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Cold water immersion is most effective for recovery of repeat sprint ability and reducing fatigue post an Australian football game
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Most team sports are characterised by repeated short maximal sprint efforts interspersed with longer periods of active recovery or rest. Although a variety of testing protocols have been devised to simulate these activity patterns under controlled conditions, a common limitation is the lack of 'body contact' to simulate the tackling efforts seen in contact sports. Therefore, the purpose of this study was to assess the reliability of a simulated team game protocol with and without 'contact'. Eleven male, team-sport athletes (mean ± SD; age 22 ± 2 yr; BMI 23.0 ± 1.7 kg·m-2) completed four separate testing trials; two 'non-contact' trials (NCON) and two 'contact' (CON) trials of a simulated game to determine the reliability of a range of team sport performance indicators including repeated 15-m sprint time, vertical jump height, heart rate response and ratings of perceived exertion (RPE). The team game protocol involved four sets of 15-min of intermittent running around a circuit replicating the movement patterns observed in team sports, either with or without simulated contact. Within-subject reliability of each performance measure was determined by expressing the typical error of measurement as the coefficient of variation, as well as determining intra-class correlations. Both CON and NCON produced reliable results for a variety of team sport performance indicators including repeated 15-m sprint time, vertical jump height, heart rate response and RPE. Repeated sprint and jump performance declined over time throughout the simulated game (p < 0.05), while heart rate and RPE increased. There was no difference in these performance measures between CON and NCON protocols. As such, these simulated game protocols provide reliable options for assessing team game performance parameters in response to training or other interventions under controlled conditions.
The authors investigated the efficacy of a single exposure to 14 min of cold-water immersion (COLD) and contrast water therapy (CWT) on posttraining recovery in Australian football (AF).
Fourteen AF players participated in 3 wk of standardized training. After week 1 training, all players completed a passive recovery (PAS). During week 2, COLD or CWT was randomly assigned. Players undertook the opposing intervention in week 3. Repeat-sprint ability (6 × 20 m), countermovement and squat jumps, perceived muscle soreness, and fatigue were measured pretraining and over 48 h posttraining.
Immediately posttraining, groups exhibited similar performance and psychometric declines. At 24 h, repeat-sprint time had deteriorated by 4.1% for PAS and 1.0% for CWT but was fully restored by COLD (0.0%). At 24 and 48 h, both COLD and CWT attenuated changes in mean muscle soreness, with COLD (0.6 ± 0.6 and 0.0 ± 0.4) more effective than CWT (1.9 ± 0.7 and 1.0 ± 0.7) and PAS having minimal effect (5.5 ± 0.6 and 4.0 ± 0.5). Similarly, after 24 and 48 h, COLD and CWT both effectively reduced changes in perceived fatigue, with COLD (0.6 ± 0.6 and 0.0 ± 0.6) being more successful than CWT (0.8 ± 0.6 and 0.7 ± 0.6) and PAS having the smallest effect (2.2 ± 0.8 and 2.4 ± 0.6).
AF training can result in prolonged physical and psychometric deficits persisting for up to 48 h. For restoring physical-performance and psychometric measures, COLD was more effective than CWT, with PAS being the least effective. Based on these results the authors recommend that 14 min of COLD be used after AF training.
An increase in research investigating recovery strategies has occurred alongside the increase in usage of recovery by elite athletes. Because there is inconsistent evidence regarding the benefits of recovery on performance, it is necessary to examine research design to identify possible strategies that enhance performance in different athlete settings. The purpose of this review is to examine available recovery literature specifically related to the time frame between performance assessments to identify considerations for both research design and practical use of recovery techniques.
The aim of this study was to assess the effects of a single session of cold or thermoneutral water immersion after a one-off match on muscular dysfunction and damage in soccer players. Twenty-male soccer players completed one match and were randomly divided into cryotherapy (10 min cold water immersion, 10°C, n = 10) and thermoneutral (10 min thermoneutral water immersion, 35°C, n = 10) groups. Muscle damage (creatine kinase, myoglobin), inflammation (C-reactive protein), neuromuscular function (jump and sprint abilities and maximal isometric quadriceps strength), and delayed-onset muscle soreness were evaluated before, within 30 min of the end, and 24 and 48 h after the match. After the match, the players in both groups showed increased plasma creatine kinase activity (30 min, 24 h, 48 h), myoglobin (30 min) and C-reactive protein (30 min, 24 h) concentrations. Peak jump ability and maximal strength were decreased and delayed-onset muscle soreness increased in both groups. However, differential alterations were observed between thermoneutral water and cold water immersion groups in creatine kinase (30 min, 24 h, 48 h), myoglobin (30 min), C-reactive protein (30 min, 24 h, 48 h), quadriceps strength (24 h), and quadriceps (24 h), calf (24 h) and adductor (30 min) delayed-onset muscle soreness. The results suggest that cold water immersion immediately after a one-off soccer match reduces muscle damage and discomfort, possibly contributing to a faster recovery of neuromuscular function.
