Thomas D. Love

The impact of neuromuscular electrical stimulation on recovery after intensive, muscle damaging, maximal speed training in professional team sports players

OBJECTIVES During congested fixture periods in team sports, limited recovery time and increased travel hinder the implementation of many recovery strategies; thus alternative methods are required. We examined the impact of a neuromuscular electrical stimulation device on 24-h recovery from an intensive training session in professional players. DESIGN Twenty-eight professional rugby and football academy players completed this randomised and counter-balanced study, on 2 occasions, separated by 7 days. METHODS After baseline perceived soreness, blood (lactate and creatine kinase) and saliva (testosterone and cortisol) samples were collected, players completed a standardised warm-up and baseline countermovement jumps (jump height). Players then completed 60 m × 50 m maximal sprints, with 5 min recovery between efforts. After completing the sprint session, players wore a neuromuscular electrical stimulation device or remained in normal attire (CON) for 8 h. All measures were repeated immediately, 2 and 24-h post-sprint. RESULTS Player jump height was reduced from baseline at all time points under both conditions; however, at 24-h neuromuscular electrical stimulation was significantly more recovered (mean±SD; neuromuscular electrical stimulation -3.2±3.2 vs. CON -7.2±3.7%; P<0.001). Creatine kinase concentrations increased at all time points under both conditions, but at 24-h was lower under neuromuscular electrical stimulation (P<0.001). At 24-h, perceived soreness was significantly lower under neuromuscular electrical stimulation, when compared to CON (P=0.02). There was no effect of condition on blood lactate, or saliva testosterone and cortisol responses (P>0.05). CONCLUSIONS Neuromuscular electrical stimulation improves recovery from intensive training in professional team sports players. This strategy offers an easily applied recovery strategy which may have particular application during sleep and travel.

Fluid and electrolyte balance during two different preseason training sessions in elite rugby union players.

Abstract Cosgrove, SD, Love, TD, Brown, RC, Baker, DF, Howe, AS, and Black, KE. Fluid and electrolyte balance during two different preseason training sessions in elite rugby union players. J Strength Cond Res 28(2): 520–527, 2014—The purpose of this study was to compare fluid balance between a resistance and an aerobic training sessions, in elite rugby players. It is hypothesized that resistance exercise will result in a higher prevalence of overdrinking, whereas during the aerobic session, underdrinking will be more prevalent. As with previous fluid balance studies, this was an observational study. Twenty-six players completed the resistance training session, and 20 players completed the aerobic training session. All players were members of an elite rugby union squad competing in the southern hemispheres premier competition. For both sessions, players provided a preexercise urine sample to determine hydration status, pre- and postexercise measures of body mass, and blood sodium concentration were taken, and the weight of drink bottles were recorded to calculate sweat rates and fluid intake rates. Sweat patches were positioned on the shoulder of the players, and these remained in place throughout each training session and were later analyzed for sodium concentration. The percentage of sweat loss replaced was higher in the resistance (196 ± 130%) than the aerobic training session (56 ± 17%; p = 0.002). Despite this, no cases of hyponatremia were detected. The results also indicated that more than 80% of players started training in a hypohydrated state. Fluid intake seems to differ depending on the nature of the exercise session. In this group of athletes, players did not match their fluid intakes with their sweat loss, resulting in overdrinking during resistance training and underdrinking in aerobic training. Therefore, hydration strategies and education need to be tailored to the exercise session. Furthermore, given the large number of players arriving at training hypohydrated, improved hydration strategies away from the training venue are required.

