Subsequent Running Performance Research Articles

Acute Effect of Velocity-Based Resistance Training on Subsequent Endurance Running Performance: Volume and Intensity Relevance

This study aimed to compare the acute effect of four back squat velocity-based training (VBT) protocols in terms of intensity (60% vs. 80% of the one repetition maximum [1RM]) and volume (10% vs. 30% threshold for velocity loss in the set) on the maximal aerobic speed (MAS) estimated from a running track test (RTT) in recreationally trained young adult men and women. Twenty participants (eleven men and nine women) undertook five randomized protocols in separate occasions: (i) RTT alone (control condition); (ii) VBT with 60% 1RM and a 10% velocity loss followed by RTT (VBT60–10 + RTT); (iii) VBT with 60% 1RM and a 30% velocity loss followed by RTT (VBT60–30 + RTT); (iv) VBT with 80% 1RM and 10% velocity loss followed by RTT (VBT80–10 + RTT); (v) VBT with 80% 1RM and 30% velocity loss followed by RTT (VBT80–30 + RTT). All VBT protocols involved three sets with three minutes of rest. The MAS was higher for RTT (control) than VBT60–30 + RTT (p < 0.001; Δ = 3.8%), VBT60–10 + RTT (p = 0.006; Δ = 2.8%), VBT80–10 + RTT (p = 0.008; Δ = 2.7%), and VBT80–30 + RTT (p = 0.019; Δ = 1.9%). No protocol × sex interaction was noted (p = 0.422). Therefore, regardless of sex, MAS is acutely impaired after VBT, especially if the training sets are performed with a low relative load and a high velocity loss threshold.

Impaired pre-competition wellbeing measures can negatively impact running performance in developmental youth female soccer players.

This study aimed to determine the association between pre-competition perceived player wellbeing measures and subsequent relative and peak running performance of developmental youth female soccer players (n = 15, age: 16 ± 1 years). Total distance (TD), high-speed (> 3.5 m/s) (HSRD) and very high-speed (> 5.3 m/s) running (VHSRD) were expressed using 1-, 2- and 5-minute epochs and relative (per minute) calculations. Fatigue, sleep quality, upper and lower-body muscle soreness, stress, and mood wellbeing measures were collected via a self-reported questionnaire (1-5 Likert scale). Menstrual cycle phase was collected via a calendar-based countback method. Results demonstrated that reductions in stress was associated with decreased relative and peak TD in all epochs (p = 0.008-0.040), relative and peak HSRD (p = 0.006-0.039) in 2- and 5-minute epochs as well as VHSRD in 2-minute epochs (p = 0.026). For example, a one-point reduction of 'normal' to 'relaxed' is associated with a decrease of 7 m/min in peak TD for 1-minute epochs. One-point increase in fatigue (e.g., 'normal' to 'more tired than normal') displayed a decrease of 7 m/min peak TD for 2-minute (p = 0.048) and 9 m/min for 5-minute (p = 0.007) rolling epochs. Likewise, one-point increase in lower-body muscle-soreness (e.g., 'normal' to 'increase in soreness/tightness') was associated with a reduction of 6 m/min peak VHSRD for 1-minute epochs (p = 0.034). Results suggest that perceived player wellbeing can influence running performance. However, the magnitude of the change in player wellbeing should be considered in a practical sense.

Effects of whole-body vibration warm-up on subsequent jumping and running performance

The aim of this study was to examine whether acute whole-body vibration, a single bout of drop jumps, or a combination of both may enhance countermovement jump (CMJ) and would affect volitional pace 3 km running performance. Twelve healthy and recreationally active males completed 4 conditions in randomized order: (i) 5 sets of 30 s calf raises on the platform but without vibration; (ii) 5 sets of 30 s calf raises on the vibration platform with 30 s rest intervals between sets; (iii) 5 sets of 6 drop jump with a 30 s rest interval between sets; (iv) 5 sets of 30 s calf raises on the vibration platform followed by 6 drop jumps with a 30 s rest interval between sets. Before, 3-min after, and immediately after a 3 km run each participant performed CMJ. No significant difference between conditions (p = 0.327) for the 3 km time trial was found. Whereas CMJ height and relative peak power were significantly improved in post-3 km run than at baseline (p < 0.001 and p = 0.025) and post-warm-up (p = 0.001 and p = 0.002) in all conditions. The present study indicates that warm-up consisting of either whole-body vibration, drop jumps, or a combination of both failed to acutely improve CMJ and 3 km volitional pace running performance in physically active males. However, the increase in the CMJ performance was noted after the end of the 3 km run, which may indicate that the warm-up protocols used were insufficient to enhance subsequent performance.