Players in team sports must recover in a relatively short period of time to perform at optimal levels. To enhance recovery, cryotherapy is widely used. To date, there are limited scientific data to support the use of cryotherapy for recovery. Players (n = 26) from a premier rugby club volunteered to participate in a random control trial (RCT) using contrast baths, ice baths, and no recovery. Statistical analysis, between group and within group, with repeated measures was conducted along with determination of effect sizes in 2 field tests. Pre and postfield tests including a 300-m test and a phosphate decrement test and subjective reports were conducted during the RCT. No significant difference was identified between base tests and retests in the phosphate decrement test or the 300-m tests. Effect size calculations identified a medium to large effect (d = 0.72) for 300-m tests for contrast baths against control. Trivial effects were identified for ice baths (d = 0.17) in the 300-m test against control. Effect size calculations in the phosphate decrement test showed a trivial effect (d = 0.18) contrast baths and a negative effect (d = -0.62) for ice baths. Treatment-treatment analysis identified a large effect for contrast baths (d = 0.99) in the phosphate decrement test and a medium effect for contrast baths (d = 0.53) in the 300-m test. Effect scores across contrast baths, ice baths, and passive recovery along with subjective reports indicate a trend toward contrast baths benefiting recovery in rugby. The continued use of 5-minute ice baths for recovery should be reconsidered based on this research because trends suggest a detrimental effect.
Global positioning system (GPS) monitoring of movement patterns is widespread in elite football including the Australian Football League (AFL). However documented analysis of this activity is lacking. We quantified the movement patterns of AFL football and differences between nomadic (midfield), forward and defender playing positions, and determined whether the physical demands have increased over a four season period. Selected premiership games were monitored during the 2005 (n=80 game files), 2006 (n=244), 2007 (n=632) and 2008 (n=793) AFL seasons. Players were fitted with a shoulder harness containing a GPS unit. GPS data were downloaded after games and the following measures extracted: total distance (km), time in various speed zones, maximum speed, number of surges, accelerations, longest continuous efforts and a derived exertion index representing playing intensity. In 2008 nomadic players covered per game 3.4% more total distance (km), had 4.8% less playing time (min), a 17% higher exertion index (per min), and 23% more time running >18kmh(-1) than forwards and defenders (all p<0.05). Physical demands were substantially higher in the 2008 season compared with 2005: an 8.4% increase in mean speed, a 14% increase in intensity (exertion index) and a 9.0% decrease in playing time (all p<0.05). Nomadic players in AFL work substantially harder than forwards and defenders in covering more ground and at higher running intensities. Increases in the physical demands of AFL football were evident between 2005 and 2008. The increasing speed of the game has implications for game authorities, players and coaching staff.
In this study, we investigated the effect of water immersion on physical test performance and perception of fatigue/recovery during a 4-day simulated soccer tournament. Twenty high-performance junior male soccer players (age 15.9 +/- 0.6 years) played four matches in 4 days and undertook either cold-water immersion (10 +/- 0.5 degrees C) or thermoneutral water immersion (34 +/- 0.5 degrees C) after each match. Physical performance tests (countermovement jump height, heart rate, and rating of perceived exertion after a standard 5-min run and 12 x 20-m repeated sprint test), intracellular proteins, and inflammatory markers were recorded approximately 90 min before each match and 22 h after the final match. Perceptual measures of recovery (physical, mental, leg soreness, and general fatigue) were recorded 22 h after each match. There were non-significant reductions in countermovement jump height (1.7-7.3%, P = 0.74, eta(2) = 0.34) and repeated sprint ability (1.0-2.1%, P = 0.41, eta(2) = 0.07) over the 4-day tournament with no differences between groups. Post-shuttle run rating of perceived exertion increased over the tournament in both groups (P < 0.001, eta(2) = 0.48), whereas the perceptions of leg soreness (P = 0.004, eta(2) = 0.30) and general fatigue (P = 0.007, eta(2) = 0.12) were lower in the cold-water immersion group than the thermoneutral immersion group over the tournament. Creatine kinase (P = 0.004, eta(2) = 0.26) and lactate dehydrogenase (P < 0.001, eta(2) = 0.40) concentrations increased in both groups but there were no changes over time for any inflammatory markers. These results suggest that immediate post-match cold-water immersion does not affect physical test performance or indices of muscle damage and inflammation but does reduce the perception of general fatigue and leg soreness between matches in tournaments.