The effects of a single whole body cryotherapy exposure on physiological, performance and perceptual responses of professional academy soccer players following repeated sprint exercise

Abstract Russell, M, Birch, J, Love, T, Cook, CJ, Bracken, RM, Taylor, T, Swift, E, Cockburn, E, Finn, C, Cunningham, D, Wilson, L, and Kilduff, LP. The effects of a single whole-body cryotherapy exposure on physiological, performance, and perceptual responses of professional academy soccer players after repeated sprint exercise. J Strength Cond Res 31(2): 415–421, 2017—In professional youth soccer players, the physiological, performance, and perceptual effects of a single whole-body cryotherapy (WBC) session performed shortly after repeated sprint exercise were investigated. In a randomized, counterbalanced, and crossover design, 14 habituated English Premier League academy soccer players performed 15 × 30 m sprints (each followed by a 10 m forced deceleration) on 2 occasions. Within 20 minutes of exercise cessation, players entered a WBC chamber (Cryo: 30 seconds at −60° C, 120 seconds at −135° C) or remained seated (Con) indoors in temperate conditions (∼25° C). Blood and saliva samples, peak power output (countermovement jump), and perceptual indices of recovery and soreness were assessed pre-exercise and immediately, 2-hour and 24-hour postexercise. When compared with Con, a greater testosterone response was observed at 2-hour (+32.5 ± 32.3 pg·ml−1, +21%) and 24-hour (+50.4 ± 48.9 pg·ml−1, +28%) postexercise (both P = 0.002) in Cryo (trial × treatment interaction: P = 0.001). No between-trial differences were observed for other salivary (cortisol and testosterone/cortisol ratio), blood (lactate and creatine kinase), performance (peak power output), or perceptual (recovery or soreness) markers (all trial × treatment interactions: P > 0.05); all of which were influenced by exercise (time effects: all P ⩽ 0.05). A single session of WBC performed within 20 minutes of repeated sprint exercise elevated testosterone concentrations for 24 hours but did not affect any other performance, physiological, or perceptual measurements taken. Although unclear, WBC may be efficacious for professional soccer players during congested fixture periods.

Knowledge and attitudes to vitamin D and sun exposure in elite New Zealand athletes: a cross-sectional study

BackgroundSun safety and vitamin D status are important for prolonged health. They are of particular interest to those working with athletes for whom for whom safe sun practices maybe limited.The aim of this cross-sectional study was to describe the attitudes of elite New Zealand athletes to both vitamin D and sun exposure.Methods110 elite New Zealand outdoor athletes volunteered to participate in an interview with a trained interviewer. The interviewer asked the athletes questions on their Vitamin D knowledge, attitudes and practices regarding sun exposure as well as their concerns about skin cancer.ResultsAthletes were more concerned about their risk of skin cancer (66%) than their vitamin D status (6%). Although the majority (97%) were aware of Vitamin D and could identify the sun as a source (76%) only 17% could name another source of Vitamin D.Only 10 (9%) reported always applying sunscreen before going out in the sun. No athlete reported reapplying sunscreen every hour and 25 suggesting that they never reapply sunscreen.ConclusionsAthletes are concerned about skin cancer however, their use of sunscreen is not optimal suggesting reapplication of sunscreen could be targeted in order to reduce the risk of sun cancer. Awareness of sources of Vitamin D other than the sun may also need to be improved potentially through educational interventions and possibly in conjunction with sun smart messages.

β-hydroxy β-methylbutyrate (hmb) supplementation effects on body mass and performance in elite male rugby union players

Abstract McIntosh, ND, Love, TD, Haszard, J, Osborne, H, and Black, KE. &bgr;-hydroxy &bgr;-methylbutyrate (HMB) supplementation effects on body mass and performance in elite male rugby union players. J Strength Cond Res 32(1): 19–26, 2018—Preseason is characterized by high training volumes with short recovery periods &bgr;-hydroxy &bgr;-methylbutyrate (HMB) has been postulated to assist with recovery. &bgr;-hydroxy &bgr;-methylbutyrate has been shown to improve strength and body composition among untrained groups; the benefits of HMB among trained populations are unclear because of the methodologies employed. This randomized control trail determined the effects of 11 weeks HMB supplementation on body mass and performance measures in 27 elite rugby players. &bgr;-hydroxy &bgr;-methylbutyrate group (n = 13), mean ± SD age 20.3 ± 1.2 years, body mass 99.6 ± 9.1 kg; placebo group (n = 14), age 21.9 ± 2.8 years body mass 99.4 ± 13.9 kg for placebo. During the supplementation period, body mass increased with HMB 0.57 ± 2.60 kg but decreased with placebo 1.39 ± 2.02 kg (p = 0.029). There were no significant differences in any of the 4 strength variables (p > 0.05). However, on the yo-yo intermittent recovery test (YoYo IR-1), the placebo group improved 4.0 ± 2.8 levels but HMB decreased 2.0 ± 3.0 levels (p = 0.003). The results of this study suggest that HMB could be beneficial for gaining or maintaining body mass during periods of increased training load. However, it appears that HMB may be detrimental to intermittent running ability in this group although further research is required before firm conclusions can be made. Only 6 participants on HMB managed to complete both YoYo IR-1 tests because of injury, a larger sample size is required to fully investigate this potentially negative effect. Further, the mechanisms behind this decrement in performance cannot be fully explained and requires further biochemical and psychological investigation.

