The Use of a Just Noticeable Difference Approach to Improve Perceptual Acuity Ability in Male Runners.

We were interested in micro-variations in an athlete's psychophysical state that separate peak exertion from physiological collapse. Thus, we measured perceptual acuity in runners using a classic psychophysical approach, the just noticeable difference (JND) on two standard stimuli runs at treadmill speed corresponding to 70%VO2max and 80%VO2max. Thirty-four male runners (M age = 35.26, SD = 7.33 years) first performed a maximal treadmill test to determine the speed of a standard exercise bout for the JND trials. The JND trials consisted of four 5-minute running bouts on a treadmill with 5-minute rests between bouts. For bouts 1 and 3, participants ran at the standard stimuli pace, but for bouts 2 and 4, they adjusted their speeds to achieve a level of exertion at a JND above/below the SS. They achieved differences in the final 30 seconds of the VO2 between each JND bout and the previous standard stimuli at just above (JND-A) and just below (JND-B) the JND perceived exertions. We used a Generalized Linear Model analysis to compare the JND-A and JND-B within and between ventilatory threshold groups (lower/higher) in absolute and relative VO2 and in terms of the total JND magnitude. The magnitude of JND-A was greater than that of JND-B at 70%VO2max and 80%VO2max in absolute units (70%VO2 Δ = 2.62; SE = 0.37; p < .001; 80%VO2 Δ = 1.67; SE = 0.44; p = .002) and in relative units (70%VO2max Δ = 4.70; SE = 0.66; p < .001; 80%VO2max Δ = 2.96; SE = 0.80; p = .002). The total magnitude was greater in the 70%VO2max trial than 80%VO2max in absolute units (70%VO2 M = 3.78, SE = 0.31 mL·kg-1·min-1; 80%VO2 M = 2.62, SE = 0.37 mL·kg-1·min-1; p = .020) and in relative units (70%VO2max M = 6.57, SE = 0.53%VO2max; 80%VO2max M = 4.71, SE = 0.64%VO2max; p = .030). The JND range narrowed when physiologic demand increased, for both physical (speed) and psychological (RPE) variables.

Validity of Weekly and Monthly Perceived Exertion in Runners.

The development of the rating of perceived exertion (RPE) enables the easy assessment of runners' training strain as well as training load (TL). However, the long-term and retrospective validity of TL assessment using RPE scales still needs further investigation. Therefore, this study examined the validity of weekly and monthly ratings of perceived exertion (W-RPE, M-RPE) in assessing TL in runners. Healthy adult runners (n=53) rated perceived exertion using the modified category-ratio 10 (CR-10) scale for each week of a four-week period, as well as for the month, considering the four-week period. CR-10 for the week and the month were multiplied by the total training time of the week and month, respectively, to assess the W-RPE and M-RPE. Training impulse (TRIMP) was used as the criterion measure. The results indicated that the W-RPE and M-RPE may be used for monitoring TL during prolonged periods, presenting a very large correlations with the criterion measure.

The Influence of L-menthol on Time Trial Running Performance in Recreational Runners.

Purpose: This study investigated the effects of combined mouth rinse and topical application of L-menthol on perceptual responses and running performance under thermoneutral conditions (22 ± 2°C and 30-60% relative humidity). Methods: Twelve recreational male runners (age: 31.7 ± 3.8 years; age range: 27-39 years) completed a familiarization, a control test (CON) and two maximal 10-km time trials (counterbalanced randomized crossover design) performed in different days with a non-thermal cooling intervention (combined application of a L-menthol mouth rinse and topical L-menthol gel - MEN) or placebo (PLA). Performance and perceptual measures (thermal sensation, thermal comfort, ratings of perceived exertion and affective response) were recorded for every km completed in the 10-km test. Results: Performance time was lower in MEN (P = 0.03) and PLA (P = 0.003) compared to CON, but no differences were found between MEN vs PLA (P = 1.00). All perceptual responses increased over time in all conditions (P < 0.0001), but only the thermal sensation was lower (P = 0.01) in the MEN compared to CON. Conclusion: L-menthol strategies promote fresh sensations and may improve running performance in 10-km time trial in recreational runners, but the performance improvement could mainly be due to a placebo effect.

Effect of Test Sequence on Maximal Anaerobic and Aerobic Power Achievements in Adults.

