***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: Flaws in the design , conduct , analysis , and reporting of r and omised trials can cause the effect of an intervention to be underestimated or overestimated . The Cochrane Collaboration ’s tool for assessing risk of bias aims to make the process clearer and more PURPOSE To establish the typical error ( TE ) associated with equipment , testing , and biological variation of a running economy ( RE ) test in 11 elite male distance runners ( VO2max 70.3 + /- 7.3 mL x min(-1 ) x kg(-1 ) ) , and measure the between-athlete variation of 70 highly trained runners ( VO2max 69.7 + /- 6.0 mL x min(-1 ) x kg(-1 ) ) to determine the magnitude of the smallest worthwhile change ( SWC ) required for RE . METHODS Runners performed three 4-min bouts of submaximal treadmill running at speeds of 14 , 16 , and 18 km x h(-1 ) ( 0 % grade ) , on two separate occasions within a 7-d period to determine reliability and once over a 3-yr period to measure the SWC . During all RE tests O2 consumption ( VO2 ) , ventilation ( VE ) , respiratory exchange ratio ( RER ) , heart rate ( HR ) , stride rate ( SR ) , and concentration of blood lactate ( Lac ) were determined . RESULTS The TE for the pooled data of three running speeds ( 14 , 16 , and 18 km x h(-1 ) ) was 2.4 % for VO2 , 7.3 % for VE , 27 % for Lac , and ranged between 1 and 4 % for RER , HR , and SR . CONCLUSIONS The results demonstrate that although the magnitude of the TE for a submaximal treadmill running protocol of three 4-min work efforts is small ( 2.4 - 7.3 % ) for measures associated with cardiorespiratory parameters , it is three- to fourfold higher for Lac . Given the small TE associated with RE , and a SWC of similar magnitude for this cohort of distance runners , the RE test is useful in detecting changes attributable to training interventions . Changes in RE greater than approximately 2.4 % in this cohort of elite distance runners are likely to be " real " and " worthwhile , " and not simply related to testing error and typical variation We investigated the differences in performance between 100-m sprints performed on a sprint treadmill recently vali date d versus on a st and ard track . To date , studies comparing overground and treadmill running have mainly focused on constant and not maximal “ free ” running speed , and compared running kinetics and kinematics over a limited number of steps , but not overall sprint performance . Eleven male physical education students including two sprinters performed one 100-m on the treadmill and one on a st and ard athletics track in a r and omized order , separated by 30 min .  Performance data were derived in both cases from speed – time relationships measured with a radar and with the instrumented sprint treadmill , which allowed subjects to run and produce speed “ freely ” , i.e. with no predetermined belt speed imposed . Field and treadmill typical speed – distance curves and data of maximal and mean speed , 100-m time and acceleration/deceleration time constants were compared using t tests and field – treadmill correlations were tested . All the performance parameters but time to reach top speed and deceleration time constant differed significantly , by about 20 % on average , between field and treadmill ( e.g. top speed of 8.84 ± 0.51 vs. 6.90 ± 0.39 m s−1 ) . However , significant correlations were found ( r > 0.63 ; P < 0.05 ) for all the performance parameters except time to reach top speed . Treadmill and field 100-m sprint performances are different , despite the fact that subjects could freely accelerate the belt . However , the significant correlations found make it possible to investigate and interpret inter-individual differences in field performance from treadmill measurements Abstract . Modern ergometric equipment enables the simulation of laboratory maximal oxygen uptake ( V˙O2max ) testing in the field . Therefore , it was investigated whether the improved event specificity on the track might lead to higher V˙O2max measurements in running . Identical protocol s were used on the treadmill and on the track ( speed was indicated by a computer-driven flashing light system ) . Ambulatory measurements of gas exchange were carried out throughout both tests , which were executed in r and omized order . There were no significant differences ( P=0.71 ) in V˙O2max between treadmill [ 4.65 ( 0.51 ) ml·min–1 ] and field tests [ 4.63 ( 0.55 ) ml·min–1 ] . However , the test duration differed significantly ( P<0.001 ) by approximately 5 % : treadmill 691 ( 39 ) s ; field test 727 ( 42 ) s. With the exception of maximum heart rate ( HRmax ; significantly higher in the field with P=0.02 ) all criteria for the degree of effort were similar between the two tests . However , the difference in HRmax at less than 2 beats·min–1 , was practically negligible . Submaximal measurements of oxygen uptake and minute ventilation were significantly higher on the treadmill ( P<0.001 for both parameters ) . In summary , field tests with incremental running protocol s do not result in higher V˙O2max measurements compared to laboratory treadmill exercise . A better running economy on the track results in higher maximal velocities and longer exercise duration s being sustained . The determination of V˙O2max is not a reasonable application for ambulatory gas exchange measurements because laboratory values are not surpassed Abstract Outdoor exercise setting s promote greater psychological well-being than synthetic equivalents , although the influence of the exercise context has not been investigated at high exercise intensities . This study compared the psychological effects of high-intensity exercise in outdoor green and indoor gym setting s in 22 adult runners using a r and omized repeated measures design . Affect and