The effect of acute manipulation of carbohydrate availability on high intensity running performance, running economy, critical speed, and substrate metabolism in trained Male runners

ABSTRACT Completing selected training sessions with reduced glycogen availability is associated with greater signalling and improved muscle oxidative capacity, although it may impact the overall quality of the session. We examined the effects of low carbohydrate availability on high intensity exercise performance, running economy, critical speed, and substrate metabolism. On two occasions, nine male runners (V̇O2peak 60.3 ± 3.3 mL.kg−1.min−1) completed a glycogen depletion protocol involving 90-min at 75%vV̇O2peak followed by 10 × 1-min at 110% vV̇O2peak. This was followed either by high (HIGH) or low (LOW) carbohydrate intake (>6 g.kg−1.day−1 and <50 g.day−1, respectively) until completion of a performance protocol on day 2 consisting of a series of time-trials (TT) (50m to 3000m) and physiological assessments. There were no differences between LOW and HIGH for any TT distance (mean TT performance times for LOW and HIGH were: 3000m TT 651.7 ± 52.8s and 646.4 ± 52.5s, 1500 m TT 304.0 ± 20.2s and 304.2 ± 22.1s, 400 m TT 67.64 ± 4.2s and 67.3 ± 3.8s, 50 m TT 7.27 ± 0.44s and 7.25 ± 0.45s, respectively, P > 0.05), though some athletes performed better in LOW (n = 5). While fat oxidation in LOW was significantly greater than HIGH (Δ0.32 ± 0.14 g.min−1; P < 0.001 at 14 km.h−1 and Δ0.34 ± 0.12 g.min−1 at 16 km.h−1; P < 0.01), running economy did not differ between trials (P > 0.05). Acute manipulation of carbohydrate availability showed immediate effects on substrate metabolism evidenced by greater fat oxidation without changes in RE. Acute low carbohydrate availability did not affect high intensity running performance across a range of distances. Highlights Acute manipulation of muscle glycogen availability using an exercise and dietary manipulation protocol did not affect subsequent high intensity running performance across a range of running distances. Reduced muscle glycogen resulted in a marked increase in fat oxidation in low glycogen condition but no changes in running economy or critical speed. Individual factors should be considered when prescribing high intensity sessions with restricted carbohydrate availability.

Effects of Post-Activation Performance Enhancement (PAPE) Induced by a Plyometric Protocol on Deceleration Performance

Post-Activation Potentiation (PAP) is a phenomenon which can improve power performance executed after a previous conditioning activity. PAP is usually evoked through heavy resistance or plyometric exercise. It has been suggested to refer to as Postactivation Performance Enhancement (PAPE) when research is field-based on explosive activities. To our best knowledge, no studies have investigated the effects of PAPE on deceleration performance, which is a key factor in sports involving change of directions. Therefore, the aim of this study was to investigate the influence of a plyometric exercise protocol on a subsequent deceleration running performance. University soccer players (n = 18) performed seven deceleration trials and were assessed at baseline and after ~15 s, 2, 4, 8, 12 and 16 min either following a walking control condition (C) or three sets of ten repetitions of alternate-leg bounding (plyometric, P). Results showed no significant differences at any of the trials under the control condition (C) in comparison to the relative baseline. Under the plyometric condition (P), deceleration performance executed two minutes after the plyometric activity resulted in significantly faster results compared to the baseline values (p = 0.042; ES = 0.86, large effect; % of improvement = 4.13 %). The main findings are that plyometric exercise improves a subsequent running deceleration performance, 2 min after its execution. Future investigations should focus on more complex actions such as changes of direction and agility.