In studies on work it is important to assess various subjective symptoms, complaints, and annoyances. To measure such symptoms, psychophysical ratio scales may be used, as along with simpler category rating scales. In this paper some of the basic concepts and methods of psychophysics have been described. In the field of heavy physical work and the perception of effort and exertion, one of the most popular methods is the rating of perceived exertion. This scale has been presented together with a new category ratio scale, commonly referred to as the CR-10 scale. Some situations in which it is important to obtain measurements of perceived exertion have also been described in the paper.
The purpose of this study was to compare the effects of cold, heat, and contrast bath treatments on the amount of edema in first- and second-degree sprained ankles during the postacute phase of rehabilitation. Thirty subjects with postacute sprained ankles were assigned to a cold (n = 10), heat (n = 10), or contrast bath (n = 10) treatment group. A specially constructed tank was used to take pretreatment and posttreatment volumetric measurements of subjects' sprained ankles. Descriptive statistics, a 3 x 3 two-way analysis of variance for repeated measures, and Tukey's Honestly Significant Difference post hoc test revealed that cold therapy produced the least edema in subjects with sprained ankles (p less than .05). All three treatments (cold, heat, and contrast bath) produced an increase in the amount of edema in the postacute sprained ankles of the subjects. Heat and contrast bath therapy produced almost identical increases in the amount of ankle edema on each of the three days of the study. We concluded that cold therapy is the most appropriate of the three treatments if the therapeutic objective is to minimize edema before rehabilitative exercise during the third, fourth, and fifth days postinjury for first- and second-degree ankle sprains.
Cryotherapy is an effective treatment for acute sports injury to soft tissue, although the effect of cryotherapy on exercise-induced muscle damage is unclear. The aim of this study was to assess the effects of cold water immersion on the symptoms of exercise-induced muscle damage following strenuous eccentric exercise. After performing a bout of damage-inducing eccentric exercise (eight sets of five maximal reciprocal contractions at 0.58 rad x s(-1)) of the elbow flexors on an isokinetic dynamometer, 15 females aged 22.0+/-2.0 years (mean +/- s) were allocated to a control group (no treatment, n = 7) or a cryotherapy group (n = 8). Subjects in the cryotherapy group immersed their exercised arm in cold water (15 degrees C) for 15 min immediately after eccentric exercise and then every 12 h for 15 min for a total of seven sessions. Muscle tenderness, plasma creatine kinase activity, relaxed elbow angle, isometric strength and swelling (upper arm circumference) were measured immediately before and for 3 days after eccentric exercise. Analysis of variance revealed significant (P < 0.05) main effects for time for all variables, with increases in muscle tenderness, creatine kinase activity and upper arm circumference, and decreases in isometric strength and relaxed elbow angle. There were significant interactions (P<0.05) of group x time for relaxed elbow angle and creatine kinase activity. Relaxed elbow angle was greater and creatine kinase activity lower for the cryotherapy group than the controls on days 2 and 3 following the eccentric exercise. We conclude that although cold water immersion may reduce muscle stiffness and the amount of post-exercise damage after strenuous eccentric activity, there appears to be no effect on the perception of tenderness and strength loss, which is characteristic after this form of activity.
Delayed onset muscle soreness (DOMS) is a familiar experience for the elite or novice athlete. Symptoms can range from muscle tenderness to severe debilitating pain. The mechanisms, treatment strategies, and impact on athletic performance remain uncertain, despite the high incidence of DOMS. DOMS is most prevalent at the beginning of the sporting season when athletes are returning to training following a period of reduced activity. DOMS is also common when athletes are first introduced to certain types of activities regardless of the time of year. Eccentric activities induce micro-injury at a greater frequency and severity than other types of muscle actions. The intensity and duration of exercise are also important factors in DOMS onset. Up to six hypothesised theories have been proposed for the mechanism of DOMS, namely: lactic acid, muscle spasm, connective tissue damage, muscle damage, inflammation and the enzyme efflux theories. However, an integration of two or more theories is likely to explain muscle soreness. DOMS can affect athletic performance by causing a reduction in joint range of motion, shock attenuation and peak torque. Alterations in muscle sequencing and recruitment patterns may also occur, causing unaccustomed stress to be placed on muscle ligaments and tendons. These compensatory mechanisms may increase the risk of further injury if a premature return to sport is attempted.A number of treatment strategies have been introduced to help alleviate the severity of DOMS and to restore the maximal function of the muscles as rapidly as possible. Nonsteroidal anti-inflammatory drugs have demonstrated dosage-dependent effects that may also be influenced by the time of administration. Similarly, massage has shown varying results that may be attributed to the time of massage application and the type of massage technique used. Cryotherapy, stretching, homeopathy, ultrasound and electrical current modalities have demonstrated no effect on the alleviation of muscle soreness or other DOMS symptoms. Exercise is the most effective means of alleviating pain during DOMS, however the analgesic effect is also temporary. Athletes who must train on a daily basis should be encouraged to reduce the intensity and duration of exercise for 1-2 days following intense DOMS-inducing exercise. Alternatively, exercises targeting less affected body parts should be encouraged in order to allow the most affected muscle groups to recover. Eccentric exercises or novel activities should be introduced progressively over a period of 1 or 2 weeks at the beginning of, or during, the sporting season in order to reduce the level of physical impairment and/or training disruption. There are still many unanswered questions relating to DOMS, and many potential areas for future research.
