Angus Lindsay

Changes in acute biochemical markers of inflammatory and structural stress in rugby union

Abstract Rugby union is a sport governed by the impacts of high force and high frequency. Analysis of physiological markers following a game can provide an understanding of the physiological response of an individual and the time course changes in response to recovery. Urine and saliva were collected from 11 elite amateur rugby players 24 h before, immediately after, and at 17, 25, 38, 62 and 86 h post-game. Myoglobin, salivary immunoglobulin A and cortisol were analysed by ELISA, whereas neopterin and total neopterin were analysed by high-performance liquid chromatography. There was a significant post-game increase of all four markers. The increases were cortisol 4-fold, myoglobin 2.85-fold, neopterin 1.75-fold and total neopterin 2.3-fold when corrected with specific gravity. All significant changes occurred post-game only, with markers returning to and remaining at baseline within 17 h. The intensity of the game caused significant changes in key physiological markers of stress. They provide an understanding of the stress experienced during a single game of rugby and the time course changes associated with player recovery. Neopterin provides a new marker of detecting an acute inflammatory response in physical exercise, while specific gravity should be considered for urine volume correction post-exercise.

Positional demands of professional rugby

Abstract Rugby union is a physically intense intermittent sport coupled with high force collisions. Each position within a team has specific requirements which are typically based on speed, size and skill. The aim of this study was to investigate the contemporary demands of each position and whether they can explain changes in psychophysiological stress. Urine and saliva samples were collected before and after five selected Super 15 rugby games from 37 players. Total neopterin (NP), cortisol and immunoglobulin A were analysed by SCX-high performance liquid chromatography and enzyme linked immunosorbent assay. Global positioning system software provided distance data, while live video analysis provided impact data. All contemporary demands were analysed as events per minute of game time. Forwards were involved in more total impacts, tackles and rucks compared to backs (p < 0.001), while backs were involved in more ball carries and covered more total distance and distance at high speed per minute of game time (p < 0.01). Loose forwards, inside and outside backs covered significantly more distance at high speed (p < 0.01), while there was a negligible difference with number of impacts between the forward positions. There was also minimal difference between positions in the percentage change in NP, cortisol and sIgA. The results indicate distance covered and number of impacts per minute of game time is position-dependent whereas changes in psychophysiological stress are independent. This information can be used to adapt training and recovery interventions to better prepare each position based on the physical requirements of the game.

Measurement of changes in urinary neopterin and total neopterin in body builders using SCX HPLC

Abstract Body building is a sport where ultrastructual damage to muscle fibres aids the development of dense muscle layers. Using a new strong cation exchange (SCX) based chromatography technique to measure neopterin and 7,8-dihydroneopterin, we investigated whether this muscle damage caused increased levels of inflammation. Urine samples were collected over eight consecutive mornings from 10 natural competitive body builders. Samples were analysed using SCX high performance liquid chromatography (HPLC) with urine volume corrected for creatinine and specific gravity (SG). The majority of subjects showed large changes in both neopterin and total neopterin (7,8-dihydroneopterin+neopterin) levels, though the mean data for the group showed no significant change over the week. There was no evidence of the high intensity resistance training causing an accumulation of inflammation as the values for all the body builders returned to close to the starting values after 2 days rest. The SCX analysis had an intra-specific viability of 3.04% and the inter-specific viability was 5.42%. Urine volume correction with SG was found to give the same values as using creatinine. Creatinine and specific gravity are both reliable methods for correcting for urine volume while SCX HPLC provides a new means of measuring urinary neopterin and total neopterin.

Impact-induced muscle damage and urinary pterins in professional rugby: 7,8-dihydroneopterin oxidation by myoglobin