Effects of Acacia Honey Drink after Exercise-Induced Dehydration on Selected Physiological Parameters and Subsequent Running Performance

This study examined the effect of honey supplementation on exercise performance and biochemical markers in comparison to plain water and sports drink in the heat. Ten recreational athletes (Age: 22.2 ± 2.0 years, weight: 65.7 ± 5.3 kg; height: 170.4 ± 3.5 cm; VO2max: 51.5 ± 3.7 mL.kg−1.min−1) participated in this study. Participants ran at 70% of their VO2max for 1 h in a pre-load phase (Run-1), followed by a rehydration phase for 2 h and then a 20 min self-paced time trial (Run-2). After Run-1, participants drank either Acacia honey, sports drink or plain water with an amount equivalent to 150% of body weight loss. Subsequently, the participants performed the 20 min self-paced time trial. Acacia honey elicited an improved running time trial performance with a significantly (p&lt;0.05) longer distance ran compared to plain water trial, but it was not different from the sports drink trial. In addition, there was no significant difference in running performance between sports drink and plain water trials. Plasma glucose, insulin and free fatty acids were significantly (p&lt;0.05) higher in H and sports drink compared to the W trial during the rehydration phase. There were no significant differences in body weight changes, oxygen uptake, heart rate, rate of perceived exertion, tympanic temperature, plasma volume changes, plasma cortisol, urine osmolality, volume, and specific gravity among the three trials. Thus, Acacia honey can be recommended to be used as a rehydration drink for individuals who train and compete in the heat.

The influence of warm-up duration on simulated rugby league interchange match performance

ABSTRACT Objective The study was conducted to understand the effects of a short (10 min) and a long (30 min) duration warm-up on subsequent readiness to exercise and movement during simulated rugby league match play. Methods: Using a randomised cross-over design, 13 male rugby players (age: 23.6 ± 4.1 y) completed 10- or 30-min warm-up immediately before 2 × 23 min rugby league movement simulation protocol. Results: Total distance, high- and low speed running and tympanic temperature (ES = 0.56 to 20.8) were all higher in the 30 min warm-up, with differences in relative distance and heart rate unclear (ES = -0.36 to 0.06). Differences in participants’ readiness to exercise after the warm-ups were unclear (ES = 0.25). Differences between trials for movement characteristics (ES = -0.13 to -0.32), RPE (ES = -0.13 to 0.04) and B[La] after the simulation were mostly unclear, with only trivial changes in high-speed running (ES = 0.08) and a lower heart rate (ES = -0.26) between the two playing bouts after the 30 min warm-up trial. Conclusion: Practitioners can use warm-ups between 10 or 30 minutes for rugby league interchange players without any implications for subsequent match running performance.

Ecological validity of self-reported wellness measures to assess pre-training and pre-competition preparedness within elite Gaelic football

The current investigation aimed to examine the ecological validity of self-reported wellness questionnaires, and specifically ‘Readiness to Train’ (RTT) as an indicator of pre-training and pre-competition preparedness within elite Gaelic football players. Thirty-seven (n = 37) elite male Gaelic football players (age 26 ± 4; height 181 ± 15 cm, weight 86 ± 4 kg) were recruited for the current study which took place during the 2017 competition season. Participants were monitored using global positioning system technology (GPS; 10-Hz; STATSports Viper Pod; STATSports; Newry, UK) and a self-reported questionnaire (Metrifit, Health, and Sport technologies, Ireland) to provide measures of internal load (RPE; sRPE) external load (GPS variables) and wellness questionnaire (Likert scale: 1–5 response) response to training loads. Results showed that irrespective of the model that the percentage RTT prior to training or match-play was not associated with and running performance measures. Activity type (p ≤ 0.0001), muscle soreness (p ≤ 0.0001), sleep quality (p ≤ 0.0001), and sleep duration (p ≤ 0.0001) all effected subsequent running performance during training and match-play. Furthermore, post hoc analysis showed that specific GPS variables and accumulated training load across specific time durations impacted RPE and total internal training load. Our results indicate that RTT is a poor measure of pre-training and competition preparedness, with individual sub-scales of wellness more appropriate to measure preparedness within Gaelic football players. Practitioners should pay close attention to fluctuations in sleep quality, sleep duration, and muscle soreness when planning training loads. Also, accumulated training loads impact players running capacity and perception of RPE highlighting the importance of longitudinally planning within the Gaelic football training process.