The purpose of this study was to examine the effect of test sequence on adults' ability to achieve maximal aerobic and anaerobic power during a single assessment visit. Forty-one adults (24 men, 17 women; 22.0 ± 1.8 years) completed two baseline visits in randomized order consisting of either a maximal oxygen consumption (V̇O2max) or Wingate anaerobic test (WAnT). The subsequent experimental visit consisted of both V̇O2max and WAnT in randomized order separated by 20 minutes of rest. Mixed-model ANOVAs compared baseline and experimental performance between and within groups. Chi Squared Goodness of Fit tests determined if test sequence significantly affected V̇O2max criteria achievement. Significant interaction effects were observed for relative V̇O2max (p = 0.005), RER (p < 0.001), and exercise time (p = 0.022). Within WAnT/V̇O2max subjects, these values significantly decreased from baseline to experimental tests. No differences were found for WAnT values. During the experimental session, 50% of subjects who performed WAnt/V̇O2max and 81% of subjects who performed V̇O2max/WAnT achieved a valid V̇O2max. Chi squared analysis found the change to be significant in WAnT/V̇O2max subjects only. Therefore, performing the WAnT before V̇O2max sequence significantly reduced the percent of subjects who achieved V̇O2max criteria. These findings indicate that the sequence of V̇O2max testing before a WAnT allowed maximal results similar to expected baseline values.

Relative Age Effect in Collegiate Soccer: Influence of Nationality, Playing Position, and Class.

Hurley, E, Comstock, BA, Haile, L, and Beyer, KS. Relative age effect in collegiate soccer: influence of nationality, playing position, and class. J Strength Cond Res 33(12): 3295-3301, 2019-The purpose of this study was to evaluate the existence of relative age effects (RAEs) in collegiate soccer. In addition, the impact of nationality, position, class, and National Collegiate Athletic Association (NCAA) tournament qualification status on the prevalence of RAEs was assessed. Birth dates from male NCAA Division I soccer athletes (n = 4,082) from the 2017/2018 season were categorized into quarters based on calendar and scholastic quarters. All athlete birth-date distributions were compared with the expected birth-date distributions for the United States. International-born athletes (INT) displayed a significant difference in birth-date distribution when assessed with calendar quarters, whereas American-born athletes (USA) showed a significant difference in birth-date distributions when assessed with scholastic quarters. Furthermore, INT showed significant RAEs for midfielders and defenders, whereas USA showed significant RAEs midfielders and goalkeepers. In terms of class, INT had significant RAEs for all classes, whereas USA had significant RAEs only for freshmen and sophomores. All INT had significant RAEs regardless of tournament qualification status; however, USA had significant RAEs only for nontournament teams. In summary, significant RAEs exist in male Division I college soccer; however, the presence of RAEs is influenced by nationality, position, class, and NCAA tournament qualification status. Coaches should be aware of RAEs during the recruitment process to avoid potential selection bias.

Affective and metabolic responses to self-selected intensity cycle exercise in young men.

Self-selected intensity exercise has resulted in greater affective responses (AR) compared to prescribed exercise of similar intensity and many individuals self-select intensity at a moderate level identified by metabolic analysis. As such, self-selected intensity may be an effective alternative for exercise prescription designed to promote adherence and result in health and fitness benefits. Self-selected intensity has not been well described for many subject populations and exercise modes. Therefore, the purpose of this investigation was to measure affective and metabolic responses during self-selected intensity cycle exercise in college-aged men. Thirty-three men (22.4 ±â€¯2.2 yr) performed a peak oxygen consumption test and a 20 min self-selected trial on a cycle ergometer on separate days. Oxygen consumption (VO2) was measured continuously throughout both exercise sessions. AR were measured using the Feeling Scale and ratings of perceived exertion (RPE) using the OMNI Scale every 5 min during the self-selected trial. χ2 analysis was used to determine if a significant proportion of subjects self-selected intensity above 50% VO2 reserve (VO2R), defined as a threshold for moderate-intensity exercise and potential cardiorespiratory fitness benefits by American College of Sports Medicine. Mean self-selected intensity was 57.6 ±â€¯11.1%VO2peak and 89.3 ±â€¯20.2% of ventilatory threshold. Twenty eight of 33 subjects self-selected intensity above 50% VO2R (p < .05). Self-selected intensity was associated with positive AR (1.8 ±â€¯1.4) and mean RPE of 4.0 ±â€¯1.5. In college-aged men, self-selected intensity cycle exercise was performed at a moderate intensity level and elicited positive AR for most subjects. Therefore, self-selected intensity could be an effective component of an exercise prescription for this population.

Validation of the OMNI Scale of Thermal Sensations.

Concurrent and construct validation of the OMNI Scale of Thermal Sensations was examined in a sample of 16 adult men and 5 adult women. Concurrent validity was established by regressing OMNI ratings of thermal sensation against core and skin temperatures obtained during treadmill walking while wearing firefighter thermal-protective clothing in temperatures between 33 and 35 degrees C. Construct validity was established by regressing the OMNI scale against a construct-specific visual analogue scale. OMNI scale responses accounted for statistically significant variance in both skin temperature and core temperature (48% and 51%, respectively) and visual analogue scale responses (84%). Concurrent and construct validity were established for the OMNI Scale of Thermal Sensations in healthy adults performing treadmill walking while wearing fire fighter thermal protective clothing.