Hernia surgery has been associated with severe pain within the first 24 h postoperatively. The application of cold or cryotherapy has been in use since at least the time of Hippocrates. The physiological and biological effects from the reduction of temperature in various tissues include local analgesia, inhibited oedema formation and reduced blood circulation. Our hypothesis was that cold therapy, applied by means of ice packs, following inguinal hernia surgery, controlled pain postoperatively. Forty patients scheduled for inguinal hernia repair were enrolled in a double-blind, randomized study. Postoperatively, chipped ice in a plastic bag (cold group), and a plastic bag containing only room temperature water (control) were placed over the incision for 20 min. Postoperative pain data were collected at 2, 6 and 24 h after operation according to the well validated visual analogue scale (VAS). The highest pain levels were recorded 2 h postoperatively for both groups. Pain levels then gradually decreased for both the trial groups during the first 24 h postoperatively. There were significant differences in the VAS scores between the groups at 2, 6 and 24 h. We conclude that local cooling is a safe and effective technique for providing analgesia following inguinal hernia repair.
The aim of this study was to assess the effects of cold-water immersion (cryotherapy) on indices of muscle damage following a bout of prolonged intermittent exercise. Twenty males (mean age 22.3 years, s = 3.3; height 1.80 m, s = 0.05; body mass 83.7 kg, s = 11.9) completed a 90-min intermittent shuttle run previously shown to result in marked muscle damage and soreness. After exercise, participants were randomly assigned to either 10 min cold-water immersion (mean 10 degrees C, s = 0.5) or a non-immersion control group. Ratings of perceived soreness, changes in muscular function and efflux of intracellular proteins were monitored before exercise, during treatment, and at regular intervals up to 7 days post-exercise. Exercise resulted in severe muscle soreness, temporary muscular dysfunction, and elevated serum markers of muscle damage, all peaking within 48 h after exercise. Cryotherapy administered immediately after exercise reduced muscle soreness at 1, 24, and 48 h (P < 0.05). Decrements in isometric maximal voluntary contraction of the knee flexors were reduced after cryotherapy treatment at 24 (mean 12%, s(x) = 4) and 48 h (mean 3%, s(x) = 3) compared with the control group (mean 21%, s(x) = 5 and mean 14%, s(x) = 5 respectively; P < 0.05). Exercise-induced increases in serum myoglobin concentration and creatine kinase activity peaked at 1 and 24 h, respectively (P < 0.05). Cryotherapy had no effect on the creatine kinase response, but reduced myoglobin 1 h after exercise (P < 0.05). The results suggest that cold-water immersion immediately after prolonged intermittent shuttle running reduces some indices of exercise-induced muscle damage.
The present study investigated the effects of three hydrotherapy interventions on next day performance recovery following strenuous training. Twelve cyclists completed four experimental trials differing only in 14-min recovery intervention: cold water immersion (CWI), hot water immersion (HWI), contrast water therapy (CWT), or passive recovery (PAS). Each trial comprised five consecutive exercise days of 105-min duration, including 66 maximal effort sprints. Additionally, subjects performed a total of 9-min sustained effort (time trial - TT). After completing each exercise session, athletes performed one of four recovery interventions (randomly assigned to each trial). Performance (average power), core temperature, heart rate (HR), and rating of perceived exertion (RPE) were recorded throughout each session. Sprint (0.1 - 2.2 %) and TT (0.0 - 1.7 %) performance were enhanced across the five-day trial following CWI and CWT, when compared to HWI and PAS. Additionally, differences in rectal temperature were observed between interventions immediately and 15-min post-recovery; however, no significant differences were observed in HR or RPE regardless of day of trial/intervention. Overall, CWI and CWT appear to improve recovery from high-intensity cycling when compared to HWI and PAS, with athletes better able to maintain performance across a five-day period.
