects of polyphenols after prolonged administration may depend more of the stimulation of the endogenous antioxidant systems through Nrf2 and antioxidant response element pathway signaling [44][45][46], rather than on a direct free radical-scavenging effect [2]. In the case of the combination of Zynamite ® with quercetin, the antioxidant/anti-inflammatory effect due to the inhibition of the ROS-producing enzymes XO and NADP oxidase may explain the effect observed even though only a single dose was administered before exercise.…”

“…soreness, structural disruption, and local inflammation, and it is accompanied by a temporary reduction of muscle force and exercise performance [2]. Although the administration of antioxidants to prevent muscle damage is controversial [3][4][5], some recent studies indicate that ingestion of polyphenol-rich extracts for at least three days before exercise and during the following hours/days may improve recovery [6].…”

“…In the following hours and days after EIMD, the range of motion is reduced, and some swelling appears in the affected limbs [13]. The risk and magnitude of EIMD is exacerbated when muscle contractions are performed at longer muscle length, faster angular velocity, and with higher forces [2]. Although a mechanical disruption of muscle fibers is thought to be the main mechanism starting EIMD, this is followed by a mild inflammatory response, in which reactive oxygen species (ROS) are involved [14,15].…”

The Effect of Orally Dosed Levagen+™ (palmitoylethanolamide) on Exercise Recovery in Healthy Males—A Double-Blind, Randomized, Placebo-Controlled Study

“…PEA also has an essential role in the suppression of inflammation by reducing the activity of pro-inflammatory enzymes cyclooxygenase, endothelial nitric oxide synthase and inducible nitric oxide synthases [11], and mast cell activation [12,13]. These mechanisms of action may also reduce painful symptoms that result from exercise-induced muscle damage and would be advantageous for individuals who require rapid recovery between acute successive bouts of exercise (e.g., sports tournament) [14]. However, to our knowledge no research has undertaken this.…”