Session perceived exertion and affective responses to self-selected and imposed cycle exercise of the same intensity in young men.

Session perceived exertion (S-RPE) and session affective responses (S-AR) are post-exercise estimates of the global responses experienced during exercise. To compare S-RPE and S-AR to acute RPE (A-RPE) and acute AR (A-AR) during self-selected (SS) and imposed (IMP) exercise of the same workload. Thirty-two males (22.3 ± 2.2 years) performed two, 20-min cycle exercise trials. In the SS trial, subjects adjusted SS workload every 5 min. In the IMP trial, workload was automatically adjusted to the SS workload. Experimental (EXP, n = 16) subjects were unaware that workload was the same between the trials. Control (CON, n = 16) subjects were aware that both trials were of the same workload. A-RPE and A-AR were measured every 5 min using the OMNI Scale and Feeling Scale, respectively. Fifteen minutes following a cool-down, subjects rated S-RPE and S-AR. Session and exercise values were compared between trials and groups using ANOVA. No between-group differences were observed. There were no differences between the SS and IMP trials for S-RPE, A-RPE, S-AR and A-AR. For SS and IMP trials, S-RPE was greater than A-RPE (4.6 ± 1.5 vs. 3.9 ± 1.4; 4.3 ± 1.6 vs. 3.7 ± 1.4, respectively, p < 0.05). S-AR was greater than A-AR for the SS trial (1.9 ± 1.3 vs. 2.3 ± 1.5, p < 0.05), but not the IMP trial (1.9 ± 1.5 vs. 2.2 ± 1.4). A mismatch exists between the session and acute exercise values for RPE and AR during the SS cycle exercise in young males.

Just noticeable difference in perception of physical exertion during cycle exercise in young adult men and women.

The purpose of this investigation was to describe the just noticeable difference (JND) in perceived exertion during cycle exercise. Males (n = 20) and females (n = 26) (21.4 ± 3.1 year) performed load-incremented cycle exercise to peak intensity. At the end of each minute, subjects rated their overall-body perceived exertion using the OMNI (0-10) rating of perceived exertion (RPE) scale. Individual regression derived the power output (PO) corresponding to RPE 5. This PO served as the standard stimulus (SS). On a separate occasion, four 5-min cycling bouts were performed with 5 min rest between bouts. During bouts 1 and 3 subjects cycled at the SS. During bouts 2 and 4 subjects adjusted the resistance to achieve a level of exertion just noticeably above/below the SS. The difference in final 30-s oxygen consumption (VO2) and PO between each JND bout and the previous SS were the above (JND-A) and below (JND-B) perceived exertion JNDs. JND-A and JND-B were compared between genders and between subjects exhibiting lower versus higher ventilatory threshold (VT) and VO(2PEAK) within genders for VO2 (l · min(-1), %VO(2PEAK)) and PO (W, %SS). JND-B was significantly (P < 0.05) greater than JND-A for VO2 and PO, when expressed in absolute (l · min(-1), W) and relative units (%VO(2PEAK), %SS). Males exhibited greater JND values than females in absolute, but not relative, units. Subjects with lower and higher VT and VO(2)PEAK exhibited similar JND values. The JND can serve as an effective tool to measure perceptual acuity and to determine individual ability to self-regulate prescribed exercise intensities.

Exercise intensity self-regulation using the OMNI scale in children with cystic fibrosis.

Prescribing exercise at intensities that improve fitness is difficult in children with cystic fibrosis (CF) due to ventilatory limitations and fluctuating health status. Our aim was to determine if children with CF could regulate the intensity of cycle ergometer and treadmill exercise using target ratings of perceived exertion (RPE) derived from the Children's OMNI Scale. We examined prescription congruence (similar oxygen consumption [VO2] and heart rate [HR] for target RPE) and intensity discrimination (different VO2 and HR for different RPEs), from cycle to cycle and cycle to treadmill. Subjects were 24 children (12 male, 12 female), aged 10-17 years with varying disease severity. Each child participated in one orientation, one estimation trial (graded maximal exercise test), and two production trials (cycle and treadmill, alternating between RPE 4 and 7). At RPE 4, congruence was evident for both VO2 and HR on the treadmill. On the cycle at RPE 4, VO2 was significantly higher only in the first production trial, although HRs tended to be higher in the production trials than the estimation trial. Prescription congruence was also supported at RPE 7, with no significant differences in VO2 or HR between estimation and production trials on cycle or treadmill. Results fully supported intensity discrimination, with significant differences between VO2 and HR at RPE 4 and 7 (P < 0.0001). Children with CF appear capable of using the OMNI Scale to regulate cycle and treadmill exercise intensity. Training using this methodology has the potential to promote fitness in children with CF of varying severity.

