Pace Versus Prediction: Is the Age of the Runner Associated With Marathon Success?

INTRODUCTION: During closed-loop exercise, such as marathon running, the athlete adopts a pacing strategy to optimise performance. Exercise intensity (speed) is modulated in response to afferent signals from biological and psychological systems, which relay the responses of the exercise to the brain where efferent, homeostatic-orientated responses are issued. Thus a conscious perception of effort is continuously compared to a sub-conscious template which is derived from previous exposure to the sensations of pain and fatigue and expected exercise duration. The purpose of this study was to explore the association between pacing strategy/race outcome and biological age of the athlete. METHODS: Following local institutional ethical approval n = 777 runners who were competing in the 2015 London Marathon volunteered and agreed to participate. Age, gender and experience of the participants were ascertained using an online survey and opportunistic questionnaire surveying at the pre-marathon registration event. Age was stratified according to the following classifications: 18-39 yrs, 40-49 yrs, 50-59 yrs and >60 yrs. Additionally, participants were asked to predict their marathon finish time (PT) serving as a proxy for end-point and compared to actual finish time (FT). All participating runners 5km splits and FT were downloaded from the race website, converted to speed and then normalised (%) to the final split time/speed (m∙s-1). RESULTS: Significant differences were observed for all age groups (p 60 yrs (p = 0.153). Non-significant differences observed between age groups across all 5km splits (p > 0.05), but within group differences observed between 10-15km for all age groups (p 60yrs at 30-35km (ES = 0.53). CONCLUSIONS: These data suggest that the biological age of the athlete is associated with the implementation of a successful pacing strategy and may be a function of the accrued training volume and/or emotional-event development. Athletes are encouraged to pace themselves with older (>60yrs) athletes with similar PT’

Pace Versus Prediction: Is the Experience of the Runner Associated With Marathon Success?

PURPOSE: Pacing strategies during exercise are attributed to optimising the balance between the artefacts of fatigue and regulation of substrate metabolism. Pace judgement is set within a continuum of information from the ability to anticipate metabolic demands and select an appropriate strategy through to the accumulation of prior experience for completion of such a task that has a known end-point. Therefore the purpose of this study was to evaluate the importance of athlete experience to successfully regulate pace and attain a predicted end time during a marathon. METHOD: Following local institutional ethical approval n= 777 runners competing in the 2015 London Marathon agreed to participate. Using an on-line survey and opportunistic questionnaire at a pre-marathon event participants were asked to predict their race time. Athlete experience (EXP) was established based on the number of previously completed marathons using a Likert scale from 0 to greater than 10 with increments of 1 race. Athlete age was also recorded. All race data was downloaded from the race website generating 5Km split times, then converted to speed and normalised (%) to the final split time/speed (m.s-1). Prediction time (PT) was used a proxy for end-point and compared to finish time (FT). RESULTS: FT for whole group (WG) was 15479 ±3311s compared to the group PT 15003 ±2972s a significant difference of 476s (P= 0.0001). An R2of 0.863 observed for WG compared to 0.799 (EXP-0) and 0.852 (EXP-5) when comparing FT to PT. Significant differences observed between PT and FT for all EXP groups apart from EXP-5 (P= 0.0001). EXP-0 showed significant difference across all split times apart from 35-40 km (P=0.0001) with a decrease in normalised speed from 5km (109.0 ±7.6) –40km (89.9 ±7.4%). The EXP-5 group showed significant changes in pace between 25-30 km (P= 0.001) (ES= 0.35) and 30-35 km (P= 0.0001) (ES= 0.44), decrease in pace from 5km (105.0 ±5.7%) to 40km (93.7 ±5.6%). CONCLUSIONS: These data suggest that successful marathon pacing is dependent on the experience of the athlete reflecting the development of the pacing template. Additionally experience is associated with better attainment of prediction time suggesting that less experienced runners should run with more experienced athletes with similar end-point targets

