Omni Scale Rating of Perceived Exertion at Ventilatory Breakpoint by Direct Observation of Children's Kinematics

Which Factors Influence Running Gait in Children and Adolescents? A Narrative Review

In recent years, running has dramatically increased in children and adolescents, creating a need for a better understanding of running gait in this population; however, research on this topic is still limited. During childhood and adolescence multiple factors exist that likely influence and shape a child's running mechanics and contribute to the high variability in running patterns. The aim of this narrative review was to gather together and assess the current evidence on the different factors that influence running gait throughout youth development. Factors were classified as organismic, environmental, or task-related. Age, body mass and composition, and leg length were the most researched factors, and all evidence was in favour of an impact on running gait. Sex, training, and footwear were also extensively researched; however, whereas the findings concerning footwear were all in support of an impact on running gait, those concerning sex and training were inconsistent. The remaining factors were moderately researched with the exception of strength, perceived exertion, and running history for which evidence was particularly limited. Nevertheless, all were in support of an impact on running gait. Running gait is multifactorial and many of the factors discussed are likely interdependent. Caution should therefore be taken when interpreting the effects of different factors in isolation.

Examination of Coach and Player Perceptions of Recovery and Exertion

Kraft, JA, Laurent, ML, Green, JM, Helm, J, Roberts, C, and Holt, S. Examination of coach and player perceptions of recovery and exertion. J Strength Cond Res 34(5): 1383-1391, 2020-Monitoring training and recovery are essential for exercise programming. Athletes can validly assess training load (TL) via the session rating of perceived exertion (SRPE) technique. However, it is unclear if coaches can successfully use this model. This study compared coach and athlete perceptions of effort and recovery, and it evaluated the efficacy of perceptually based TL monitoring. Participants included 56 athletes (Women's volleyball, soccer, and basketball and Men's basketball) and their coaches (n = 4). Perceived recovery was estimated via the Perceived Recovery Status scale. Scores of TL were calculated using the Edward's heart rate (HR) method and by multiplying SRPE by duration. Coaches provided an intended SRPE (SRPE-CI) before practice. Also, SRPE was independently estimated by coaches (SRPE-CO) and athletes (SRPE-A) ∼15-20 minutes after practice. Paired t-tests and Pearson's correlations were applied to make comparisons (α ≤ 0.05). Values of SRPE-CI, SRPE-CO, SRPE-A TLs were strongly correlated with Edwards' HR-based TLs (R = 0.74, 0.73, and 0.76, respectively). However, SRPE-CI (5.5 ± 1.9) and SRPE-CO (5.0 ± 1.9) was higher than SRPE-A (4.5 ± 1.9). Coaches estimated recovery higher than athletes (7.1 ± 1.3 vs. 5.8 ± 1.6). Estimates of TL strongly correlated with Edwards' TL regardless of information source (coach or athlete) or time point (SRPE-CI TL or SRPE-CO TL). Results suggest that coaches' perceptions validly indicated TL. Coaches' perceptions provide parallel information (correlated strongly with Edwards TL) but not identical information (demonstrated by differences in SRPE) as athlete perceptions. Differences in perceived recovery indicate that coaches overestimate recovery when compared with athletes' perceptions.

Development of a perceived exertion scale for dogs using selected physiologic parameters

OBJECTIVE

To develop a perceived exertion scale for dogs exercising on a treadmill and to assess intra- and inter-observer variability.

MATERIALS AND METHODS

Fifteen healthy client-owned dogs participated in paired exercise trials. Measurements of lactate, glucose, heart rate, temperature, respiratory rate and regional tissue oximetry were obtained before, during and after exercise. Perceived exertion scale scores were recorded during exercise and using video recordings to evaluate inter-observer variability. Correlations were evaluated using the Spearman's non-parametric method.

RESULTS

Thirteen dogs completed both trials. Dogs walked or trotted on the treadmill with an average perceived exertion score of 2 in both trials. Holter heart rate was positively correlated with perceived exertion scale scores from all observers for both trials. In trial 1, plasma glucose decreased in association with increase in perceived exertion and, in trial 2, cutaneous oximetry decreased, respiratory rate increased and temperature increased with increases on the perceived exertion scale. Inter-observer perceived exertion scale scores were positively correlated in both trials. There was no intra-observer variability between trials.

CLINICAL SIGNIFICANCE

The perceived exertion scale correlated with the measured physiologic parameters in dogs exercising at mild to moderate intensity. The perceived exertion scale was consistent and repeatable but larger study numbers and further validation are needed before it can be widely applied.

Structured home-based exercise program for improving walking ability in ambulant children with cerebral palsy

OBJECTIVE

To investigate outcomes after 8 weeks of a structured home-based exercise program (SHEP) for improving walking ability in ambulant children with cerebral palsy (CP).

METHOD

Eleven children participated in this study (7 males and 4 females, mean age 10 years 3 months, standard deviation (SD) 3y) with Gross Motor Function Classification System (GMFCS) I-III. This study used a prospective multiple assessment baseline design to assess the effect of SHEP upon multiple outcomes obtained in three different phases. Exercise intensity was quantified by OMNI-RPE assessed by caregivers and children. Outcome assessments of walking speed, GMFM-66 and physiological cost index (PCI) were measured four times at pre-intervention (Phase 1) and at 3-weekly intervals over eight weeks during intervention (Phase 2). Follow-up assessments were performed at one month and three months after intervention (Phase 3). Statistical analyses were repeated measures ANOVA and Wilcoxon signed-rank test.