Measured and perceived indices of fluid balance in professional athletes. The use and impact of hydration assessment strategies

ABSTRACT Background: To determine athletes perceived and measured indices of fluid balance during training and the influence of hydration strategy use on these parameters. Methods: Thirty-three professional rugby union players completed a 120 minute training session in hot conditions (35°C, 40% relative humidity). Pre-training hydration status, sweat loss, fluid intake and changes in body mass (BM) were obtained. The use of hydration assessment techniques and players perceptions of fluid intake and sweat loss were obtained via a questionnaire. Results: The majority of players (78%) used urine colour to determine pre-training hydration status but the use of hydration assessment techniques did not influence pre-training hydration status (1.025 ± 0.005 vs. 1.023 ± 0.013 g.ml−1, P = .811). Players underestimated sweat loss (73 ± 17%) to a greater extent than fluid intake (37 ± 28%) which resulted in players perceiving they were in positive fluid balance (0.5 ± 0.8% BM) rather than the measured negative fluid balance (−1.0 ± 0.7% BM). Forty-eight percent of players used hydration monitoring strategies during exercise but no player used changes in BM to help guide fluid replacement. Conclusion: Players have difficulty perceiving fluid intake and sweat loss during training. However, the use of hydration monitoring techniques did not affect fluid balance before or during training.

UNDERSTANDING ATHLETES' USE OF EXERCISE AND NON-EXERCISE BASED INJURY PREVENTION STRATEGIES

Background The success of exercise-based injury prevention strategies is limited by poor compliance and adherence. However an understanding of the use and barriers to nutrition and psychological injury prevention strategies is not currently known. This information may prove useful in the multidisciplinary environment of elite sport. Objective The objective of this study was to understand the use of exercise, nutrition and psychology injury prevention strategies, identify barriers/facilitators to implementation and preferred methods of knowledge dissemination to athletes. Design An online survey was developed based upon theories of behaviour change and injury surveillance in multi-sport event guidelines. Setting Elite (International/National standard) athletes from a variety of sports. Participants Athletes were randomly recruited from (n=50). Assessment of Risk Factors Athletes completed a questionnaire assessing risk perceptions, prevention beliefs, injury prevention strategy use, injury location/type target, outcome expectancies, barriers/facilitators to injury strategy use and current/preferred channels of information dissemination. Main Outcome Measurements Exercise, nutrition and psychology injury prevention strategy use and barriers/facilitators to strategy use. Results Preliminary findings indicate athletes did not engage with any evidence-based multi-component injury prevention programmes but the majority of athletes reported using at least one exercise-based strategy (97% of athletes) and nutrition-based strategy (97%), but fewer athletes used at least one psychology-based strategy (75%). The most common barriers reported by athletes were a lack of relative advantage for exercise-based strategies and poor how-to-knowledge, principles-knowledge and trialability particularly for nutrition and psychology-based strategies. The most common facilitators were similar across all three injury prevention strategies. These were a performance benefit, injury prevention benefit, relevance, awareness-knowledge, and usefulness. Conclusions No athletes engaged with an evidence-based injury prevention program but many used at least one exercise, nutrition or psychology injury prevention strategy. Athletes reported experiencing few barriers to exercise-based strategies but poor how-to-knowledge, principles knowledge and trialability for non-exercise based strategies.

