Intensity Running Research Articles

Is Running Power a Useful Metric? Quantifying Training Intensity and Aerobic Fitness Using Stryd Running Power Near the Maximal Lactate Steady State.

We sought to determine the utility of Stryd, a commercially available inertial measurement unit, to quantify running intensity and aerobic fitness. Fifteen (eight male, seven female) runners (age = 30.2 [4.3] years; V·O2max = 54.5 [6.5] ml·kg-1·min-1) performed moderate- and heavy-intensity step transitions, an incremental exercise test, and constant-speed running trials to establish the maximal lactate steady state (MLSS). Stryd running power stability, sensitivity, and reliability were evaluated near the MLSS. Stryd running power was also compared to running speed, V·O2, and metabolic power measures to estimate running mechanical efficiency (EFF) and to determine the efficacy of using Stryd to delineate exercise intensities, quantify aerobic fitness, and estimate running economy (RE). Stryd running power was strongly associated with V·O2 (R2 = 0.84; p < 0.001) and running speed at the MLSS (R2 = 0.91; p < 0.001). Stryd running power measures were strongly correlated with RE at the MLSS when combined with metabolic data (R2 = 0.79; p < 0.001) but not in isolation from the metabolic data (R2 = 0.08; p = 0.313). Measures of running EFF near the MLSS were not different across intensities (~21%; p > 0.05). In conclusion, although Stryd could not quantify RE in isolation, it provided a stable, sensitive, and reliable metric that can estimate aerobic fitness, delineate exercise intensities, and approximate the metabolic requirements of running near the MLSS.

Different Aspects of Physical Load in Small-Sided Field Hockey Games.

Wilmes, E, de Ruiter, CJ, van Leeuwen, RR, Banning, LF, van der Laan, D, and Savelsbergh, GJP. Different aspects of physical load in small-sided field hockey games. J Strength Cond Res 38(2): e56-e61, 2024-Running volumes and acceleration/deceleration load are known to vary with different formats of small-sided games (SSGs) in field hockey. However, little is known about other aspects of the physical load. Therefore, the aim of this study was to gain a more thorough understanding of the total physical load in field hockey SSGs. To that end, 2 different SSGs (small: 5 vs. 5, ∼100 m 2 per player; large: 9 vs. 9, ∼200 m 2 per player) were performed by 16 female elite field hockey athletes. A range of external physical load metrics was obtained using a global navigational satellite system and 3 wearable inertial measurement units on the thighs and pelvis. These metrics included distances covered in different velocity ranges (walk, jog, run, and sprint), mean absolute acceleration/deceleration, Hip Load, and time spent in several physically demanding body postures. The effects of SSG format on these external physical load metrics were assessed using linear mixed models ( p < 0.05). Running volumes in various speed ranges were higher for the large SSG. By contrast, mean absolute acceleration/deceleration and time spent in several demanding body postures were higher for the small SSG. This study shows that changing the SSG format affects different aspects of physical load differently.

The Effects of a Supramaximal Intermittent Training Program on Aerobic and Anaerobic Running Measures in Junior Male Soccer Players.

This study investigated the effectiveness of supplementing regular preseason soccer training with a supramaximal intermittent shuttle-run training (ISRT) model prescribed from Carminatti's Test peak speed (PST-CAR) in aerobic performance-related indices and sprinting speed in male junior soccer players. Twenty-three national-level soccer players (mean ± SD; age 18.07 ± 0.9 y, body height 1.76 ± 0.65 m, body mass 71.9 ± 8.7 kg) were assigned to either an experimental group (EG; n = 13) performing ISRT + soccer training or a control group (CG; n = 10) that followed regular preseason soccer training alone. The following tests were applied before and after the eight-week training intervention: (i) incremental treadmill tests (VO2max and lactate minimum speed - LMS); (ii) linear 30-m sprint test and Carminatti's Test (PST-CAR). Results indicated larger gains for the EG in LMS (Δ = 9.53% vs. 2.82%) and PST-CAR (Δ = 5.50% vs. 2.10%) than in the CG. Furthermore, changes in VO2max produced higher effect size (d) values for the EG (Δ = 6.67%; d = 0.59) than the CG (Δ = 1.88%; d = 0.18). Both groups improved (p = 0.002) their flying 20-m sprint speed (EG: Δ = 1.01%; CG: Δ = 1.56%). However, small decreases were observed for 10-m sprint speed in the CG (Δ = -2.19%; d = -0.44), while only trivial changes were noticed for the EG (Δ = -0.50%; d = -0.16). Our data support that additional supramaximal ISRT is an effective training stimulus to enhance aerobic performance-related indices and promote small improvements in maximal running speed without impairing the soccer players' acceleration capacity. This study also shows that PST-CAR can be useful for individualizing running intensity in supramaximal ISRT modes.