Muscle damage caused through impacts in rugby union is known to increase oxidative stress and inflammation. Pterins have been used clinically as markers of oxidative stress, inflammation, and neurotransmitter synthesis. This study investigates the release of myoglobin from muscle tissue due to force‐related impacts and how it is related to the subsequent oxidation of 7,8‐dihydroneopterin to specific pterins. Effects of iron and myoglobin on 7,8‐dihydroneopterin oxidation were examined in vitro via strong cation‐exchange high‐performance liquid chromatography (SCX‐HPLC) analysis of neopterin, xanthopterin, and 7,8‐dihydroxanthopterin. Urine samples were collected from 25 professional rugby players pre and post four games and analyzed for myoglobin by enzyme‐linked immunosorbent assay, and 7,8‐dihydroneopterin oxidation products by HPLC. Iron and myoglobin oxidized 7,8‐dihydroneopterin to neopterin, xanthopterin, and 7,8‐dihydroxanthopterin at concentrations at or above 10 μM and 50 μg/mL, respectively. All four games showed significant increases in myoglobin, neopterin, total neopterin, biopterin, and total biopterin, which correlated between each variable (P < 0.05). Myoglobin and iron facilitate 7,8‐dihydroneopterin oxidation to neopterin and xanthopterin. In vivo delocalization of myoglobin due to muscle damage may contribute to oxidative stress and inflammation after rugby. Increased concentrations of biopterin and total biopterin may indicate production of nitric oxide and monoamine neurotransmitters in response to the physical stress.

Assessing the effectiveness of selected biomarkers in the acute and cumulative physiological stress response in professional rugby union through non-invasive assessment

Rugby union is a sport involving high force and frequency impacts making the likelihood of injury a significant risk. The aim of this study was to measure and report the individual and group acute and cumulative physiological stress response during 3 professional rugby games through non-invasive sampling. 24 professional rugby players volunteered for the study. Urine and saliva samples were collected pre and post 3 matches. Myoglobin, salivary immunoglobulin A, cortisol, neopterin and total neopterin (neopterin+7,8-dihydroneopterin) were analysed by high performance liquid chromatography or enzyme linked immunosorbent assay. Significant increases in cortisol, myoglobin, neopterin and total neopterin when urine volume was corrected with specific gravity were observed (p<0.05). Significant decreases in salivary immunoglobulin A concentration were observed for games 1 and 2 while secretion rate decreased after games 2 and 3. Significant decreases were seen with the percent of 7,8-dihydroneopterin being converted to neopterin following games 2 and 3. The intensity of 3 professional rugby games was sufficient to elicit significant changes in the physiological markers selected for our study. Furthermore, results suggest the selected markers not only provide a means for analysing the stress encountered during a single game of rugby but also highlight the unique pattern of response for each individual player.

Realising the Potential of Urine and Saliva as Diagnostic Tools in Sport and Exercise Medicine.

Accurate monitoring of homeostatic perturbations following various psychophysiological stressors is essential in sports and exercise medicine. Various biomarkers are routinely used as monitoring tools in both clinical and elite sport settings. Blood collection and muscle biopsies, both invasive in nature, are considered the gold standard for the analysis of these biomarkers in exercise science. Exploring non-invasive methods of collecting and analysing biomarkers that are capable of providing accurate information regarding exercise-induced physiological and psychological stress is of obvious practical importance. This review describes the potential benefits, and the limitations, of using saliva and urine to ascertain biomarkers capable of identifying important stressors that are routinely encountered before, during, or after intense or unaccustomed exercise, competition, over-training, and inappropriate recovery. In particular, we focus on urinary and saliva biomarkers that have previously been used to monitor muscle damage, inflammation, cardiovascular stress, oxidative stress, hydration status, and brain distress. Evidence is provided from a range of empirical studies suggesting that urine and saliva are both capable of identifying various stressors. Although additional research regarding the efficacy of using urine and/or saliva to indicate the severity of exercise-induced psychophysiological stress is required, it is likely that these non-invasive biomarkers will represent “the future” in sports and exercise medicine.

The physiological response to cold-water immersion following a mixed martial arts training session

Combative sport is one of the most physically intense forms of exercise, yet the effect of recovery interventions has been largely unexplored. We investigated the effect of cold-water immersion on structural, inflammatory, and physiological stress biomarkers following a mixed martial arts (MMA) contest preparation training session in comparison with passive recovery. Semiprofessional MMA competitors (n = 15) were randomly assigned to a cold-water immersion (15 min at 10 °C) or passive recovery protocol (ambient air) completed immediately following a contest preparation training session. Markers of muscle damage (urinary myoglobin), inflammation/oxidative stress (urinary neopterin + total neopterin (neopterin + 7,8-dihydroneopterin)), and hypothalamic-pituitary axis (HPA) activation (saliva cortisol) were determined before, immediately after, and 1, 2, and 24 h postsession. Ratings of perceived soreness and fatigue, counter movement jump, and gastrointestinal temperature were also measured. Concentrations of all biomarkers increased significantly (p < 0.05) postsession. Cold water immersion attenuated increases in urinary neopterin (p < 0.05, d = 0.58), total neopterin (p < 0.05, d = 0.89), and saliva cortisol after 2 h (p < 0.05, d = 0.68) and urinary neopterin again at 24 h (p < 0.01, d = 0.57) in comparison with passive recovery. Perceived soreness, fatigue, and gastrointestinal temperatures were also lower for the cold-water immersion group at several time points postsession whilst counter movement jump did not differ. Combative sport athletes who are subjected to impact-induced stress may benefit from immediate cold-water immersion as a simple recovery intervention that reduces delayed onset muscle soreness as well as macrophage and HPA activation whilst not impairing functional performance.

