Participation in ultramarathon events has grown substantially in the past decade. However, poor understanding of the physiological outcomes associated with participation in this sport prevents athletes and clinicians from adequately addressing performance and recovery tactics. The purpose of this review was to summarize developments in the literature in the last 10 years regarding acute and chronic responses to ultramarathon running with a focus on the peripheral vascular system, neuromuscular outcomes, and running mechanics. Evidence suggests that there are acute impairments in large artery compliance especially following the longer ultramarathon distances. However, most literature indicates that chronic vascular impairments are not evident in ultramarathon runners. Both central and peripheral fatigue mechanisms contribute to declines in muscle force production that may last up to several weeks in some muscles following an ultramarathon. Alterations in gait kinematics and skeletal muscle oxidative capacity increase the metabolic cost of running over prolonged running distances (> 4 h). Several factors such as elevation changes and nutritional practices make interpretation of findings challenging. Future studies are needed to better understand the interplay among systems and how external factors contribute to these outcomes to optimize performance and inform recovery strategies in this increasingly popular sport.
This study aimed to compare the effects of ground and treadmill running on energy metabolism and muscle contractile properties, providing a basis for the general public to choose running venues.
Ten male college students (age, 20.10 ± 1.53 years; height, 176.20 ± 5.49 cm; weight, 72.14 ± 8.25 kg; body fat percent, 12.41% ± 4.65%) were recruited in this study. Energy expenditure (EE) was measured using the accelerometer (GT9X) combined with specific estimation equations. Average heart rate (HR) was measured using a heart rate band (Polar). Muscle contractile properties were assessed by measuring muscle displacement (Dm) and contraction velocity (Vc) using tensiomyography (TMG-S1). Blood glucose (Glu) and lactate (Lac) were measured by portable devices (eB-G and Lactate Scout). The running speed was 9 km/h and the duration was 25 min. Two-way ANOVA (protocol × time) was used to analyze the effect of running protocols on energy metabolism and muscle contractile properties.
EE of treadmill running was significantly higher than EE of ground running (protocol main effect, P < 0.001), and HR of treadmill running was significantly higher than that of ground running in the first testing time (protocol simple effect, P = 0.026; protocol × time interaction P = 0.043). The decrease in Dm of the rectus femoris after treadmill running was significantly higher than that of ground running (protocol main effect, P = 0.009). The interaction of different running protocols and testing times on Lac was significant (P = 0.025), but all results of the simple effects analysis were not statistically significant (P > 0.05).
Our study found a difference in energy expenditure between treadmill and ground running at 9 km/h with duration of 25 min. In addition, treadmills are more likely to cause a decrease in muscle displacement distance of the rectus femoris measured after exercise than ground running. Future studies are needed to further investigate whether the differences are induced by internal metabolism or the environmental conditions of running.
Portable devices that accurately detect the composition of expired gases and changes in VO2 open new possibilities in research methodology and accessibility.
The purpose of this study was to compare the oxygen consumption (VO2) measurements of the VO2 Master Pro (VM) to the Cosmed K5 (K5) during walking, jogging, and running in field and lab conditions.
Twelve proficient runners, with a current 10 k pace of ≥ 11.29 km/h, performed 3 matched intervals at 3 different speeds (4.82, 8.05, 11.29 km/h) on a treadmill and on an outdoor track. An airflow test was also performed on both devices by pumping air through the devices using a 3 L syringe timed to a metronome at 15, 25, and 35 beats/min.
The VM did not report walking data for most participants. During treadmill running, there were significant differences in VO2 (47.86 ± 3.94 vs. 29.56 ± 4.15 mL/kg/min), ventilation (Ve) (71 vs. 57 mL/min), and tidal volume (TV) (1.89 vs. 1.56 L) between the K5 and VM respectively (P < 0.05). Outdoor analysis also showed significant differences between devices in VO2, Ve, and TV (P < 0.05). The airflow test showed significant differences between the devices in Ve and TV (P < 0.05).
These results suggest that there are significant discrepancies between the K5 and the VM, likely due to differences in TV measurement.
The aims of this study were to propose an alternative method to assess an optimal performance improvement rate (PIR) that would be used as a tool for coaches and elite athletes willing to reach their personal best, mainly those seeking for national, continental or even world record (WR) in middle-distance events. We further compared the improvement rate of women vs. men of the top-10 ranked athletes in the IAAF running these middle-distance events
The top 10 athletes in the IAAF ranking of 800 m, 1500 m, and 3000 m events for each sex were assessed for their history of race times before achieving their personal record (PR). The difference between PR (‘actual’ season) and the best race time in the last season was defined as the 1st season improvement rate (1-SIR), whereas the average improvement rate in the last and preceding seasons was the multi-season improvement rate (M-SIR). 1-SIR and M-SIR were calculated for each athlete.