perceived exertion were assessed before , during , and after a 6000-m run with the second half completed at maximum effort . Perceived exertion and activation increased in a progressive manner from baseline to 6000 m , and decreased during the 10-min recovery post-run . Non-significant reductions in affective valence were observed between 3000 and 6000 m , followed by a significant increase post-run . Outcomes did not differ at any time point between the setting s. This study suggested that regular runners experience positive affective responses during and after high-intensity exercise in both a natural outdoor environment and an indoor gym Abstract This study aim ed to test the validity of a non-motorised treadmill ( NMT ) for the measurement of self-paced overground endurance running performance . Ten male runners performed r and omised 5-km running time trials on a NMT and an outdoor athletics track . A range of physiological and perceptual responses was measured , and foot strike was classified subjectively . Performance time was strongly correlated ( r = 0.82 , ICC = 0.86 ) between running modes , despite running time being significantly longer on the NMT ( 1264 ± 124 s vs. 1536 ± 130 s for overground and NMT , respectively ; P < 0.001 ) . End blood lactate concentration and rating of perceived exertion were significantly higher on the NMT compared to overground . Integrated electromyography was significantly lower on the NMT for three muscles ( P < 0.05 ) , and mean stride rate was also significantly lower on the NMT ( P = 0.04 ) . Cardiorespiratory responses of heart rate , oxygen uptake and expired air volume demonstrated strong correlations ( r = 0.68–0.96 , ICC = 0.75–0.97 ) and no statistical differences ( P > 0.05 ) . Runners were consistently slower on the NMT , and as such it should not be used to measure performance over a specific distance . However , the strong correlations suggest that superior overground performance was reflected in relative terms on the NMT , and therefore , it is a valid tool for the assessment of endurance running performance in the laboratory The aim of this study was to compare the physiological responses during 15 min of intermittent running consisting of 30 s of high-intensity running exercise at maximal aerobic velocity ( MAV ) interspersed with 30 s of passive recovery ( 30 - 30 ) performed outdoor versus on a motorized treadmill . Fifteen collegiate physically active males ( age , 22 ± 1 years old ; body mass , 66 ± 7 kg ; stature , 176 ± 06 cm ; weekly training volume , 5 ± 2 h·week-1 ) , performed the Fitness Intermittent Test 45 - 15 to determine maximal oxygen uptake ( V̇O2max ) and MAV and then completed in r and om order 3 different training sessions consisting of a 30-s run/30-s rest on an outdoor athletic track ( 30 - 30 Track ) at MAV ; a 30-s run/30-s rest on a treadmill ( 30 - 30 Treadmill ) at MAV ; a 30-s run/30-s rest at MAV+15 % ( 30 - 30 + 15 % MAV Treadmill ) . Oxygen uptake ( V̇O2 ) , time above 90%V̇O2max ( t90%V̇O2max ) , and rating of perceived exertion ( RPE ) were measured during each training session . We observed a statistical significant underestimation of V̇O2 ( 53.1 ± 5.4 mL·kg-1·min-1 vs 49.8 ± 6.7 mL·kg-1·min-1 , -6.3 % , P = 0.012 ) , t90%V̇O2max ( 8.6 % ± 11.5 % vs 38.7 % ± 32.5 % , -77.8 % , P = 0.008 ) , RPE ( 11.4 ± 1.4 vs 16.5 ± 1.7 , -31 % , P < 0.0001 ) during the 30 - 30 Treadmill compared with the same training session performed on track . No statistical differences between 30 - 30 + 15 % MAV Treadmill and 30 - 30 Track were observed . The present study demonstrates that a 15 % increase in running velocity during a high-intensity intermittent treadmill training session is the optimal solution to reach the same physiological responses than an outdoor training session Abstract Heesch , MWS and Slivka , DR . Running performance , pace strategy , and thermoregulation differ between a treadmill and indoor track . J Strength Cond Res 29(2 ) : 330–335 , 2015—Self-paced time trials have long been used as an indicator of running performance . The purpose of this study was to examine if potential physiological and thermoregulatory differences between treadmill and track running would alter performance in a self-paced 10-km time trial . Ten ( n = 10 ) recreationally trained male distance runners ( age : 32 ± 6 years , height : 177 ± 6 cm , body mass : 76 ± 11 kg , % body fat : 14.4 ± 4.5 , : 62.2 ± 9.5 ml·kg−1·min−1 ) completed two 10-km time trials in a r and omized , counterbalanced order on separate days : 1 on a treadmill at 1 % grade ( TM ) , and 1 on a 200-m indoor track ( IT )  . Core temperature , skin temperature , and heart rate ( HR ) were continuously monitored during the run . The ten-kilometer run time was longer during the IT trial ( 41.66 ± 5.86 minutes ) than during the TM trial ( 40.10 ± 6.06 minutes ; p < 0.001 ) , despite a faster first kilometer in the IT trial ( p = 0.029 ) . There were no differences between TM and IT trials in the HR ( 174 ± 13 b·min−1 and 178 ± 13 b·min−1 , respectively ; p = 0.846 ) or body core temperature ( 38.6 ± 0.5 ° C and 38.9 ± 0.5 ° C , respectively , p = 0.218 ) . Skin temperature was higher in the TM trial ( 35.1 ± 2.5 ° C ) than in the IT trial ( 32.7 ± 3.0 ° C ; p = 0.002 ) . These data indicate that performance differences exist between a 10-km time trial performed on a TM vs. an IT , potentially because of differences in pacing strategy or metabolic cost between the 2 conditions 
    Output:
    
HR and RPE during motorised treadmill running were higher at faster submaximal speeds and lower at slower submaximal speeds than during overground running .
Conclusions Some , but not all , variables differ between treadmill and overground running , and may be dependent on the running speed at which they are assessed .