Time Course Effects of Different Intensities of Running Exercise on Cognitive and Motor Performances in Individuals With Intellectual Disability.

This study explored the acute effects of different running intensities on cognitive and motor performances in individuals with intellectual disability (ID). An ID group (age, M = 15.25years, SD = 2.76) and a control group without ID (age, M = 15.11years, SD = 1.54) performed visual simple and choice reaction times, auditory simple reaction time, and finger tapping tests before and after running at low or moderate intensity (30% and 60% of heart rate reserve [HRR], respectively). Visual simple reaction time values decreased (p < .001) after both intensities at all time points with higher (p = .007) extend after the 60% HRR intensity for both groups. After both intensities, the VCRT decreased (p < .001) in the ID group at all time points compared with preexercise (Pre-EX) while, in the control group, these values decreased (p < .001) only immediately (IM-EX) and after 10min (Post-10) of exercise cessation. Compared withs Pre-EX, in the ID group, the auditory simple reaction time values decreased (p < .001) at all time points after the 30% HHR intensity whereas, after the 60% HRR, these values decreased only at IM-EX (p < .001), Post-10 (p = .001) and Post-20 (p < .001). In the control group, auditory simple reaction time values decreased (p = .002) only after the 30% HRR intensity at IM-EX. The finger tapping test increased at IM-EX (p < .001) and at Post-20 (p = .001) compared to Pre-EX in both groups only after the 30% HHR intensity and for the dominant hand. The effect of physical exercise on cognitive performances in individuals with ID seems to depend on the cognitive test type as well as the exercise intensity.

The impact of progressively increasing run intensity on the proportion and frequency of positive cardio-respiratory fitness responders

The impact of progressively increasing run intensity on the proportion and frequency of positive cardio-respiratory fitness responders

Kinetic, Physiological and Fatigue Level Differences Depending on the Menstrual Cycle Phase and Running Intensity

Background: Depending on the phase of the menstrual cycle an athlete is in, some kinetic, physiological, and fatigue variables will show differences. The aim of this study is to analyze whether there are changes in these variables over the course of the menstrual cycle. Methods: Eight regularly practicing women runners and triathletes performed a maximal treadmill test and a submaximal test (6′ stages at 50%, 60%, and 80% of maximal aerobic speed) in each of the phases of the menstrual cycle: bleeding phase (day 2.4 ± 0.7), follicular phase (day 10.4 ± 2.2), and luteal phase (day 21.8 ± 2.1). Running dynamics were measured (using RunScribe) at the end of each test, as were lactate concentration, heart rate, and fatigue (evaluated on a scale of 0–5). Results: Higher shock (G) values were recorded in the bleeding phase (η2 = 0.27) and higher vertical spring stiffness (kN/m) was recorded in the follicular phase (η2 = 0.25). The phase of the menstrual cycle had a significant effect on average and peak heart rate, which was significantly higher in the follicular phase (η2 = 0.45 and η2 = 0.48, respectively). Conclusions: Higher vertical spring stiffness was observed in the follicular phase, in addition to higher peak and average heart rate.

Effects of different running intensities on the micro-level failure strain of rat femoral cortical bone structures: a finite element investigation

BackgroundRunning with the appropriate intensity may produce a positive influence on the mechanical properties of cortical bone structure. However, few studies have discussed the effects of different running intensities on the mechanical properties at different levels, especially at the micro-level, because the micromechanical parameters are difficult to measure experimentally.MethodsAn approach that combines finite element analysis and experimental data was proposed to predict a micromechanical parameter in the rat femoral cortical bone structure, namely, the micro-level failure strain. Based on the previous three-point bending experimental information, fracture simulations were performed on the femur finite element models to predict their failure process under the same bending load, and the micro-level failure strains in tension and compression of these models were back-calculated by fitting the experimental load–displacement curves. Then, the effects of different running intensities on the micro-level failure strain of rat femoral cortical bone structure were investigated.ResultsThe micro-level failure strains of the cortical bone structures expressed statistical variations under different running intensities, which indicated that different mechanical stimuli of running had significant influences on the micromechanical properties. The greatest failure strain occurred in the cortical bone structure under low-intensity running, and the lowest failure strain occurred in the structure under high-intensity running.ConclusionsModerate and low-intensity running were effective in enhancing the micromechanical properties, whereas high-intensity running led to the weakening of the micromechanical properties of cortical bone. Based on these, the changing trends in the micromechanical properties were exhibited, and the effects of different running intensities on the fracture performance of rat cortical bone structures could be discussed in combination with the known mechanical parameters at the macro- and nano-levels, which provided the theoretical basis for reducing fracture incidence through running exercise.

