***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: The physiological adaptations to sauna bathing could enhance endurance performance . We have therefore performed a cross-over study in which six male distance runners completed 3 wk of post-training sauna bathing and 3 wk of control training , with a 3 wk washout . During the sauna period , subjects sat in a humid sauna at 89.9+/-2.0 degrees C ( mean+/-st and ard deviation ) immediately post-exercise for 31+/-5 min on 12.7+/-2.1 occasions . The performance test was a approximately 15 min treadmill run to exhaustion at the runner 's current best speed over 5 km . The test was performed on the 1st and 2nd day following completion of the sauna and control periods , and the times were averaged . Plasma , red-cell and total blood volume were measured via Evans blue dye dilution immediately prior to the first run to exhaustion for each period . Relative to control , sauna bathing increased run time to exhaustion by 32 % ( 90 % confidence limits 21 - 43 % ) , which is equivalent to an enhancement of approximately 1.9 % ( 1.3 - 2.4 % ) in an endurance time trial . Plasma and red-cell volumes increased by 7.1 % ( 5.6 - 8.7 % ) and 3.5 % ( -0.8 % to 8.1 % ) respectively , after sauna relative to control . Change in performance had high correlations with change in plasma volume ( 0.96 , 0.76 - 0.99 ) and total blood volume ( 0.94 , 0.66 - 0.99 ) , but the correlation with change in red cell volume was unclear ( 0.48 , -0.40 to 0.90 ) . We conclude that 3 wk of post-exercise sauna bathing produced a worthwhile enhancement of endurance running performance , probably by increasing blood volume 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 Acclimation in a hot environment is one potent means to decrease the heat strain of work in a hot environment . However , with diminished heat exposure , positive adaptations of acclimation may be lost . This rate of loss is equivocal and , once established , could be used to prescribe the time for re-acclimation . The purpose of this study was to determine the rate of loss of heat acclimation over a period of 6 weeks and determine the time needed for re-acclimation after 2 weeks and 4 weeks of de-acclimation in ten healthy participants . All participants first underwent an initial acclimation period ( a 3-day plateau in Tre was used to signify acclimation ) . Based on the mean time to acclimate in Phase 1 ( mean time to acclimate = 6.1±1.4 days ) , the loss of acclimation was mapped and participants were r and omly assigned to one of two groups : one that underwent one 2-hr heat exposure at 1 , 3 , and 5 weeks post-acclimation , and one that underwent one 2-hr heat exposure session at 2,4 , and 6 weeks . Complete loss of acclimation occurred in 6 weeks and , as expected , work HR and Tre increased with increasing time away from the heat ( p<0.05 ) . Based on the time for total loss of acclimation from Phase 1 , participants in Phase 2 ( n = 8) first underwent acclimation . Then , after either a 2-week or 4-week absence from the heat , participants returned to the laboratory for re-acclimation . While not statistically significant yet practically significant ( p = 0.18 ; one-tailed confidence interval ) , average days for re-acclimation in the 2-week group tended to be fewer than in the 4-week group ( days for re-acclimation = 3.8 ± 1.2 and 5.3 ± 1.9 , respectively ) . Based on these general trends , for occupational setting s , a re-acclimation period of 4 days is recommended after 2 weeks absence from the heat , 5 days for 4 weeks absence from the heat , and complete acclimation ( 6 days ) after 6 weeks absence or more from the heat 
    Output:
    
The adaptations in Tc during the HA period were more sustainable when the daily heat exposure duration was increased and heat exposure intensity decreased .
The decay in SR was not related to the number of decay days .
However , protracted HA-regimens seem to induce longer-lasting adaptations in SR .
High heat exposure intensities during HA seem to evoke more sustained adaptations in SR than lower heat stress .
HRA was 8–12 times faster than HAD at inducing adaptations in HR and Tc , but no differences could be established for SR .
Conclusions HAD and HRA differ considerably between physiological systems .
Five or more HA days are sufficient to cause adaptations in HR and Tc ; however , extending the daily heat exposure duration enhances Tc adaptations .
For every decay day , ~ 2.5 % of the adaptations in HR and Tc are lost .
For SR , longer HA periods are related to better adaptations .
High heat exposure intensities seem beneficial for adaptations in SR , but not in Tc .
HRA induces adaptations in HR and Tc at a faster rate than HA .
HRA may thus provide a practical and less disruptive means of maintaining and optimizing HA prior to competition