Effect of cycling shoe cleat position on biomechanical and physiological responses during cycling and subsequent running parts of a simulated Sprint triathlon: a pilot study

Proper cleat adjustment improves cycling performance and prevents knee injuries. Recommendations have included positioning the first metatarsal head above the pedal spindle or slightly forward, but mid-foot cleat positions could be more appropriate in triathlons at constant load for their impact on the subsequent running performance. We evaluated the impact of antero-posterior cleat position on biomechanical and physiological variables during the cycling and running parts of a simulated Sprint triathlon. Seven participants performed two 32-min cycling tests including 8 sets of 3 min 30 s intervals performed at just below the power output at the first ventilatory threshold interspersed with 30 s sprints at &gt; 100% of the maximal aerobic power. The cycling exercises were immediately followed by a maximal running performance of 20 min. The tests were performed with a 5-mm backward (BCP) and a 5-mm forward (FCP) first metatarsal cleat position. The BCP decreased the energetic cost during running (5.9%; p = 0.04; effect size [ES] = 0.92) despite no significant performance change in the cycling or the subsequent running tests. Moreover, the BCP resulted in a lower soleus recruitment during sub-maximal intensity (7.0%; p &lt; 0.05; ES = 1.23) and of the gastrocnemius medialis (25.0%; ES = 1.00; p &lt; 0.05) and tibialis anterior (11.9%; ES = 1.51) during the subsequent running. However, we observed much higher recruitment of the soleus (8.8%; ES = 1.36), vastus lateralis (10.1%; ES = 1.37), biceps femoris (12.0%; ES = 1.45), tibialis anterior (16.4%; ES = 3.35), and overall lower limb (11%; ES = 0.92) during sprints with the BCP. Therefore, the BCP could be more suitable in triathlons by being more economical for subsequent running despite the greater muscle activity during the cycling sprints, which form an important part of the cycling portion of Sprint triathlons.

Effects of Cycling on Subsequent Running Performance, Stride Length, and Muscle Oxygen Saturation in Triathletes.

Running performance is a determinant factor for victory in Sprint and Olympic distance triathlon. Previous cycling may impair running performance in triathlons, so brick training becomes an important part of training. Wearable technology that is used by triathletes can offer several metrics for optimising training in real-time. The aim of this study was to analyse the effect of previous cycling on subsequent running performance in a field test, while using kinematics metrics and SmO2 provided by wearable devices that are potentially used by triathletes. Ten trained triathletes participated in a randomised crossover study, performing two trial sessions that were separated by seven days: the isolated run trial (IRT) and the bike-run trial (BRT). Running kinematics, physiological outcomes, and perceptual parameters were assessed before and after each running test. The running distance was significantly lower in the BRT when compared to the IRT, with a decrease in stride length of 0.1 m (p = 0.00) and higher %SmO2 (p = 0.00) in spite of the maximal intensity of exercise. No effects were reported in vertical oscillation, ground contact time, running cadence, and average heart rate. These findings may only be relevant to ‘moderate level’ triathletes, but not to ‘elite’ ones. Triathletes might monitor their %SmO2 and stride length during brick training and then compare it with isolated running to evaluate performance changes. Using wearable technology (near-infrared spectroscopy, accelerometry) for specific brick training may be a good option for triathletes.

Whole-body cryotherapy (−110 °C) following high-intensity intermittent exercise does not alter hormonal, inflammatory or muscle damage biomarkers in trained males

PurposeThis study examined the acute effects of a single session of Whole-body Cryotherapy (WBC) following severe intermittent running exercise on biomarkers of inflammation, muscle damage and stress. MethodsEndurance-trained males (n = 11) were tested twice using a within-participant, balanced cross-over design that consisted of 5 × 5 min of high-intensity running (HIR) followed by either 3 min of WBC at −110 °C or a passive control condition (CON). Before the HIR and after 60 min of recovery a ramp-test was completed. At seven time points up to 24 hrs post exercise venous blood samples were analyzed for serum levels of interleukin 6 (IL-6), interleukin 10 (IL-10), c-reactive protein (CRP), soluble intercellular adhesion molecule-1 (sICAM-1), myoglobin, cortisol, and testosterone. ResultsHIR induced significant increases in all biomarkers except sICAM-1 in both recovery conditions, respectively. Compared to the CON condition WBC did not attenuate exercise- induced changes in IL-6, IL-10, sICAM-1, myoglobin, cortisol, testosterone or their ratio. Increased levels of cortisol following exercise were negatively correlated with subsequent running performance in both conditions (WBC: r = −0.61, p = 0.04; CON: r = −0.64, p = 0.04). ConclusionThe results of this study suggest that the postulated physiological mechanisms by which WBC is proposed to improve recovery, i.e. reductions in inflammation and muscle damage, may not be accurate.

