***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Abstract A key element of the physical preparation of athletes is the taper period in the weeks immediately preceding competition . Existing research has defined the taper , identified various forms used in contemporary sport , and examined the prescription of training volume , load , intensity , duration , and type ( progressive or step ) . Current limitations include : the lack of studies on team , combative , racquet , and precision ( target ) sports ; the relatively small number of r and omized controlled trials ; the narrow focus on a single competition ( single peak ) compared with multiple peaking for weekly , multi-day or multiple events ; and limited underst and ing of the physiological , neuromuscular , and biomechanical basis of the taper . Future research should address these limitations , together with the influence of prior training on optimal tapering strategies , and the interactions between the taper and long-haul travel , heat , and altitude . Practitioners seek information on how to prescribe tapers from season to season during an athlete 's career , or a team 's progression through a domestic league season , or multi-year Olympic or World Cup cycle . Practical guidelines for planning effective tapers for the Vancouver 2010 and London 2012 Olympics will evolve from both experimental investigations and modelling of successful tapers currently employed in a wide range of sports OBJECTIVES To investigate the physical dem and s of professional rugby league match-play using microtechnology , and to compare these dem and s with typical training activities used to prepare players for competition . DESIGN Prospect i ve cohort study . METHODS Thirty elite rugby league players participated in this study . Seven hundred and eighty-six . training data sets and 104 data sets from National Rugby League matches were collected over one playing season . Movement was recorded using a commercially available microtechnology unit ( minimaxX , Catapult Innovations ) , which provided information on speeds , distances , accelerations , physical collisions and repeated high-intensity efforts . RESULTS Mean distances covered during match-play by the hit-up forwards , wide-running forwards , adjustables , and outside backs were 3,569 m , 5,561 m , 6,411 m , and 6,819 m , respectively . Hit-up forwards and wide-running forwards were engaged in a greater number of moderate and heavy collisions than the adjustables and outside backs , and more repeated high-intensity effort bouts per minute of play ( 1 bout every 4.8 - 6.3 min ) . The physical dem and s of traditional conditioning , repeated high-intensity effort exercise , and skill training activities were all lower than the physical dem and s of competition . CONCLUSIONS These results demonstrate that absolute distances covered during professional rugby league matches are greater for outside backs , while the collision and repeated high-intensity effort dem and s are higher for hit-up forwards and wide-running forwards . The specific physical dem and s of competitive play , especially those dem and s associated with collisions and repeated high-intensity efforts , were not well matched by those observed in traditional conditioning , repeated high-intensity effort exercise , and skills training activities . Further research is required to investigate whether modifications need to be made to these training activities to better prepare players for the dem and s of National Rugby League competition Background —A classic , unresolved physiological question is whether central cardiorespiratory and /or local skeletal muscle circulatory factors limit maximal aerobic capacity ( & OV0312;o2max ) in humans . Severe heat stress drastically reduces & OV0312;o2max , but the mechanisms have never been studied . Methods and Results —To determine the main contributing factor that limits & OV0312;o2max with and without heat stress , we measured hemodynamics in 8 healthy males performing intense upright cycling exercise until exhaustion starting with either high or normal skin and core temperatures ( + 10 ° C and + 1 ° C ) . Heat stress reduced & OV0312;o2max , 2-legged & OV0312;o2 , and time to fatigue by 0.4±0.1 L/min ( 8 % ) , 0.5±0.2 L/min ( 11 % ) , and 2.2±0.4 minutes ( 28 % ) , respectively ( all P < 0.05 ) , despite heart rate and core temperature reaching similar peak values . However , before exhaustion in both heat stress and normal conditions , cardiac output , leg blood flow , mean arterial pressure , and systemic and leg O2 delivery declined significantly ( all 5 % to 11 % , P < 0.05 ) , yet