Use of ratings of perceived exertion to anticipate treadmill test termination in patients taking beta-blockers.

This investigation identified a perceptually-based "warning zone" that can be used to anticipate termination of treadmill tests administered to individuals taking beta-blockers. The use of ratings of perceived exertion to anticipate test termination may be valuable given the attenuation of heart rate associated with the use of this class of medication. Sixteen men with coronary artery disease participated in this investigation. Ratings of perceived exertion (Borg 6-20 Scale) were estimated during the last 15 sec. of each minute of a progressively incremented treadmill test. Tests were terminated when participants indicated they were too fatigued to continue. The time-to-test termination was determined from the point that participants estimated a rating of 10, 11, 12, 13, 14, 15, 16, and 17 in order to determine the rating that was less than or equal to the time associated with a single exercise stage. A rating of 14 was associated with impending termination, which can be used as a "warning zone." The time to termination corresponding to a rating of 14 was 153.1 sec. (SD = 27.0). Participants exercised for 153.1 sec. (SE = 27.0) after estimating a rating of 14. Once a rating of 14 is reached, volitional test termination will occur before the next exercise stage is completed.

The effects of 12 weeks of step aerobics training on functional fitness of elderly women.

The purpose of this study was to determine the effects of 12 weeks of step aerobics (SA) training on the functional fitness of apparently healthy older women. Thirteen previously sedentary elderly women (mean age 63.14 years) participated in this study. Subjects performed 3 training sessions per week for 30-60 minutes per session. All measurements were assessed at baseline, after 12 weeks of training (posttest), and after 1 month of detraining. Assessments included the evaluation of body mass index (BMI), waist circumference (WC), strength of the upper (arm-curl [AC] test) and lower body (30-second chair-stand test [CS]), dynamic balance and agility (8 foot up and go [8 ft]), flexibility (chair sit-and-reach [CSR]), and cardiorespiratory fitness (6-minute walk test [6MW]). Step aerobics significantly improved all functional fitness components except for BMI. The 12 weeks of SA promoted a large effect size in the following measurements: WC (d = 1.6); CSR (d = 1.51); CS (d = 1.49); AC (d = 1.41); 8 ft (d = 1.32); and 6MW (d = 1.06) (p < 0.05). These results indicate that 12 weeks of SA had a positive effect on the functional fitness components of these older women. Furthermore, these findings were confirmed by the reverse effect observed after 1 month of detraining, except for upper body strength (AC test). In conclusion, 12 weeks of SA training can promote improvements in the functional fitness of apparently healthy older women. Therefore, SA can be considered an effective exercise modality to prevent the loss of functional fitness and its associated consequences.

Identification of a rating of perceived exertion-based warning zone to anticipate graded treadmill test termination.

The purpose of this investigation was to identify a perceptually based warning zone to anticipate termination of Bruce treadmill tests. Apparently healthy adult women (n = 116) and men (n = 55) participated. The time to test termination was measured from the point during the treadmill test at which participants estimated a rating of perceived exertion of 12, 13, 14, 15, 16, and 17 using the Borg 6-20 scale to specify the rating of perceived exertion which was less than or equal to one exercise test stage. Women exercised for 141.9 +/- 99.2 sec. after reporting a rating of perceived exertion of 14. Men terminated the treadmill test 120.1 +/- 80.0 sec. after estimating their rating of perceived exertion to be 15, indicating volitional test termination will occur before the next exercise stage is completed. Accurate and timely prediction of test termination using ratings of perceived exertion may enhance the safety of exercise tests administered to apparently healthy adults and facilitate obtaining endpoint measures upon which to prescribe exercise intensity.

A comparison of functional fitness of older Brazilian and American women.

The purpose of this cross-sectional study was to generate a functional-fitness profile for older women from the south of Brazil and to compare their functional profile with an age-matched cohort of American women. The Fullerton Functional Fitness Test (body-mass index, 6-min-walk test, chair sit-and-reach, chair stand, arm curl, and 8-ft up-and-go) was administered to 1,033 participants. Z scores indicate that older American women performed better in all functional tests than age-matched Brazilians. This fact could be explained by the delayed establishment of specific health policies for older adults in Brazil. In conclusion, the findings provide guidelines about the normal variation of functional fitness in older women from the southern region of Brazil. In addition, these data can be used to help identify older women with functional losses, thereby assisting in the diagnosis of early disability.