Pacing accuracy during an incremental step test in adolescent swimmers

To assess pacing accuracy in a group of adolescent swimmers during an incremental step test. Fifteen well-trained swimmers (age 15±1.5 years; height 170.2±8.8 cm; mass 60.2±6.6 kg), completed two 7×200 m tests, separated by ~72 hours. They swam to a predetermined incrementally increasing pace per step and were instructed to swim at even pace. Upon completion of each step, rating of perceived exertion, heart rate and blood lactate were recorded. Significant differences observed for both trials between actual and predicted swim time (P<0.05). Significant differences also observed between the first and second 100 m of each step in trial 1 for step 1 (P=0.001, effect size [ES] =0.54), step 2 (P=0.0001, ES =0.57), step 4 (P=0.0001, ES =0.53), step 5 (P=0.005, ES =0.65), step 6 (P=0.0001, ES =0.50), and step 7 (P=0.0001, ES =0.70). Similar responses witnessed for trial 2 (P<0.05). Findings suggest that the finite anaerobic capacity was engaged sooner than would normally be anticipated, as a function of an inability to regulate pace. This is proposed to be a consequence of the volume of exposure to the biological and psychological sensations and cognitive developmental status. Given the apparent error in pacing judgment exhibited in this population group, caution should be applied when adopting such tests to monitor training responses with adolescent athletes, and alternate means of modulating pace be investigated

Prior Knowledge of Trial Number Influences the Incidence of Plateau at VO2max

The purpose of this study was to assess the VO2max plateau response at VO2max during a series of pre-determined trials. METHODS: Ten male well-trained athletes (age, 23.0 ± 3.2; height, 183.3 ± 5.5 cm; mass 77.5 ± 11.1 Kg; VO2max 66.5 ± 5.0 ml.kg-1,min-1), but who were VO2max testing naïve and with prior-knowledge of trial number completed four incremental tests to volitional exhaustion, separated by ~72-h for the determination of VO2max and gas exchange threshold. Throughout all trials VO2max was recorded on a breath-by-breath basis using a pre-calibrated metabolic cart, using a plateau criterion of Δ VO2 ≤1.5 ml.kg-1.min-1 over the final 2 consecutive 30 s sampling periods. A significant difference was observed between trial-1 and trial-4 for plateau incidence (p = 0.0285) rising from 20% in trial-1 to a 70% response rate in trial-4. Furthermore a significant difference was observed for VO2dif (difference be-tween criterion value and Δ VO2) in trial-1, 1.02 ± 1.69 ml.kg-1.min-1 (p = 0.038), with non-significant differences observed for all other trials, despite a non-significant difference for VO2max across all trials (p > 0.05). Finally, a significant difference was observed for effort perception (RPE) at volitional exhaustion between trial-1 (17.7 ± 1.3) and trial-4 (19.0 ± 1.4) (p = 0.0052). These data indicate that prior-knowledge of trial number can influence the manifestation of the VO2 plateau in a group of well-trained male athletes, thereby suggesting that a form of effort control is established in order to preserve the finite anaerobic capacity

COVID-19: Social Distancing and Physical Activity in United Kingdom Residents With Visual Impairments

Introduction: The introduction of the COVID-19 lockdown and social distancing policy has the potential to restrict access to physical activity, change exercise behavior, and to increase sedentary behavior. This study was conducted with the support of British Blind Sport and evaluates the effect of the lockdown policy on adults with visual impairments in the United Kingdom (UK). Methods: An online survey based on the World Health Organization’s Global Physical Activity Questionnaire was completed by 73 participants (median age 35–44 years, 59% female) to gain information on how the implementation of the lockdown policy by the UK government has affected physical activity and sedentary behavior in adults that are visually impaired. Paired sample t-tests and Wilcoxon signed rank tests were used to analyze continuous and Likert scale data, respectively. Results: The majority of participants continued to exercise during lockdown, but the nature of this activity altered with a significant change to exercising in a private indoor space (+190% (always), z = −3.871, p < 0.001), and those exercising alone (+118% (always), z = −2.595, p = 0.009). The volume of activity reduced in all cases, between −11% and −52%, with significant changes in duration of vigorous day-to-day activity, moderate day-to-day activity, travel by foot or cycle, and vigorous recreational activity. Sedentary behavior increased on average by 21% ( t(59) = −2.050, p = 0.045), with a greater effect seen in females (+36%, t(35) = −2.525, p = 0.016). Discussion: Reductions in physical activity volume and increases in sedentary behavior are consequences of the UK lockdown for those with visual impairments. The health and well-being implications of these data to this specific population are of particular concern. Implications for Practitioners: Lockdown measures should be designed with consideration of the needs of people with disabilities. Innovative ways to engage these populations in physical activity are strongly encouraged