Wearing compression socks during exercise aids subsequent performance

ObjectivesTo assess the effect of wearing compression socks on immediate and subsequent 5km running time trials, with particular attention to the influences on physiological, perceptual and performance-based parameters. DesignCounter-balanced cross-over experiment. MethodsTwelve male runners (mean±SD 5km run time 19:29±1:18min:s) each completed two experimental sessions. Sessions consisted of a standardised running warm-up, followed by a 5km time trial (TT1), a one hour recovery period, then a repeat of the warm-up and 5km time trial (TT2). One session required the use of sports compression socks during the first warm-up and time trial (COMP), while the other did not (CON). ResultsThe decline in run performance in CON from TT1 to TT2 was moderate and significantly greater than that experienced by runners in COMP (9.6s, d=0.67, p<0.01). No difference was found between experimental conditions for oxygen consumption, blood lactate or calf volume (p=0.61, 0.54, 0.64, respectively). Perceptual measures of muscle soreness, fatigue and recovery were also similar between trials (p=0.56, 1.00 & 0.61, respectively). ConclusionsWearing sports compression socks during high intensity running has a positive impact on subsequent running performance. The underlying mechanism of such performance enhancement remains unclear, but may relate to improved oxygen delivery, reduced muscle oscillation, superior running mechanics and athlete beliefs.

Effect of Compression Socks Worn Between Repeated Maximal Running Bouts.

To determine the effect of wearing compression socks between repeated running bouts on perceptual, physiological, and performance-based parameters. Twelve well-trained male runners (mean ± SD 5-km time 19:24 ± 1:19 [min:s]) recorded their perceptions of the efficacy of compression socks for recovery before completion of 2 experimental sessions. Each session consisted of two 5-km running time trials (TT1 and TT2) on a treadmill, with a 1-h recovery period between. In a randomized crossover design, 1 session required participants to wear compression socks during the recovery period, and no compression socks were worn between TTs in the other session (control). Running performance between TT1 and TT2 for runners wearing compression socks was similar between TTs (mean Δ 5.3 ± 20.7 s, d = 0.07, P = .20), whereas for control runners, performance significantly decreased in the second TT (mean Δ 15.9 ± 13.3 s, d = 0.19, P < .01). When grouped by perception of efficacy for compression socks, participants with strong beliefs (n = 7) experienced improved subsequent running performance with compression socks (mean Δ -3.6 ± 19.2 s, d = 0.05, P = .32) compared with those with neutral or negative perceptions (n = 5; mean Δ 17.9 ± 17.0 s, d = 0.19, P = .04). Cross-sectional area of the calf and muscle soreness were significantly reduced during the recovery period with the use of compression socks (P < .01), whereas ratings of fatigue showed no difference between conditions. Wearing compression socks between repeated running bouts can aid recovery and subsequent performance. Furthermore, subsequent exercise performance may be even further enhanced when athletes believe in the efficacy of compression socks to assist in recovery between exercise bouts.

Effect of deceptively aggressive bike pacing on sprint-distance triathlon performance