Repetitive cryotherapy attenuates the in vitro and in vivo mononuclear cell activation response

What is the central question of this study? Acute and repetitive cryotherapy are routinely used to accelerate postexercise recovery, although the effect on resident immune cells and repetitive exposure has largely been unexplored and neglected. What is the main finding and its importance? Using blood‐derived mononuclear cells and semi‐professional mixed martial artists, we show that acute and repetitive cryotherapy reduces the in vitro and in vivo T‐cell and monocyte activation response whilst remaining independent of the physical performance of elite athletes.

The physiological and mononuclear cell activation response to cryotherapy following a mixed martial arts contest: A pilot study

Abstract Cold water immersion is thought to reduce the inflammatory response to injury. Using cultured mononuclear cells and human subjects in a mixed martial arts (MMA) contest, we examined the effect of cryotherapy on 7,8-dihydroneopterin and neopterin generation. Urine was collected from 10 elite male mixed martial artists before, immediately post and 1, 2, 24 and 48 h following a contest. Myoglobin was analysed by reverse-phase high performance liquid chromatography, and urinary neopterin and total neopterin (neopterin+7,8-dihydroneopterin) were measured by strong cation exchange high-performance liquid chromatography. Cold water immersion and passive recovery were compared using changes in these markers, while cryotherapy tested total neopterin production in γ-interferon and phorbol myristate acetate (PMA)-stimulated blood-derived mononuclear cells (monocytes/T cells). Myoglobin significantly increased (p<0.05) at 1 h post-contest, neopterin significantly increased at 1 and 24 h (p<0.05), total neopterin significantly increased (p<0.05) at 1 h post for the passive group only, and significant individual variation was observed for all markers (p<0.01). Cold water immersion attenuated total neopterin production (p<0.05), while cryotherapy significantly reduced total neopterin production in PMA-stimulated mononuclear cells (p<0.01). Cryotherapy attenuates the post-exercise inflammatory response following an MMA contest. The evidence also suggests that the mechanisms responsible for this may be related to direct immune cell suppression.

Effect of varied recovery interventions on markers of psychophysiological stress in professional rugby union

Abstract Rugby union is a physical demanding sport that requires optimum recovery between games to maintain performance levels. Analysis of four unique biochemical markers of stress is measured here to determine which recovery strategy currently in use by a professional team provides the necessary requirements for sustained performance. Urine and saliva samples were collected from 37 professional rugby players before, immediately after and 36 hours after five home games, and analysed by enzyme linked immunosorbent assay and high performance liquid chromatography for urinary myoglobin, total neopterin (NP; NP + 7,8-dihydroneopterin), salivary cortisol and immunoglobulin A. Subjects completed a cold water immersion (CWI) or pool session (PS), donned compression garments, consumed protein and carbohydrate food and fluid, and slept for 8 hours post-game. The following day subjects choose from one or a combination of CWI, PS or active recovery/stretching to complete. There was no difference between the recovery protocols for cortisol, total NP, immunoglobulin A concentration or myoglobin at 36 hours post-game. Immunoglobulin A secretion rate significantly increased above pre-game levels at 36 hours post-game for all protocols; however, protocol three did not increase as much (p = 0.038). Total NP was also significantly increased above pre-game levels at 36 hours post-game for all protocols. This study provides evidence that the immediate post-game recovery intervention following a game of professional rugby union may be the most important aspect of psychophysiological player recovery, irrespective of the “next-day” intervention. The concentrations of total NP and immunoglobulin A suggest these professional rugby players are still in a state of recovery 36 hours post-game.