Does Anaerobic Speed Reserve Influence Post-Activation Performance Enhancement in Endurance Runners?

We investigated the influence of anaerobic speed reserve (ASR) on post-activation performance enhancement (PAPE). Twenty-two endurance runners and triathletes were evaluated for maximum sprinting speed (MSS) and countermovement jump (CMJ) before (non-fatigued) and after (fatigued) an incremental running test. They were allocated in LASR (low-ASR) and HASR (high-ASR) groups for comparisons between conditions. HASR showed greater CMJ and MSS (both p<0.005) performances, with enhanced CMJ in fatigued condition (p=0.008). Significant correlations were found between ASR, CMJ and MSS in both conditions (p≤0.01) for the entire sample, and between ∆CMJ and ∆MSS (p=0.001) in LASR. Our results show that ASR profile influences PAPE.

Effects of a 48-Day Home Quarantine during the Covid-19 Pandemic on the First Outdoor Running Session among Recreational Runners in Spain.

COVID-19-induced quarantine may lead to deleterious effects on health status as well as to impaired performance and increased injury risk when re-starting training after lockdown. We investigated the physical activity (PA) habits of recreational runners in Spain during a 48-day home quarantine during the COVID-19 pandemic and the characteristics of the first outdoor running session after confinement. A cross-sectional study, including a self-reported running questionnaire completed after the first outdoor running session after quarantine, was performed. Three hundred recreational runners (74% males; 60% 18-40 years old; most typical running experience >3 years, 10-30 km weekly running distance distributed in 3-4 sessions) were considered for analysis. Advanced runners ran, at least, 4 days/week and participated in running events. They performed significantly longer and more non-supervised weekly training sessions during confinement (p < 0.01 for both) than novice and amateur runners. Most runners performed their first outdoor running session on asphalt (65.3%) and ran 5 to 10 km (61%) at a pace above 5 min/km (60%), reporting no pain before (77%), during (64%), and 24 h after (76%) the session. Advanced runners performed a significantly longer running session, at a higher pace, and covered a greater distance (p < 0.01 for all) than novice and amateur runners, while enjoyment and motivation tended to be significantly higher when runners' level increased (p < 0.05). Higher training levels prior to and during confinement may lower the collateral effects (e.g., detraining, injury risk) of home quarantine when runners return to previous PA levels.

Does Concurrent Training Intensity Distribution Matter?

Varela-Sanz, A, Tuimil, JL, Abreu, L, and Boullosa, DA. Does concurrent training intensity distribution matter? J Strength Cond Res 31(1): 181-195, 2017-Previous research has demonstrated the influence of intensity distribution on endurance training adaptations. However, no study has addressed the influence of intensity distribution on the effectiveness of concurrent training (CT). The main objective of this study was to compare the effects of 2 CT programs with different training intensity distribution and externally equated loads on physical fitness. Thirty-one sport science students volunteered and were evaluated for resting heart rate variability (HRV), countermovement jump, bench press, half squat, and maximum aerobic speed (MAS). All were randomly distributed into either a traditional-based training group (TT; n = 11; 65-75% of MAS, combined with 10-12 repetition maximum [RM]), polarized training group (PT; n = 10; 35-40% and 120% of MAS, combined with 5RM and 15RM), or control group (CG; n = 10). After 8 weeks of training (3 daysweek), TT and PT exhibited similar improvements in MAS, bench press, and half squat performances. No differences were observed between TT and PT groups for perceived loads. There were no changes in HRV for any group, although TT exhibited a reduction in resting heart rate. Compared with other groups, the PT group maintained jump capacity with an increment in body mass and body mass index without changes in body fatness. In conclusion, PT induced similar improvements in physical fitness of physically active individuals when compared with TT. However, PT produced a lower interference for jumping capacity despite an increment in body mass, whereas TT induced greater bradycardia. Extended studies with different intensity distributions should be conducted to better determine the dose-response of CT in various populations.

Verification criteria for the determination of Vo2 MAX in the field.

The purpose of this study was to evaluate if a verification test (VT) performed in the field offers more confident results than do traditional criteria in the determination of maximal oxygen uptake ((Equation is included in full-text article.)). Twelve amateur runners (age, 36.6 ± 6.6 years) performed a maximal graded field test and after 15 minutes of passive recovery a supramaximal test to exhaustion at 105% of their velocity associated with (Equation is included in full-text article.)(v(Equation is included in full-text article.)). Traditional criteria and 2 different verification criteria were evaluated. Verification criteria were (a) maximal oxygen uptake achieved in the VT ((Equation is included in full-text article.)) must be ≤5% higher than (Equation is included in full-text article.), and (b) no significant differences of means between tests. All participants met the first verification criterion although significant differences were found between (Equation is included in full-text article.)and (Equation is included in full-text article.)(59.4 ± 5.1 vs. 56.2 ± 4.7 ml·kg·min, p < 0.01). The criteria for the plateau, peak heart rate (HRpeak), maximum respiratory exchange ratio (RERmax), and maximum blood lactate concentration ([La]max) were satisfied by 75, 66, 92, and 66 of the participants, respectively. Kappa coefficients gave a significant and substantial agreement beyond chance between traditional criteria (p < 0.001). Despite the substantial agreement, traditional criteria induced the rejection of participants that might have achieved a true (Equation is included in full-text article.)with HRpeak and [La]max being the more stringent criteria for amateur runners. A verification protocol in the field using the criterion based on individual analysis is recommended.