Introduction : Whilst aggressive bike pacing has been found to impair subsequent run performance during triathlon, this strategy appears to enhance total cycle-run time over the sprint-distance format (Suriano & Bishop, 2010). As such, cycling at the highest sustainable intensity (i.e. isolated TT power output) is suggested as the best strategy to optimise overall performance time in the event. However, it is unclear how an athlete’s expectations, beliefs and perceptions influence the effectiveness of such pacing during multi-modal events, such as triathlon. Taylor & Smith (2013) have suggested that practically meaningful changes in triathlon running may result from deceptive pace manipulation, equivalent to the smallest worthwhile change in performance. With this in mind, deceptively aggressive bike pacing may enable triathletes to maximise their sustainable intensity in this discipline, without the impairments in run performance typically associated with this strategy. However, this is yet to be confirmed by experimental evidence. This study therefore examined the effects of deceptively aggressive bike pacing on sprint- distance triathlon performance. Methods : Having been misinformed that they would be taking part in a reliability and validity study, ten non-elite, competitive male triathletes (mean ± SD: age 36.8 ± 8.9 yrs, mass 76.3 ± 7.2 kg and V, I‡ O 2max 54.3 ± 5.7 ml · kg - 1 · min -1 ) completed eight testing sessions (Figure 1). The first four trials served as familiarisation, after which all athletes completed an isolated 500 kJ (~20 km) cycling time-trial (TT) to establish their maximum sustainable intensity over this distance. Each athlete then completed three separate simulated sprint-distance triathlons (0.75 km swim, 500 kJ bike, 5 km run), the first of which established ‘baseline’ (i.e. personal best) simulated triathlon performance (BL). During the remaining two triathlon trials athletes maintained a cycling power output that was 5% greater than that achieved during BL, before completing the run in as short a time as possible (against an on-screen avatar of BL run performance). However, participants were correctly informed of this aggressive cycling strategy before and during only one of the two trials (Hon). Prior to the alternate trial (Dec), participants were misinformed that their mean cycling power output would equal that of BL, with on-screen feedback manipulated so as to display power output 5% below its true value. Results : Mean performance times for TT and simulated triathlon trials are detailed in Table 1. Although these values suggest a trend for faster run performance during Dec, compared to both BL and Hon, this was only statistically significant versus BL ( p < .05). Similarly, whilst there was a non-significant trend for overall triathlon time to be shorter during Dec than Hon (by ~17 sec), the only statistically significant differences were between each of these trials and BL, which was between 2-3% slower overall than both Dec and Hon. Magnitude-based inferences (Table 2) suggest cycling time and power output were almost certainly better during TT, Dec and Hon, in comparison to BL. Whilst Dec and Hon cycling performances were probably worse compared to that of TT, there were almost certainly no differences between the Dec and Hon cycling. Interestingly, whilst any difference appeared of trivial practical importance, it was more likely that Hon running was meaningfully slower, than faster, compared to BL (i.e. 28:57:15% likelihood of Hon being slower, no different, or faster than BL). On the other hand, Dec running was probably faster than both BL and Hon. In terms of overall triathlon performance, there was almost certainly no difference between Dec and Hon, although both were almost certainly faster compared to BL. Conclusion : An athlete’s expectations, beliefs and perceptions regarding aggressive cycle pacing appear to play an important role in optimising subsequent run and overall performance during sprint-distance triathlon. Future studies should further examine how pacing beliefs and expectations influence performance across multi-modal (i.e. triathlon) or multi-stage (i.e. Tour de France) sporting competitions. In particular, more research is needed so as to better understand the importance of multiple perceptual responses (e.g. RPE and affect) to pacing decisions during successive modes of self-paced exercise.

Effects of Post-Exercise Honey Drink Ingestion on Blood Glucose and Subsequent Running Performance in the Heat

Background:Glycogen depletion and hypoglycemia have been associated with fatigue and decrement of performance during prolonged exerciseObjectives:This study investigated the effectiveness of Acacia honey drink as a post-exercise recovery aid on glucose metabolism and subsequent running performance in the heat.Patients and Methods:Ten subjects participated in this randomized cross-over study. All subjects performed 2 trials. In each trial, all subjects went through a glycogen depletion phase (Run-1), 2-hour rehydration phase and time trial running phase (Run-2). In Run-1, subjects were required to run on a treadmill at 65% VO2max in the heat (31°C, 70% relative humidity) for 60 min. During 2-hour rehydration phase, subjects drank either plain water (PW) or honey drink (HD) with amount equivalent to 150% of body weight loss in 3 boluses (60%, 50% and 40% subsequently) at 0, 30 and 60 min. In Run-2, the longest distance covered in 20 min was recorded for determining running performance. Two-way repeated measured ANOVA and paired t-test were used for analysis.Results:Running distance in Run-2 covered by the subjects in the honey drink HD trial (3420 ± 350 m) was significantly (P < 0.01) longer compared to plain water PW trial (3120 ± 340 m). In general, plasma glucose, serum insulin and osmolality were significantly (P < 0.05) higher in HD compared to PW during the rehydration phase and Run-2.Conclusions:These findings indicate that rehydration with honey drink improves running performance and glucose metabolism compared to plain water in the heat. Thus, honey drink can be recommended for rehydration purpose for athletes who compete in the heat.