To evaluate the effectiveness of recovery strategies on physical performance during a 3-day tournament style basketball competition, 29 male players (mean age 19.1 years, s= 2.1; height 1.84 m, s= 0.34; body mass 88.5 kg, s= 14.7) were assigned to one of three treatment groups: carbohydrate+stretching (7.7 g kg(-1) day(-1), s= 1.7; 'n = 9), cold water immersion (11 degrees C, 5 x 1; n = 10) or full leg compression garments (18 mmHg, approximately 18 h; n = 10). Effects of the recovery strategies on pre-post tournament performance tests were expressed as the mean change (% +/- standard deviation of the change score). Changes and differences were standardized for accumulated game time, assessed against the smallest worthwhile change for each test, and reported qualitatively. Accumulated fatigue was evident over the tournament with small to moderate impairments in performance tests. Sprint and agility performance decreased by 0.7% (s = 1.3) and 2.0% (s = 1.9) respectively. Vertical jump decreased substantially after the first day for all treatments, and remained suppressed post-tournament. Cold water immersion was substantially better in maintaining 20-m acceleration with only a 0.5% (s = 1.4) reduction in 20-m time after 3 days compared with a 3.2% (s = 1.6) reduction for compression. Cold water immersion (-1.4%, s = 1.7) and compression (-1.5%, s = 1.7) showed similar substantial benefits in maintaining line-drill performance over the tournament, whereas carbohydrate+stretching elicited a 0.4% (s =1.8) reduction. Sit-and-reach flexibility decreased for all groups, although cold water immersion resulted in the smallest reduction in flexibility. Basketball tournament play elicited small to moderate impairments in physical test performance. In conclusion, cold water immersion appears to promote better restoration of physical performance measures than carbohydrate + stretching routines and compression garments.
The purpose of this study was to compare four recovery interventions following simulated team sport, intermittent-sprint exercise on consecutive days. Ten female netball players performed four randomized sessions of a simulated netball exercise circuit on consecutive days. Each condition consisted of two identical sessions (Session 1 and 2), with the recovery intervention implemented at the completion of Session 1. Participants performed all interventions involving: passive recovery, active recovery (ACT), cold water immersion (CWI) and contrast water therapy (C(T)WT). No significant differences (p > 0.05) were evident between conditions for exercise performance (vertical jump, 20-m sprint, 10-m sprint, total circuit time) during Session 2. Effect size data indicated trends for an ameliorated decline in 5 x 20-m sprints and vertical jump for C(T)WT and CWI, respectively. C(T)WT demonstrated a significant reduction (p = 0.04) in lactate post-intervention compared to ACT recovery. Further, ACT recovery resulted in a significantly elevated (p < 0.01) heart rate compared to all other conditions postintervention and demonstrated significantly higher (p < 0.01) rating of perceived exertion postintervention and muscle soreness pre-exercise Session 2. It is likely that while interventions may be applicable to team sport practices, the 24-hour recovery period between exercise bouts was sufficient to allow performance to be maintained, regardless of recovery interventions.
To examine the acute and short-term responses of variables obtained during a single countermovement jump (CMJ1); repeated countermovement jump involving 5 consecutive efforts without a pause (CMJ5); and cortisol, testosterone, and testosterone-to-cortisol ratio (T:C) to an elite Australian Rules Football (ARF) match with a view to determining which variables may be most useful for ongoing monitoring.
Twenty-two elite ARF players participating in a preseason cup match performed a CMJ1 and a CMJ5 and provided saliva samples 48 h before the match (48pre), prematch (Pre), postmatch, 24 h post (24post), 72 h post (72post), 96 h post (96post), and 120 h post (120post). The magnitude of change in variables at each time point compared with Pre and 48pre was analyzed using the effect size (ES) statistic.
A substantial decrement in the pre- to postmatch comparison occurred in the ratio of CMJ1 Flight time:Contraction time (ES -0.65 +/- 0.28). Cortisol (ES 2.34 +/- 1.06) and T:C (ES -0.52 +/- 0.42) displayed large pre- to postmatch changes. The response of countermovement variables at 24post and beyond compared with prematch and 48pre was varied, with only CMJ1 Flight time:Contraction time displaying a substantial decrease (ES -0.32 +/- 0.26) postmatch compared with 48pre. Cortisol displayed a clear pattern of response with substantial elevations up to 24post compared with Pre and 48pre.
CMJ1 Flight time:Contraction time appears to be the most useful variable for monitoring neuromuscular status in elite ARF players due to its substantial change compared with 48pre and prematch. Monitoring cortisol, due to its predictable pattern of response, may provide a useful measure of hormonal status.