Sodium supplementation during prolonged exercise: effects on plasma sodium and performance

Introduction The reported incidence of exerciseassociated hyponatraemia (plasma sodium concentration <135 mmol/L) in endurance sport has increased notably in recent decades. Sodium supplements have been suggested to attenuate the decline in plasma sodium concentration and hence, prevent the effects of exercise-associated hyponatraemia on performance. This article reviews intervention studies that have assessed the impact of sodium supplements on plasma sodium concentrations and/ or performance during endurance exercise. Conclusion Despite significant results in some laboratory studies show benefits of sodium supplementation, more recent field studies suggest that sodium supplementation has little impact on plasma sodium concentration during a racing situation and no effect on performance. These discrepancies are likely because of design differences between the studies. However, a well-controlled crossover field trial in a hot environment is still required in order to develop practical recommendations. Introduction Exercise-associated hyponatraemia (EAH), is a blood electrolyte disorder induced during the 24 hours, following exercise1. It is defined as a plasma-sodium concentration (plasma [Na+]) less than the normal reference range; for most laboratories it is found to be 135 mmol/L1. Mild hyponatraemia (plasma [Na+] 130 – 135 mmol/L) is often asymptomic2–5, although mild symptoms can develop6. These include bloating, nausea, lethargy, vomiting and headache1,7–9. Whilst such symptoms are not life-threatening, they likely have some effect on exercise performance. They are also non-specific, and can often be confused with the symptoms of dehydration. As the athlete’s plasma [Na+] decreases below 130 mmol/L, the symptoms correspondingly increase in severity. This occurs as a result of cerebral oedema, producing symptoms, such as confusion, disorientation, seizures, respiratory distress, coma and even possible death1,10–13. The incidence rates of EAH for endurance races has been reported to be up to 30% amongst Ironman triathletes1,13–17, and in marathon runners up to 13%3,18–20. Such endurance events host large participation numbers; the 2010 London marathon, for example, hosted 36,000 runners21. With this in consideration, such incidence rates correspond to a large absolute number of EAH sufferers in the sporting population. Whilst excessive fluid consumption has been a clear causative factor of EAH, there is evidence to suggest that excessive sweat sodium loss may also contribute7,8. It has been speculated that sodium supplementation during endurance exercise could attenuate the reduction in plasma [Na+] in these situations22, therefore reduce the risk of EAH and potentially improve performance. The research stems from both laboratory and field studies, each with their own advantages and disadvantages. In this review, intervention trials with a high and low sodium trial, which measure plasma sodium during an endurance exercise protocol will be discussed. These studies are summarised in Table 1. Laboratory studies One of the first laboratory studies was undertaken in 1991 by Barr, Costill and Fink23. Eight participants completed a crossover intervention of three cycling trials, at 55% VO2max for six hours. Participants consumed fluid to match their sweat rate, with either water and/or a 25 mmol/L (29 mmol/h) NaCl saline solution, or they ingested no fluid during the three trials. Barr et al.23 observed no significant differences in plasma [Na+] between the two ‘fluid’ trials (p = 0.27). These results were similar to those seen in another crossover study by Sanders and colleagues24. Six endurance trained male cyclists participated in three trials, again cycling at 55% VO2max, but for a shorter time for 4 hours as compared to Barr et al. This time the participants ingested 4.6 mmol/L (4 mmol/h), 50 mmol/L (48 mmol/h) and 100 mmol/L (96 mmol/h) of a sodium carbohydrate drink (~0.965 L/h). Similar to the findings from Barr et al.23, plasma [Na+] was maintained regardless of whether participants were supplemented with sodium. However, Sanders et al.24 built on these findings to suggest why plasma [Na+] was maintained. When salt tablets were consumed, the intracellular fluid (ICF) moved into the extracellular fluid (ECF), expanding Ep id em io lo gy o f Sp or ts