Effects of Protein Hydrolysate Supplement on Systemic Muscle Function Markers Following Resistance Type Exercise in Male Subjects

Following muscle injury or exertion, several muscle specific enzymes (CK, LDH), metabolites (Acylcarnitine, FFAs) and inflammatory cytokines (IL-6, CRP) display a temporal increase in expression over 24-96hrs. For example, the muscle specific isoform of CK has been demonstrated to be elevated in the serum of subjects following eccentric resistance training with increased expression from 3hrs post exercise with a peak between 72 hrs and 96 hrs post exercise and up to 120 hrs post exercise.

Similarly, post training muscle homeostasis and injury is also associated with the infiltration of white blood cell populations namely macrophages and neutrophils, this increase in infiltration is accompanied by increases in the expression of inflammatory cytokines such as IL-6 and Il-8.

Specifically, the interleukin IL-6, has been found to be increased in concentration by up to 10-fold, compared to pre-exercise baseline, when subjects complete knee extension, cardio-vascular or eccentric exercise-based routines. Similar post-exercise or injury related increases in markers such as CRP and LDH have also been identified.

While these processes form part of the natural biological processes underpinning muscle and homeostasis, excessive or chronic elevation of these factors can prolong recovery, exacerbate injury and impair performance. Therefore, developing natural interventions that enhance or augment muscle homeostasis, reduce the likelihood of muscle injury and suppress excessive post-exercise inflammatory responses (IL-6, CRP), to enhance recovery would be highly desirable.

Several studies have been conducted where the effect of naturally derived compounds or milk-based products have been explored. Recent analysis of bovine colostrum in lower-division football players demonstrated that 3g supplementation over a 6-week period could significantly reduce the expression of markers such as CK, CRP and IL-6 following Loughborough Intermittent Shuttle Tests.

This reduction in systemic markers induced by the supplementation also corresponded to an improved performance in this routine as compared to subjects receiving 3g of whey supplementation. Resistance type exercise represents an effective model to examine the effects of injury on this panel of markers and is a controlled experimental condition to investigate the efficacy of supplementation on both performance and underlying biochemical processes.

Nutritional strategies to improve post-exercise blood marker profiles are scarce, but there is evidence that the right strategy can be effective both in females and males across a lifespan.

Resistance exercise (1-RM) routines in elderly female subjects have been shown to induce increases in IL-6 and CRP; studies also show that whey supplementation can assist in suppressing post-exercise increases in IL-6. Furthermore, male endurance athletes (aged 18-45 yrs) that supplemented with DHA and EPA showed significant decreases in circulating IL-6 and CK concentrations post-isokinetic testing compared to pre-supplementation.

Therefore, it is important for this study to examine the effects of Nuritas' Elio™ product on post-resistance exercise increases in these key markers of muscle fatigue and injury.

Given the essential role of NAD+ in the regulation of multiple cellular processes known to contribute to age-related decline in cellular function (metabolic homeostasis, DNA damage repair and sirtuin activity), investigators sought to ascertain whether increased pAMPK seen upon in vitro Elio administration translated into an increase in intracellular NAD+ concentration as measured by HPLC.

Preliminary data suggested that treatment of primary human fibroblasts with Elio resulted in a statistically significant increase (p<0.05) in intracellular levels of NAD+ relative to control (mean increase of 17%, ± 6.421 S.E.M., n=4). Given the significant increase in intracellular NAD+ concentration observed in vitro following short-term Elio treatment, longer-term Elio administration in vivo was assessed as a secondary endpoint.

7.2 Introduction

The benefits of regular and routine physical activity and exercise are well documented. Frequent physical activity are necessary tools in preventing modern life-style associated diseases such as type II diabetes, obesity and other cardio-vascular conditions. Nonetheless, injuries resulting from physical activity can have a profound impact on individuals' quality of life and work-place productivity. Periods of intense physical activity and exertion can lead to disruption of normal muscle homeostasis. Resultant muscle injury and recovery can impact upon quality of life especially in adult populations. Socio-economic studies have indicated that common skeletal-muscular injuries commonly encountered by male and female populations during regular exercise account for nearly 49% of work-place absences and 60% of permanent work incapacity. Taking this into account, studies have estimated the cost of these injuries to be in excess of €200bn due to enforced absence and lack of productivity.

It is therefore important to develop products that can lessen the impact of these injuries, which individuals succumb to or expedite their recovery