arterial O2 content and leg vascular conductance remained unchanged . Despite increasing leg O2 extraction , leg & OV0312;o2 declined 5 % to 6 % before exhaustion in both heat stress and normal conditions , accompanied by enhanced muscle lactate accumulation and ATP and creatine phosphate hydrolysis . Conclusions —These results demonstrate that in trained humans , severe heat stress reduces & OV0312;o2max by accelerating the declines in cardiac output and mean arterial pressure that lead to decrements in exercising muscle blood flow , O2 delivery , and O2 uptake . Furthermore , the impaired systemic and skeletal muscle aerobic capacity that precedes fatigue with or without heat stress is largely related to the failure of the heart to maintain cardiac output and O2 delivery to locomotive muscle In order to compare the effectiveness of a daily to an intermittent acclimation protocol , 14 competitive rowers ( mean + /- SD VO2peak = 48 + /- 7 ml x kg x min(-1 ) ) were r and omly assigned to either a consecutive ( 10 consecutive days ) or intermittent acclimation group ( 10 sessions over 3 weeks ) . For every heat exposure , subjects in each group exercised for 30 min at 70 % VO2peak in an environmental chamber set at 38 degrees C and 70 % relative humidity .  Acclimation state was monitored by measuring heart rate ( HR ) , rectal and skin temperature ( Tre and Tsk ) , ratings of perceived exertion ( RPE ) and whole body sweat rate ( SR ) during each heat exposure . Final exercise Tre decreased significantly by 0.6 + /- 0.7 degrees C with intermittent heat exposure but the decrease was significantly larger ( p < 0.05 ) with consecutive day heat exposure ( 1.0 + /- 0.1 degrees C ) . Final exercise HR also decreased significantly by 13 + /- 12 bpm ( p < 0.05 ) in the consecutive group , and non-significantly by 5 + /- 13 bpm in the intermittent group . RPE decreased with daily ( 5 + /- 1 , p < 0.05 ) but did not significantly decrease with intermittent heat exposure ( 1 + /- 3 ) . Similarly , Tsk significantly decreased with consecutive ( 0.4 + /- 0.2 degrees C , p < 0.05 ) but not intermittent exposure ( 0.2 + /- 0.3 degrees C ) and SR did not change in either group . Minimal adaptation occurs with intermittent heat exposure and it appears that daily heat exposure is the most effective acclimation strategy We tested the hypothesis that local sweat rates would not display a systematic postadaptation redistribution toward the limbs after humid heat acclimation . Eleven nonadapted males were acclimated over 3 wk ( 16 exposures ) , cycling 90 min/day , 6 days/wk ( 40 degrees C , 60 % relative humidity ) , using the controlled-hyperthermia acclimation technique , in which work rate was modified to achieve and maintain a target core temperature ( 38.5 degrees C ) . Local sudomotor adaptation ( forehead , chest , scapula , forearm , thigh ) and onset thresholds were studied during constant work intensity heat stress tests ( 39.8 degrees C , 59.2 % relative humidity ) conducted on days 1 , 8 , and 22 of acclimation . The mean body temperature ( Tb ) at which sweating commenced ( threshold ) was reduced on days 8 and 22 ( P < 0.05 ) , and these displacements paralleled the resting thermoneutral Tb shift , such that the Tb change to elicit sweating remained constant from days 1 to 22 . Whole body sweat rate increased significantly from 0.87 + /- 0.06 l/h on day 1 to 1.09 + /- 0.08 and 1.16 + /- 0.11 l/h on days 8 and 22 , respectively . However , not all skin regions exhibited equivalent relative sweat rate elevations from day 1 to day 22 . The relative increase in forearm sweat rate ( 117 + /- 31 % ) exceeded that at the forehead ( 47 + /- 18 % ; P < 0.05 ) and thigh ( 42 + /- 16 % ; P < 0.05 ) , while the chest sweat rate elevation ( 106 + /- 29 % ) also exceeded the thigh ( P < 0.05 ) . Two unique postacclimation observations arose from this project . First , reduced sweat thresholds appeared to be primarily related to a lower resting Tb , and more dependent on Tb change . Second , our data did not support the hypothesis of a generalized and preferential trunk-to-limb sweat redistribution after heat acclimation This study determined the influence of exercise intensity , protective clothing level , and climate on physiological tolerance to uncompensable heat stress . It also compared the relationship between core temperature and the incidence of exhaustion from heat strain for persons wearing protective clothing to previously published data of unclothed persons during uncompensable heat stress . Seven heat-acclimated men attempted 180-min treadmill walks at metabolic rates of approximately 425 