Effects of Post-Exercise Honey Drink Ingestion on Blood Glucose and Subsequent Running Performance in The Heat

Background: Glycogen depletion and hypoglycemia have been associated with fatigue and decrement of performance during prolonged exercise Objectives: This study investigated the effectiveness of Acacia honey drink as a post-exercise recovery aid on glucose metabolism and subsequent running performance in the heat. Patients and Methods: Ten subjects participated in this randomized cross-over study. All subjects performed 2 trials. In each trial, all subjects went through a glycogen depletion phase (Run-1), 2-hour rehydration phase and time trial running phase (Run-2). In Run-1, subjects were required to run on a treadmill at 65% VO2max in the heat (31°C, 70% relative humidity) for 60 min. During 2-hour rehydration phase, subjects drank either plain water (PW) or honey drink (HD) with amount equivalent to 150% of body weight loss in 3 boluses (60%, 50% and 40% subsequently) at 0, 30 and 60 min. In Run-2, the longest distance covered in 20 min was recorded for determining running performance. Two-way repeated measured ANOVA and paired t-test were used for analysis. Results: Running distance in Run-2 covered by the subjects in the honey drink HD trial (3420 ± 350 m) was significantly (P < 0.01) longer compared to plain water PW trial (3120 ± 340 m). In general, plasma glucose, serum insulin and osmolality were significantly (P < 0.05) higher in HD compared to PW during the rehydration phase and Run-2. Conclusions: These findings indicate that rehydration with honey drink improves running performance and glucose metabolism compared to plain water in the heat. Thus, honey drink can be recommended for rehydration purpose for athletes who compete in the heat.

Match running performance during fixture congestion in elite soccer: research issues and future directions.

It has been proposed that match congestion in elite soccer results in residual fatigue and underperformance in ensuing competition due to insufficient recovery time. In this article, matters relating to match congestion and running performance in elite soccer competition are discussed. We suggest a need to determine the extent to which elite players are, in reality, exposed to periods of match congestion and hence to potential declines in performance. Despite evidence of exercise-induced muscle damage combined with a decline in physical performance up to 72 h post-match, research using time-motion analyses suggests that running performance represented by distances covered is unaffected over periods of match congestion. We recommend analysis of alternative movement variables including accelerations, decelerations and turns that are taxing metabolically and contribute greatly to muscle damage. Moreover, a holistic approach combining subjective ratings with biochemical, hormonal and immunological responses to exercise would be pertinent, especially in players frequently exposed to match congestion. Contemporary practitioners typically implement various post-match recovery treatments during dense schedules in an attempt to accelerate recovery and ensure that subsequent running performance is not unduly affected. However, empirical evidence to support their efficacy in maintaining running performance is lacking and we recommend controlled intervention studies using match simulations in an attempt to verify their effectiveness. These points are critically addressed using findings from the current scientific literature, while gaps in the current body of knowledge and future directions for research are highlighted.