Statistical guidelines and expert statements are now available to assist in the analysis and reporting of studies in some biomedical disciplines. We present here a more progressive resource for sample-based studies, meta-analyses, and case studies in sports medicine and exercise science. We offer forthright advice on the following controversial or novel issues: using precision of estimation for inferences about population effects in preference to null-hypothesis testing, which is inadequate for assessing clinical or practical importance; justifying sample size via acceptable precision or confidence for clinical decisions rather than via adequate power for statistical significance; showing SD rather than SEM, to better communicate the magnitude of differences in means and nonuniformity of error; avoiding purely nonparametric analyses, which cannot provide inferences about magnitude and are unnecessary; using regression statistics in validity studies, in preference to the impractical and biased limits of agreement; making greater use of qualitative methods to enrich sample-based quantitative projects; and seeking ethics approval for public access to the depersonalized raw data of a study, to address the need for more scrutiny of research and better meta-analyses. Advice on less contentious issues includes the following: using covariates in linear models to adjust for confounders, to account for individual differences, and to identify potential mechanisms of an effect; using log transformation to deal with nonuniformity of effects and error; identifying and deleting outliers; presenting descriptive, effect, and inferential statistics in appropriate formats; and contending with bias arising from problems with sampling, assignment, blinding, measurement error, and researchers' prejudices. This article should advance the field by stimulating debate, promoting innovative approaches, and serving as a useful checklist for authors, reviewers, and editors.
It is well documented in animal and human research that unaccustomed eccentric muscle action of sufficient intensity and/or duration causes disruption of connective and/or contractile tissue. In humans, this appears to be associated with the sensation of delayed onset muscle soreness (DOMS). During the late 1970's, it was proposed that this sensation of soreness might be associated with the acute inflammatory response. However, subsequent research failed to substantiate this theory. The present article suggests that the results of much of the research concerning DOMS reflect events typically seen in acute inflammation. Similarities between the two events include: the cardinal symptoms of pain, swelling, and loss of function; evidence of cellular infiltrates, especially the macrophage; biochemical markers such as increased lysosomal activity and increased circulating levels of some of the acute phase proteins; and histological changes during the initial 72 h. In the final section of this paper, a theoretical sequence of events is proposed, based on research involving acute inflammation and DOMS.
Simulations are of particular advantage in research studies where large samples are necessary to achieve statistical power and the information must be collected under uniform conditions in order to aid interpretation. In the study reported below, simulation was achieved through the use of medical photography accompanied by case studies of the same patients. All information was collected on the same day. The purpose of the study was to determine the validity of the three pressure ulcer risk assessment scales most commonly used in clinical nursing practice in the UK. Each clinical nurse assessed the same four patients using three risk assessment scales and a visual analogue scale designed to capture their own clinical judgement. External validity was assessed by a panel of tissue viability experts who provided independent ratings. Data were obtained from 236 clinical nurses, yielding 941 risk assessments. Experience with this approach to data collection suggests that it requires careful planning. This should include measures to ensure that the simulated information is valid and that all data collectors have been adequately trained and are able to motivate the nurses participating in the study. Providing consideration is given to these issues, the use of simulation can help to collect data that would be difficult to obtain by more conventional means. It is also important to recognize that clinical decisions are de-contextualized in simulations because they are reduced to verbal and visual summaries. The decision to use simulations should thus be taken only if this is acknowledged.
Exercise-induced muscle injury in humans frequently occurs after unaccustomed exercise, particularly if the exercise involves a large amount of eccentric (muscle lengthening) contractions. Direct measures of exercise-induced muscle damage include cellular and subcellular disturbances, particularly Z-line streaming. Several indirectly assessed markers of muscle damage after exercise include increases in T2 signal intensity via magnetic resonance imaging techniques, prolonged decreases in force production measured during both voluntary and electrically stimulated contractions (particularly at low stimulation frequencies), increases in inflammatory markers both within the injured muscle and in the blood, increased appearance of muscle proteins in the blood, and muscular soreness. Although the exact mechanisms to explain these changes have not been delineated, the initial injury is ascribed to mechanical disruption of the fiber, and subsequent damage is linked to inflammatory processes and to changes in excitation-contraction coupling within the muscle. Performance of one bout of eccentric exercise induces an adaptation such that the muscle is less vulnerable to a subsequent bout of eccentric exercise. Although several theories have been proposed to explain this "repeated bout effect," including altered motor unit recruitment, an increase in sarcomeres in series, a blunted inflammatory response, and a reduction in stress-susceptible fibers, there is no general agreement as to its cause. In addition, there is controversy concerning the presence of sex differences in the response of muscle to damage-inducing exercise. In contrast to the animal literature, which clearly shows that females experience less damage than males, research using human studies suggests that there is either no difference between men and women or that women are more prone to exercise-induced muscle damage than are men.