Physiological and training characteristics of recreational marathon runners

Purpose: The aim of this study was to examine the physical and training characteristics of recreational marathon runners within finish time bandings (2.5–3 h, 3–3.5 h, 3.5–4 h, 4–4.5 h and >4.5 h). Materials and methods: A total of 97 recreational marathon runners (age 42.4 ± 9.9 years; mass 69.2 ± 11.3 kg; stature 172.8 ± 9.1 cm), with a marathon finish time of 229.1 ± 48.7 min, of whom n = 34 were female and n = 63 were male, completed an incremental treadmill test for the determination of lactate threshold (LT1), lactate turn point (LT2) and running economy (RE). Following a 7-min recovery, they completed a test to volitional exhaustion starting at LT2 for the assessment of VO2max. In addition, all participants completed a questionnaire gathering information on their current training regimes exploring weekly distances, training frequencies, types of sessions, longest run in a week, with estimations of training speed, and load and volume derived from these data. Results: Training frequency was shown to be significantly greater for the 2.5–3 h group compared to the 3.5–4 h runners (P 4.5 h group (P = 0.004), while distance per session (km⋅session–1) was significantly greater for the 2.5–3 h group (16.1 ± 4.2) compared to the 3.5–4 h group (15.5 ± 5.2; P = 0.01) and >4.5 h group (10.3 ± 2.6; P = 0.001). Race speed correlated with LT1 (r = 0.791), LT2 (r = 0.721) and distance per session (r = 0.563). Conclusion: The data highlight profound differences for key components of marathon running (VO2max, LT1, LT2, RE and % VO2max) within a group of recreational runners with the discriminating training variables being training frequency and the absolute training speed

Validating the Cambridge Protocol: Reliability of Hip Muscle Strength Measurements Using a Motorized Dynamometer and Electromyography

Background: Muscle weakness is common after injury in athletes and in the presence of hip pathology. It will cause abnormal hip biomechanics and can predict future injury. However, objective measurement of hip muscle strength is difficult to perform accurately and reliably. Therefore, it is challenging to determine when an athlete has returned to preinjury levels of strength. In addition, there is currently no standardized method of obtaining measurements, which prevents the data being compared or shared between research centers. Purpose: The purpose of this study is to comprehensively assess the inter- and intraobserver reliability of our standardized muscle strength measurement protocol. Study Design: Descriptive laboratory study. Level of Evidence: Level 3, inception cohort study. Methods: A total of 16 healthy male volunteers (age = 28.3 ± 7.9 years) were recruited. Those with a previous history of hip injuries or disorders were excluded. These volunteers underwent strength testing according to the Cambridge Protocol on 4 separate occasions, performed by 2 independent assessors. Maximal voluntary contractions, fatigue torque fluctuations, and electromyography measurements were recorded. Intra- and interobserver reliability was assessed using intraclass correlation coefficient (ICC). Results: Good-to-excellent correlation was seen for both intra- and interobserver reliability across almost all hip movements for maximal contractions: ICC ranged 0.78 to 0.93 and 0.78 to 0.96, respectively. The standard error of the mean for all hip movements was also extremely low at 2% to 3%. Conclusion: The Cambridge Protocol is a highly reliable method for objective measurement of hip muscle strength. We recommend future studies use this protocol, or the principles underpinning it, to enable data sharing and comparison across different studies. Clinical Relevance: This is a description and analysis of hip muscle strength measurement. If widely used, it will allow for accurate and objective strength assessment and closer monitoring of hip injuries and pathology