There were sex differences in the 1500 m with a large effect size (d = − 0.746) in 1-SIR (P = 0.001) and very large (d = − 2.249) in M-SIR (P = 0.001). Women improved more than men before the PR/WR achievements in the 800 m and 1500 m events (P = 0.001) and had similar improvement rates before performing PR/WR in 3000 m events (P = 0.533).
Women improve more before PR/WR achievement in 800 m and 1500 m races. However, in the 3000 m men and women have similar improvement rates in previous seasons before the PR/WR achievement.
This study aimed to investigate the relationships between vertical jump metrics and phases during a 60 m sprint. The variances in strength qualities between sprinters of different ability levels were also compared.
Eighteen young male elite sprinters (age: 18.1 ± 1.3 years; stature: 1.72 ± 0.07 m; body mass: 66.3 ± 6.2 kg) were assessed for squat (SJ), countermovement (CMJ), drop (DJ), and standing long jumps, a maximal load back-squat, and a 60-m sprint from a block-start. The relationships between sprint performances with all variables were analysed using correlation and multiple regression while discriminative parameters between fast (100 m time: ~ 10.50 s) and slow (~ 11.00 s) sprint groups were assessed using independent t-tests.
Higher associations existed between vertical jumps and longer sprint distances, especially between SJ height and relative peak power with 10 m (r = − 0.47 and − 0.47, respectively), 30 m (− 0.71 and − 0.74), 60 m (− 0.76 and − 0.81), 10–30 m (− 0.80 and − 0.86), and 30–60 m (− 0.78 and − 0.84) sprint distances. Concurrently, variables such as relative maximal-strength, relative SJ parameters (height, peak force, and peak power), relative CMJ peak power, and reactive strength index (DJ from 35 cm height) had significant discriminative ability and correlations (P < 0.05) with sprint distances involving maximal velocity and flying-start. Additionally, a combination of SJ height and relative maximal-strength during back-squat accounted for 75% of the variance in 60 m sprint times.
Relative measures of multiple strength metrics may provide better insight regarding factors that enhance sprint performance. Adequate maximal-strength, high explosive power, and reactive strength seem necessary to improve sprint performance in young male elite sprinters.
High-intensity training (HIT) is known to have deteriorating effects on performance which manifest in various physiological changes such as lowered force production and oxidative capacity. However, the effect of HIT in climbing on finger flexor performance has not been investigated yet. Twenty-one climbers partook in an intervention study with three assessment time points: pre-HIT, post-HIT, and 24-h post-HIT. The HIT involved four five-minute exhaustive climbing tasks. Eight climbers were assigned to a control group. Assessments consisted of three finger flexor tests: maximum voluntary contraction (MVC), sustained contraction (SCT), and intermittent contraction tests (ICT). During the SCT muscle oxygenation (SmO2) metrics were collected via NIRS sensors on the forearm. The HIT had significant deteriorating effects on all force production metrics (MVC − 18%, SCT − 55%, ICT − 59%). Post-24 h showed significant recovery, which was less pronounced for the endurance tests (MVC − 3%, SCT − 16%, ICT − 22%). SmO2 metrics provided similar results for the SCT with medium to large effect sizes. Minimally attainable SmO2 and resting SmO2 both showed moderate negative correlations with pre-HIT force production respectively; r = − 0.41, P = 0.102; r = − 0.361, P = 0.154. A strong association was found between a loss of force production and change in minimally attainable SmO2 (r = − 0.734, P = 0.016). This study presents novel findings on the deteriorating effects of HIT on finger flexor performance and their oxidative capacity. Specifically, the divergent results between strength and endurance tests should be of interest to coaches and athletes when assessing athlete readiness.
The Farmer’s Walk (FW) may supplement resistance training through functional tasks like lifting and carrying weight over various distances. Minimal information exists concerning the intramuscular responses resulting from FW performance, possibly impacting its application in exercise prescription. Therefore, the purpose of the study was to investigate Creatine Kinase (CK) and myoglobin (Mb) responses following the Farmers Walk Condition (FWC) compared to a control protocol (NWC).
Fifteen participants (Mean ± SEM; age: 21.6 ± 0.5 years; height: 172.5 ± 2.4 cm; body weight: 81.8 ± 4.0 kg) completed an initial session to measure body composition, lower body power, and strength. Participants then completed two counter-balanced exercise protocols consisting of a 20-m walk performed within 5 sets of 2 repetitions while either carrying weight (FWC; average wt: 85.15 ± 25.55 kg) or not (NWC) with collection of Visually Perceived Muscle Soreness (VPMS), Ratings of Perceived Exertion (RPE), and blood samples. VPMS, blood samples, and Countermovement Jump (CMJ) height were also collected during recovery from each exercise protocol with significance of P < 0.05.