To investigate the effects of cooling human skeletal muscle after strenuous exercise using 31P MR spectroscopy and MR imaging.
14 male subjects (mean age +/- SD, 23.8 +/- 2.3 yr) were randomly assigned to the normal (N = 7) or the cooling group (N = 7). All subjects performed the ankle plantar flexion exercise (12 repetitions, 5 sets). Localized 31P-spectra were collected from the medial gastrocnemius before and after exercise (immediately, 30, 60 min, 24, 48, 96, and 168 h) to determine the ratio of inorganic phosphate to phosphocreatine (Pi/PCr) and intracellular pH. Transaxial T2-weighted MR images of the medial gastrocnemius were obtained to calculate T2 relaxation time (T2), indicative of intramuscular water level, before and after exercise (24, 48, 96, and 168 h). In addition, the muscle soreness level was assessed at the same time as 31P-spectra measurements. Fifteen-minute cold-water immersion was administered to the cooling group after exercise and initial postexercise measurements.
The control group showed significantly increased T2 from rest at 48 h after exercise (P < 0.05), but the cooling group showed no significant change in T2 throughout this study. Both groups showed a significantly decreased intracellular pH immediately after exercise (P < 0.05). After that, the cooling group showed a significantly greater value than the value at rest or the control group at 60 min after exercise (P < 0.05). For the Pi/PCr, no significant change was observed in both groups throughout this study. The muscle soreness level significantly increased immediately and at 24-48 h after exercise in both groups (P < 0.05).
The findings of this study suggest that cooling causes an increase in intracellular pH and prevents the delayed muscle edema.
his paper serves as a companion to our recent study of the movement patterns and game activities of players (from five different positions) during matches in the 2000 Australian Football League season. Using lapsed-time video analysis, the same individual players (n= 11) as filmed in matches were also monitored during 21 in-season, main training sessions conducted by their clubs in order to assess the degree to which training activities matched game demands. In general, the training sessions did not involve physical pressure; therefore there were very few contested marks and ground balls or tackles, shepherds and spoils, thereby not matching these game demands. Players typically had more possessions (kicks and handballs) at training than in games. They also spent a greater percentage of total time standing and less time walking at training than in games. Fast-running and sprinting efforts at training were almost all for durations of <6 secs, which matched game demands, as did changes of direction when sprinting, which were almost all in a 0-90 degrees arc. However, across all players filmed, high intensity (fast-running and sprinting) movements were not performed as frequently at training (one every 76 secs) as in games (one every 51 secs). Therefore, while some game demands were adequately replicated at training, others were not closely simulated, suggesting that, after careful interpretation of these results, some improvements in training practices could be made.
This study investigated whether or not immediate post-game recovery procedures could enhance the rate of recovery in Australian football players in the first 48 hr after a game. Control, stretch, pool walking and hot/cold recoveries were trialled. Typical next day recovery training (25 min of pool exercise) was also performed after each game. Muscle soreness ratings and measures of flexibility (sit and reach) and power (6-s cycling sprint and vertical jump) were obtained 45 hr pre-game (Thursdays) (baseline), 15 hr post-game (Sundays, prior to "next day" recovery) and 48 hr post-game (Mondays). Performance ratios (Sunday and Monday scores divided respectively by the Thursday score) were used as the primary index of recovery. Muscle soreness was significantly greater (p<0.01) than baseline on both Sunday and Monday in all conditions, but no differences between the three recoveries and control were evident. On Sunday, vertical jump and 6-s work and power scores were only significantly lower than baseline values in control and performance ratios recorded two significant differences (vertical jump: pool walking > control, p<0.01; 6-s power: stretch > control, p<0.01) and moderate to large effect sizes (>0.3). No differences were found between the three experimental recoveries. On Monday no significant differences were recorded in performance between the recoveries and the effect sizes were of lower magnitude. In conclusion, recovery of muscle soreness, flexibility and power at 48 hr post-game was not significantly enhanced by performing an immediate post-game recovery beyond that achieved by performing only next day recovery training.