Alternative Metabolic Strategies are Employed by Endurance Runners of Different Body Sizes; Implications for Human Evolution

Objective A suite of adaptations facilitating endurance running (ER) evolved within the hominin lineage. This may have improved our ability to reach scavenging sites before competitors, or to hunt prey over long distances. Running economy (RE) is a key determinant of endurance running performance, and depends largely on the magnitude of force required to support body mass. However, numerous environmental factors influence body mass, thereby significantly affecting RE. This study tested the hypothesis that alternative metabolic strategies may have emerged to enable ER in individuals with larger body mass and poor RE. Methods A cohort of male (n = 25) and female (n = 19) ultra-endurance runners completed submaximal and exhaustive treadmill protocols to determine RE, and V̇O2Max. Results Body mass was positively associated with sub-maximal oxygen consumption at both LT1 (male r=0.66, p<0.001; female LT1 r=0.23, p=0.177) and LT2 (male r=0.59, p=0.001; female r=0.23, p=0.183) and also with V̇O2Max (male r=0.60, p=0.001; female r=0.41, p=0.046). Additionally, sub-maximal oxygen consumption varied positively with V̇O2Max in both male (LT1 r=0.54, p=0.003; LT2 r=0.77, p<0.001) and female athletes (LT1 r=0.88, p<0.001; LT2 r=0.92, p<0.001). Conclusions The results suggest that, while individuals with low mass and good RE can glide economically as they run, larger individuals can compensate for the negative effects their mass has on RE by increasing their capacity to consume oxygen. The elevated energy expenditure of this low-economy high-energy turnover approach to ER may bring costs associated with energy diversion away from other physiological processes, however

The Effects of Non-Contingent Feedback on the Incidence of Plateau at V̇O2max

International audienceThe purpose of this study was to examine the effects of non-contingent feedback in the form of heart rate (HR) on the incidence of plateau at V̇O2max. Ten physically active males (age 24.8 yrs ± 4.2; mass 81.4 ± 9.0 kg; stature 1.80 ± 0.11 m, V̇O2max 53.2 ± 5.8 ml·kg-1.min-1) who were V̇O2max testing naïve but were cognisant as to the heart rate responses to exercise completed four incremental tests to volitional exhaustion, separated by ~72 h for the determination of V̇O2max and gas exchange threshold. The first trial served as a familiarisation with the remaining three being experimental conditions where HR was presented in a screen projection as either the actual response (HR-A) or 10 b·min-1 higher than recorded (HR-H) or 10 b·min-1 lower (HR-L). Throughout all trials V̇O2 was recorded on a breath-by-breath basis with plateau criteria of ≤ 50 ml·min-1. RESULTS: A significant difference was observed for Δ V̇O2 over the final two consecutive 30s sampling periods between HR-A, both HR-L and HR-H (p = 0.049) and for the incidence of plateau response between condition (p = 0.021). An additional significant difference was observed for sub-maximal Δ V̇O2 responses between HR-A and HR-H (p = 0.049) and HR-A and HR-L (p = 0.006). Non-significant differences were observed for all other criteria. These data indicate that when presented with non-contingent feedback in the form of HR, that the perceptually orientated pacing schema becomes disrupted promoting a sparing of the finite anaerobic capacity to compensate for the imbalance between the afferent signal and perception of effort. Key points The manifestation of the plateau at V̇O2max is disrupted (lower incidence rates) when participants are exposed to non-contingent feedback in the form of heart rate. Non-contingent feedback in the form of heart rate does not affect the V̇O2max score or associated cardio-respiratory parameters. Given the association between the V̇O2-plateau and the finite anaerobic capacity it is proposed that non-contingent feedback creates a sparing of this resource due to an imbalance between the perception of effort and the bio-feedback