Day 2. Posters – Sport and Performance

Research investigating the most effective warm-up intensity for subsequent running performance is somewhat varied. When compared to a low-intensity warm-up, Ingham et al. (2013, International Journal of Sports Physiology and Performance, 8, 77–83) found that a high-intensity warm-up significantly improved 800-m running performance in trained runners, whereas Wittekind and Beneke (2008, Journal of Science and Medicine in Sport, 12, 480–484) found that a high-intensity warm-up did not improve run time to exhaustion. The aim of this study was to assess whether a high-intensity warm-up results in a quicker 5-km running time compared to a low-intensity or no warm-up. Eight male recreational competitive runners (23.3 ± 3.6 years, 73 ± 6.4 kg, 178 ± 4.4 cm) completed a timed 5-km treadmill run after completing three warm-up protocols in randomised order, including control condition (C) (no warm-up), a low-intensity (LI) warm-up (5-min self-paced jogging), and a high-intensity (HI) warm-up (5-min self-paced jogging plus four 15-s sprints). Heart rate, ratings of perceived exertion (RPE) and running speed were measured after each kilometre. Blood lactate was measured after each warm-up protocol and upon completing 5-km performances. Ethical approval was granted by the local ethics committee. There was no significant difference (ANOVA: P = 0.80) in 5-km times between trials (HI: 22:13 ± 3:33; LI: 21:54 ± 3:30; C: 22:09 ± 3:20 min) though HI ran the slowest 5 km; running speed was not significantly different after each kilometre, although HI had the highest running speed after 1 km (HI: 14.7 ± 2.7; LI: 14.4 ± 2.3; C: 14 ± 2.4 km · h−1) and slowest at 5 km. Blood lactate concentrations were significantly different (P = 0.02) post warm-up between trials (HI: 3.7 ± 1.1; LI: 2.6 ± 0.7; C: 1 ± 0.1 mmol · l−1), but not significantly different (P = 0.42) after completing 5 km (HI: 6.5 ± 0.9; LI: 6.2 ± 0.9; C: 6.3 ± 0.7 mmol · l−1). Heart rate was similar at each kilometre (P > 0.05); RPE was highest for HI at each kilometre but was only significantly higher (Wilcoxon: P = 0.03; effect size 0.513) at 1 km for HI (14.4 ± 1.1) compared to LI (13.2 ± 0.9). The findings of the study indicate that a high-intensity warm-up does not benefit running performance, similar to findings previously reported (e.g. Wittekind and Beneke, 2008). It is possible that HI resulted in participants starting the 5-km run at too fast a pace coinciding with elevated RPE; this pace could not be maintained and was detrimental to pace later in the run.

The Effects of Elapsed Time After Warm-Up on Subsequent Exercise Performance in a Cold Environment

Athletes often compete in cold environments and may face delays because of weather or race logistics between performance of a warm-up and the start of the race. This study sought to determine, (a) whether a delay after warm-up affects subsequent time trial (TT) performance and (b) if exposure to a cold environment has an additive effect. We hypothesized that after a warm-up, 30 minutes of rest in a cold environment would negatively affect subsequent rowing and running performance. In a temperate (temp; 24° C) or cold (cold; 5° C) environment, 5 rowers (33 ± 10 years; 83 ± 12 kg) and 5 runners (23 ± 2 years; 65 ± 8 kg) performed a 15-minute standardized warm-up followed by a 5- or 30-minute rest and then performed a 2-km rowing or 2.4 km running TT. The 5-minute rest following warm-up in the temperate environment (5Temp) served as the control trial to which the other experimental trials (5Cold; 30Temp; and 30Cold) were compared. Heart rate, lactate, and esophageal (Tes) and skin (Tsk) temperatures were measured throughout. Postrest and post-TT, Tes, and Tsk were lowest in the 30Cold trials. The greatest decrement in TT performance vs. 5Temp occurred in 30Cold (-4.0%; difference of 20 seconds). This difference is considered to have practical importance, as it was greater than the reported day-to-day variation for events of this type. We conclude that longer elapsed time following warm-up, combined with cold air exposure, results in potentially important reductions in exercise performance. Athletes should consider the appropriate timing of warm-up. In addition, performance may be preserved by maintaining skin and core temperatures following a warm-up, via clothing or other means.

Effect of Warm-Up on Intermittent Sprint Performance

We aimed to investigate the effects of different warm-up (WUP) intensities on 10 min of subsequent intermittent-sprint running performance. Eleven male, team-sport players performed four trials in a randomized, cross-over design, consisting of an intermittent-sprint protocol (15 × 20-m sprints) that followed either no-WUP or one of three 10-min WUP trials that varied in intensity. Warm-up intensities were performed at either (1) half the difference between anaerobic threshold (AT) and lactate threshold (LT) [(AT-LT)/2] below the LT = WUP 1; (2) midway between LT and AT level = WUP 2; (3) [(AT-LT)/2] above AT = WUP 3. Sprint times were fastest following WUP 3, compared with all other trials, for sprints 1–9 and 14, as well as for total accumulated sprints, with these results supported by moderate to large effect size (ES; range: d = −0.50 to −1.06) and “possible” to “almost certain” benefits. Warm-up 3 resulted in faster intermittent-sprint running performance compared with lower intensity WUPs and no WUP for the first 6 min of sprinting, with accumulated sprints for the entire 10 min protocol also being faster after WUP 3. This information may be pertinent to coaches of team-sport games with respect to player substitutions.