and 600 W while wearing full ( clo = 1.5 ) or partial ( clo = 1.3 ) protective clothing in both a desert ( 43 degrees C dry bulb , 20 % relative humidity , wind 2.2 m/s ) and tropical ( 35 degrees C dry bulb , 50 % relative humidity , wind 2.2 m/s ) climate . During these trials , the evaporative cooling required to maintain thermal balance exceeded the maximal evaporative capacity of the environment and core temperature continued to rise until exhaustion from heat strain occurred . Our findings concerning exhaustion from heat strain are 1 ) full encapsulation in protective clothing reduces physiological tolerance as core temperature at exhaustion was lower ( P < 0.05 ) in fully than in partially clothed persons , 2 ) partial encapsulation results in physiological tolerance similar to that reported for unclothed persons , 3 ) raising metabolic rate from 400 to 600 W does not alter physiological tolerance when subjects are fully clothed , and 4 ) physiological tolerance is similar when subjects are wearing protective clothing in desert and tropical climates having the same wet bulb globe thermometer . These findings can improve occupational safety guidelines for human heat exposure , as they provide further evidence that the incidence of exhaustion from heat strain can be predicted from core temperature UNLABELLED Cricketers are often required to play in hot/humid environments with little time for heat adaptation . PURPOSE We examined the effect of a short 4-d hot/humid acclimation program on classical physiological indicators of heat acclimation . METHODS Male club cricketers were r and omly assigned into  heat acclimation ( ACC , n = 6 ) or control ( CON , n = 6 ) groups , and 30 min treadmill trials ( 10 km/h , approx . 30 ± 1.0 ° C , approx . 65 ± 6 % RH ) were conducted at baseline and postacclimation . The ACC group completed four high intensity ( 30 - 45 min ) acclimation sessions on consecutive days at approx . 30 ° C and approx . 60 % RH using a cycle ergometer . The CON group completed matched cycle training in moderate conditions ( approx . 20 ° C , approx . 60 % RH ) . Physiological measures during each treadmill trial included heart rate ; core and skin temperatures ; sweat Na+ , K+ and Cl- electrolyte concentrations ; and sweat rate . RESULTS After the 4-d intervention , the ACC group had a moderate decrease of -11 ( 3 to -24 beats/min ; mean and 90 % CI ) in the 30 min heart rate , and moderate to large reductions in electrolyte concentrations : Na+ -18 % ( -4 to -31 % ) , K+ -15 % ( 0 to -27 % ) , Cl- -22 % ( -9 to -33 % ) . Both ACC and CON groups had only trivial changes in core and skin temperatures and sweat rate . After the intervention , both groups perceived they were more comfortable exercising in the heat . The 4-d heat intervention had no detrimental effect on performance . CONCLUSIONS Four 30 - 45 min high intensity cycle sessions in hot/humid conditions elicited partial heat acclimation . For full heat acclimation a more intensive and extensive ( and modality-specific ) acclimation intervention is needed for cricket players Abstract The aim of this study was to determine the effect of 10 days of heat acclimation with and without pre-cooling on intermittent sprint exercise performance in the heat . Eight males completed three  intermittent cycling sprint  protocol s before and after 10 days of heat acclimation . Before acclimation , one sprint protocol was conducted in control conditions ( 21.8 ± 2.2 ° C , 42.8 ± 6.7 % relative humidity ) and two sprint protocol s in hot , humid conditions ( 33.3 ± 0.6 ° C , 52.2 ± 6.8 % relative humidity ) in a r and omized order . One hot , humid condition was preceded by 20 min of thigh pre-cooling with ice packs ( −16.2 ± 4.5 ° C ) . After heat acclimation , the two hot , humid sprint protocol s were repeated . Before heat acclimation , peak power 
    Output:
    
The review identified aerobic-based tests of performance benefit from STHA training .
Peak anaerobic power efforts have not been demonstrated to improve .
Conclusions The review identified that aerobic-based tests of performance benefit from STHA training .
This is possibly through a number of cardiovascular , thermoregulatory , and metabolic adaptations improving the perception of effort and fatigue through a reduction in anaerobic energy release and elevation of the anaerobic threshold .
STHA training can be applied in the team-sport environment during a range of instances within the competitive season .
A mixed high-intensity protocol may only require five sessions with a duration of 60 min to potentially improve aerobic-based performance in trained athletes