Significant differences were observed between exercise protocols performed including participant RPE (P < 0.01), CK (P = 0.01), and overall, upper body, and lower body VPMS (P < 0.05) post-FWC. No significant differences were noted for Mb or CMJ height.
Training variables implemented during the FWC may have indirectly minimized muscle damage and neuromuscular inhibitions in performance. Although participants reported mild soreness, the negligible physiological damage suggests the FWC is a safe and appropriate functional movement exercise.
Understanding the femur load environment during daily activity is necessary for the understanding of risk of femoral pain, pain related falls, and femoral fractures, which could help the design of osteogenic exercises or the preventative methods for older adults.
Using the finite element femur analysis, this study was to estimate the femoral strains at 9 cross-sections along the long axis of femur for stair ascent and descent (n = 17; age: 50–65 years). Motion analysis and inverse dynamics were combined with musculoskeletal modelling and optimization, then were used as input to a 3-D femur model to estimate femoral strains. Strains at the hip contact force peaks were calculated.
The compressive and tensile strains during stair descent were greater than ascent for all or most cross-sections, especially for the proximal cross-sections of the femur: stair ascent produced − 324.0 ± 103.8 to − 483.7 ± 191.0 µε compressive strains and descent produced − 608.8 ± 288.4 to 1016.0 ± 444.1 µε; stair ascent produced 336.2 ± 105.4 to 391.8 ± 136.9 µε tensile strains and descent produced 546.9 ± 252.8 to 741.7 ± 333.6 µε.
Strains represent the material deformation effect on the bone due to the sum of all the bone external loads. Using bone strains could help future studies analyze load conditions in a more comprehensive way for other physical activities, which predicts the risk of stress fractures and tests if alternative methods (gait type change) could reduce stress and strain effectively.
Muscle strength and power are important requirements in many sports. The correlation of jumping performance as manifestation of muscle power and squatting one-repetition maximum (1RM) has been shown in several investigations. Correlations with maximum force in a linear isokinetic leg press are still pending. Since different testing devices produce different relationships and rotational isokinetic measurements show conflicting results, further evidence is needed.
We investigated the correlation of isokinetic leg press force at 0.1 m/s and 0.7 m/s with squat 1RM and jumping performance in different vertical jumps.
The results show medium to strong, significant correlations for isokinetic force at 0.1 m/s with squat- and countermovement-jump performance, whereas isokinetic force at 0.7 m/s showed strong, significant correlations for both jumping tests. Drop jump performance (dropping heights: 20, 30, 40, and 50 cm, respectively) reveals weak to medium, significant correlations with isokinetic force at 0.1 m/s and weak, significant correlations with isokinetic force at 0.7 m/s. Squat 1RM displays strong relationships to isokinetic force with greater coefficients regarding higher movement speed in the isokinetic condition.
The maximum strength of the leg extensors displays a basic requirement for vertical jumping with great motion in knee- and hip-joints and should be considered in training programs. For vertical jumps that are mainly generated via ankle motion, maximum strength of knee- and hip-extensors plays an indirect role to guarantee for performance-enhancing mechanisms. Additionally, in strength testing, different manifestations of strength performance should carefully be taken into account.
The majority of previous research evaluating the effects of acute exercise on episodic memory function have focused on explicit memory tasks involving word-list paradigms. For a more real-world application, the present experiment evaluates whether high-intensity acute exercise can improve episodic memory function of incidentally processed information as well as increase one’s ability to remember names associated with faces (face-name paradigm). A two-arm, parallel-group, randomized controlled intervention was employed. Participants (N = 91; Mage = 20 years) were randomized into one of two groups, including an experimental group and a control group. The experimental group exercised for 20 min on a treadmill at a high-intensity (75% of heart rate reserve), while the control group engaged in a seated, time-matched task. Explicit memory was assessed from an intentional processing face-name paradigm in which participants encoded and subsequently recalled names that were paired with faces. Episodic memory for incidentally processed information was evaluated with a computerized program involving spatial–temporal integration. The mean (SD) number of correctly recalled face-name pairs between the exercise and control groups, respectively, for immediate memory were 11.16 (4.4) and 9.79 (4.3), P > 0.05. Results were similar for incidentally processed information, in that there were no differences between the exercise [7.30 (1.7)] and control [7.52 (1.9)] groups, P > 0.05. Overall, we did not observe evidence that high-intensity acute exercise improves episodic memory for incidentally or intentionally processed information.