RESULTS

SHEP improved walking ability in children with CP, particularly for their walking speed (p= 0.01, Cohen's d= 1.9). The improvement of GMFM-66 scores during Phase 2 and Phase 3 had a large effect size, with Cohen's d of 1.039 and 1.054, respectively, compared with that during Phase 1 (p< 0.017). No significant change of PCI was observed (Cohen's d= 0.39).

CONCLUSION

SHEP can be a useful intervention tool, given as a written, structured, and practical exercise program undertaken at home to achieve short term goals for improving walking ability when added to standard care.

Exercise Prescription Using a Group-Normalized Rating of Perceived Exertion in Adolescents and Adults With Spina Bifida

BACKGROUND

People with spina bifida (SB) face personal and environmental barriers to exercise that contribute to physical inactivity, obesity, risk of cardiovascular disease, and poor aerobic fitness. The WHEEL rating of perceived exertion (RPE) Scale was validated in people with SB to monitor exercise intensity. However, the psycho-physiological link between RPE and ventilatory breakpoint (Vpt), the group-normalized perceptual response, has not been determined and would provide a starting point for aerobic exercise in this cohort.

OBJECTIVES

The primary objectives were to determine the group-normalized RPE equivalent to Vpt based on WHEEL and Borg Scale ratings and to develop a regression model to predict Borg Scale (conditional metric) from WHEEL Scale (criterion metric). The secondary objective was to create a table of interchangeable values between WHEEL and Borg Scale RPE for people with SB performing a load incremental stress test.

DESIGN

Cross-sectional observational.

SETTING

University laboratory.

PARTICIPANTS

Twenty-nine participants with SB.

METHODS

Participants completed a load incremented arm ergometer exercise stress test. WHEEL and Borg Scale ratings were recorded the last 15 seconds of each 1-minute test phase.

OUTCOME MEASURES

WHEEL and Borg Scale ratings, metabolic measures (eg, oxygen consumption, carbon dioxide production). Determined Vpt via plots of oxygen consumption and carbon dioxide production against time.

RESULTS

Nineteen of 29 participants achieved Vpt (Group A). The mean ± standard deviation peak oxygen consumption at Vpt for Group A was 61.76 ± 16.26. The WHEEL and Borg Scale RPE at Vpt were 5.74 ± 2.58 (range 0-10) and 13.95 ± 3.50 (range 6-19), respectively. A significant linear regression model was developed (Borg Scale rating = 1.22 × WHEEL Scale rating + 7.14) and used to create a WHEEL-to-Borg Scale RPE conversion table.

CONCLUSION

A significant linear regression model and table of interchangeable values was developed for participants with SB. The group-normalized RPE (WHEEL, 5.74; Borg, 13.95) can be used to prescribe and self-regulate arm ergometer exercise intensity approximating the Vpt.

LEVEL OF EVIDENCE

III.

Observation of Omni Scale of Perceived Exertion during Fire Suppression Training

Ratings of perceived exertion in 66 firefighters before, during, and immediately after performing 20min. of fire suppression training were self-reported by the participants using the OMNI Walk-Run Scale and also recorded by a trained observer. The observer used the same definition of perceived exertion, instructions, and high and low anchoring procedures as the participants. Self-reported and observed ratings of perceived exertion did not differ before or during fire suppression training. Significant differences were noted between the self-reported and observed ratings immediately after fire suppression training. These findings support the use of direct observation to provide estimates of ratings of perceived exertion during fire suppression training.

Effects of supervised exercise program on metabolic function in overweight adolescents

BACKGROUND

Inactivity is a primary factor related to childhood obesity, yet aerobic exercise has been shown to prevent weight gain and improve fitness in adolescents. Moreover, children become less active during their summer break from school. This study compared the effects of 4 and 8 weeks of supervised summer activity versus an unsupervised summer break on metabolic function and fitness in adolescents.

METHODS

Twenty-two adolescents were divided into 4-week (n=6, weight 48.1±14.9 kg, body fat 27.4±8.4%) and 8-week exercise groups (n=6, weight 43.4±10.9 kg, body fat 28.5±12.8%), that performed supervised, play-based physical activity, versus an age-matched 8 week control group that maintained their typical summer break (n=10, weight 41.7±10.0 kg, body fat 23.7±8.0%). Anthropometrics, resting energy expenditure (REE), resting heart rate (RHR) and peak aerobic capacity (VO(2peak)) were evaluated before and after the intervention (4 or 8 weeks).

RESULTS

REE showed group differences in posttraining conditions (the 4-week group vs. the control group, 1220±169 vs. 1067±144 kcal/die, and the 8-week group vs. the control group, 1202±151 vs. 1067±144 kcal/die, P=0.047), but RHR decreased (pre-program vs. post program: 97±22 vs. 80±8 beat/min, P=0.001) and VO(2peak) significantly increased (pre-program vs. post program: 27.8±7.8 vs. 34.8±6.5 mL/kg/min, P=0.001) in the 8-week group compared to the control group.

CONCLUSIONS

Eight weeks of supervised play-based activity increased REE and VO(2peak) in adolescents with concomitant decreases in RHR. These data suggest that this novel model of exercise prescription could be considered world-wide by clinicians to improve fitness base in adolescents and help to combat the growing epidemic of childhood obesity.

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.