Effect of equated continuous and interval running programs on endurance performance and jump capacity.

We evaluated the effect of 2 different interval and continuous training programs on the maximal aerobic speed (MAS), time limit at MAS (T(lim)), and on the countermovement jump (CMJ). Twenty-two physically active men were randomly distributed in an interval training group (ITG), continuous training group (CTG), and control group. The CTG and ITG performed 2 different training programs (65-70 and 90-100% of the MAS for CTG and ITG, respectively) that consisted of 3 sessions per week during a period of 8 weeks with an identical external workload (% MAS × duration in minutes). The MAS, the T(lim) and the CMJ were recorded before and after the running training programs. The data analysis showed a significant and similar improvement (p < 0.01) of the MAS for both the ITG (5.8%) and CTG (8.3%). The T(lim) and CMJ did not change significantly for either group after the training period. Our results indicate that 8 weeks of continuous or interval running programs with externally equated load led to similar improvements in the MAS without changing T(lim) and CMJ performance in moderately trained nonrunners.

Concurrent fatigue and potentiation in endurance athletes.

PURPOSE: Countermovement jump (CMJ) and maximum running speed over a distance of 20 m were evaluated for examination of the concurrent fatigue and postactivation potentiation (PAP) in endurance athletes after an incremental field running test. METHODS: Twenty-two endurance athletes performed two attempts of CMJ on a force plate and maximum running speed test before and following the Université de Montréal Track Test (UMTT). RESULTS: The results showed an improvement in CMJ height (3.6%) after UMTT that correlated with the increment in peak power (3.4%), with a concurrent peak force loss (-10.8%) that correlated with peak power enhancement. The athletes maintained their 20 m sprint performance after exhaustion. Cluster analysis reinforced the association between CMJ and peak power increments in responders with a reported correlation between peak power and sprint performance increments (r = .623; P = .041); nonresponders showed an impairment of peak force, vertical stiffness, and a higher vertical displacement of the center of mass during the countermovement that correlated with lactate concentration (r = -0.717; P = .02). CONCLUSIONS: It can be suggested that PAP could counteract the peak force loss after exhaustion, allowing the enhancement of CMJ performance and the maintenance of sprint ability in endurance athletes after the UMTT. From these results, the evaluation of CMJ after incremental running tests for the assessment of muscular adaptations in endurance athletes can be recommended.

Postactivation potentiation in distance runners after two different field running protocols.

The purpose of this study was to compare jumping capacity after performing the "Université de Montréal Track Test" (UMTT) and the time limit (Tlim) at maximal aerobic speed. At the end of the competitive season, 12 well-trained male endurance runners performed the UMTT and Tlim tests on 2 different days separated by 48 hours to 7 days. Countermovement jump (CMJ) performance was assessed before and at the second and seventh minute after the 2 running protocols. An enhanced CMJ was observed at the second minute of recovery after UMTT and Tlim (p = 0.000; p = 0.015, respectively) and remained elevated only after the UMTT (p = 0.000). No significant correlations were found between jump and endurance field running performance. It is concluded that the postactivation potentiation profile after fatiguing running exercises in distance runners is protocol dependent with the mechanism yet to be determined.

Parasympathetic modulation and running performance in distance runners.

This study examined the relationships between basal heart rate (BHR) and heart rate recovery (HRR), parasympathetic modulation parameters, with running performance in distance runners. It was hypothesized that greater parasympathetic modulation would be significantly associated with greater running performance. Twelve well-trained endurance runners (23.2 +/- 3.3 years; 175.6 +/- 5.8 cm; 65.2 +/- 6.7 kg) performed the Université de Montréal Track Test (UMTT) until volitional exhaustion (total final time, TUMTT), with the highest completed stage recorded as the maximal aerobic speed (MAS). More than 48 hours afterwards, participants ran at the MAS until volitional exhaustion, with maximal running time (Tlim) recorded. Maximum heart rate was significantly greater for the UMTT compared with Tlim (p = 0.004). Significant correlations were exhibited between MAS and BHR (r = -0.845, p = 0.001); mean drop in heart rate at the first minute of recovery after the UMTT (r = 0.617, p = 0.033) and Tlim (r = 0.787, p = 0.002); and mean drop in heart rate at the second minute of recovery after the UMTT (r = 0.630, p = 0.028). These results support previous reports that endurance training results in greater running performance and greater parasympathetic modulation before and after exercise. We suggest that coaches consider HRR and BHR for the monitoring of training for endurance performance.