The influence of regular post-exercise cold application to exercised muscles trained by ergometer cycling (leg muscles) or handgrip exercise using a weight-loaded handgrip ergometer (forearm flexor muscles) was studied in human volunteers. Muscle loads were applied during exercise programs three to four times a week for 4-6 weeks. Besides measuring parameters characterizing muscle performance, femoral and brachial artery diameters were determined ultrasonographically. Training effects were identified by comparing pre- and post-training parameters in matched groups separately for the trained limbs cooled after exercise by cold-water immersion and the corresponding trained limbs kept at room temperature. Significant training effects were three times more frequent in the control than in the cold group, including increases in artery diameters in the control but not in the cold group. It is concluded that training-induced molecular and humoral adjustments, including muscle hyperthermia, are physiological, transient and essential for training effects (myofiber regeneration, muscle hypertrophy and improved blood supply). Cooling generally attenuates these temperature-dependent processes and, in particular, hyperthermia-induced HSP formation. This seems disadvantageous for training, in contrast to the beneficial combination of rest, ice, compression and elevation in the treatment of macroscopic musculo-tendinous damage.
The purpose of this study was to assess the reliability of a repeated-sprint test, specifically designed for field-hockey, as it was based directly on the time-motion analysis of elite level competition. The test consisted of 6 x 30-m over-ground sprints departing on 25s, with an active recovery (approximately 3.1-3.3 ms(-1)) between sprints. Ten highly trained, male, field-hockey players (mean+/-S.D.: age, 23+/-3 years; body mass, 78.1+/-7.1 kg) participated in this study. Following familiarisation, the subjects performed the repeated-sprint test on two occasions, 7 days apart. The reliability of the test variables was assessed by the typical error of measurement (TE). The total sprint time was very reliable (T(1): 26.79+/-0.76 s versus T2: 26.83+/-0.74 s), as the TE was 0.7% (95% CL, 0.5-1.2%). However, the percent sprint decrement was less reliable (T1: 5.6+/-0.9% versus T2: 5.8+/-1.0%), with the TE being 14.9% (95% CL, 10.8-31.3%). In summary, it is suggested that this field-hockey-specific, repeated-sprint test is very reliable when the results are presented as the total sprint time.
The aim of this study was to compare the effectiveness of two recovery techniques on blood lactate and repeated sprint performance. In a randomised cross-over design 20 junior representative rugby players (aged 19+/-1 years) were given either contrast temperature water therapy or active recovery after performing a repeated sprint test. The test was then repeated 1h later to gauge the effects of the two recovery methods on subsequent repetitive sprinting performance. One week later, the two groups were reversed and the testing repeated. The test consisted of ten 40-m sprints with a 30-s turn-around between sprints. Recovery consisted of 6 min slow jogging (6.8 km h(-1)) for the active recovery group or 6 min of contrast temperature water therapy consisting of three 1-min hip-height immersions in cold water (8-10 degrees C) alternated with three 1-min hot water (38 degrees C) showers. Blood lactate concentration and heart rates were measured throughout the testing. Relative to the active recovery group the contrast temperature water therapy group showed a substantial decrease in blood lactate concentration 3 min after the procedure (-2.1 mmol L(-1), 95% confidence limits, +/-1.8 mmol L(-1)), and substantially lower heart rates both during the procedure (-9.1+/-8.7 min(-1)) as well as 1h later during the second set of sprints (-11.7+/-8.6 min(-1)). Effects of recovery group on repeated sprint performance were small to trivial and unclear. Compared to active recovery, contrast temperature water therapy decreases blood lactate concentration and heart rate but has little effect on subsequent repetitive sprinting performance.
This study aimed to compare the efficacy of hot/cold contrast water immersion (CWI), cold-water immersion (COLD) and no recovery treatment (control) as post-exercise recovery methods following exhaustive simulated team sports exercise. Repeated sprint ability, strength, muscle soreness and inflammatory markers were measured across the 48-h post-exercise period. Eleven male team-sport athletes completed three 3-day testing trials, each separated by 2 weeks. On day 1, baseline measures of performance (10 m x 20 m sprints and isometric strength of quadriceps, hamstrings and hip flexors) were recorded. Participants then performed 80 min of simulated team sports exercise followed by a 20-m shuttle run test to exhaustion. Upon completion of the exercise, and 24h later, participants performed one of the post-exercise recovery procedures for 15 min. At 48 h post-exercise, the performance tests were repeated. Blood samples and muscle soreness ratings were taken before and immediately after post-exercise, and at 24h and 48 h post-exercise. In comparison to the control and CWI treatments, COLD resulted in significantly lower (p<0.05) muscle soreness ratings, as well as in reduced decrements to isometric leg extension and flexion strength in the 48-h post-exercise period. COLD also facilitated a more rapid return to baseline repeated sprint performances. The only benefit of CWI over control was a significant reduction in muscle soreness 24h post-exercise. This study demonstrated that COLD following exhaustive simulated team sports exercise offers greater recovery benefits than CWI or control treatments.
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