Running-Related Overuse Injuries and Their Relationship with Run and Resistance Training Characteristics in Adult Recreational Runners: A Cross-Sectional Study.

This study aimed to characterize running-related injuries (RRIs), explore their relationship with run and resistance training (RT) parameters, and identify perceived prevention measures among adult recreational runners. An anonymous online survey was designed and distributed via social media and email. Data were analyzed with chi-square, t-test, or analysis of variance (ANOVA), with significance accepted at p ≤ 0.05. Data from 616 participants (76.8% female, age: 42.3 ± 10.5 y) were analyzed. Most runners (84.4%) had an injury history, with 44.6% experiencing one in the past year. The most common RRI sites included the foot/ankle (30.9%) and knee (22.2%). RRI prevalence was higher in those running >19 miles weekly (48.4%, p = 0.05), but there were no differences based on RT participation status. Among those using RT, relatively more RRIs were observed in runners who trained the hip musculature (50.3%, p = 0.005) and did not include the upper body (61.6%, p < 0.001). A disproportionately high RRI prevalence was found for several of the other risk-reduction strategies. RRIs remain a substantial problem, particularly around the ankle/foot and knee. Higher run volume and performance motives were positively associated with RRIs. Most runners incorporated RRI risk-reduction techniques, with over half using RT. The current study did not determine whether preventative strategies were implemented before or after injury; therefore, prospective studies controlling for previous injuries are required to evaluate the effectiveness of RT in preventing future RRIs.

Treadmill running intensity and post-exercise increase in plasma cardiac troponin I and T-A pilot study in healthy volunteers.

Plasma concentrations of cardiac troponins increase in healthy individuals after strenuous training, but the response to lower exercise intensities has not been characterized. To determine whether exercise at moderate intensity significantly increases plasma cardiac troponins measured with different assays in healthy recreational athletes. Twenty-four self-reported healthy volunteers were instructed to complete three 60-min bouts of treadmill running at variable intensities: High-intensity training (HIT) including a maximal exercise test and an anaerobic threshold test followed by training at 80%-95% of maximum heart rate (HRmax ), Moderate-intensity training (MIT) at 60%-75% of HRmax , and Low-intensity training (LIT) at 45%-55% of HRmax . Blood samples were collected before and at 2, 4, and 6 h after HIT and 4 h after MIT and LIT. Troponin I and T were measured in plasma samples with assays from Abbot, Siemens, and Roche. Plasma troponins measured with all assays were significantly increased compared to baseline after HIT but not after LIT. After HIT, the fraction of all participants with one or more values above the assay-specific 99th percentiles ranged from 13% to 61%. The biomarker criteria for acute myocardial injury were met after HIT for troponin T in 75% of female participants having no clinical evidence of coronary artery disease. High-intensity, but not moderate- or low-intensity, training for 60 min induced a potentially clinically significant increase in plasma cardiac troponins in healthy volunteers. Results exceeding the population 99th percentiles were most frequent with the troponin T assay.

Influence of a COVID-19 induced reduction in game time on the match activity profiles of elite Australian Rules Football players

Assess the influence of a 20% reduction in game time on the volume and intensity of elite AF players’ match activity profiles. GPS technology was used to analyse the movement demands of 45 AF players from the same AFL club during 43 matches across the 2019 and 2020 seasons. GPS data were categorised into measures of volume (total match time [TMT] and total distance [TD]) and intensity (metres per minute [m.min-1], high-intensity running [HIR] distance and m.min-1 [&gt;17 km·h-1], and very-high intensity running [VHIR] distance and m.min-1 [&gt;23 km·h-1]). Volume decreased in 2020 with reductions in TMT (effect size [ES] ± 95% confidence interval [CI] = -1.8 ± 0.2; p &lt; .001) and TD (ES = -1.8 ± 0.2; p &lt; .001) overall, across all positional groups, and quarters. Intensity increased, evidenced by increases in HIR m.min-1 (ES = 0.3 ± 0.1; p &lt; .001), and VHIR m.min-1 (ES = 0.3 ± 0.2; p = .006). HIR m.min-1 increased for midfielders (ES = 0.6 ± 0.3; p = .017). Defenders exhibited increases in HIR m.min-1 (ES = 0.2 ± 0.2; p = .007), and VHIR m.min-1 (ES = 0.4 ± 0.2; p = .010). Intensity of third quarters decreased at a greater rate in 2020 with reductions in m.min-1 (ES = -0.2 ± 0.1; p = .004) and HIR m.min-1 (ES = -0.2 ± 0.1; p = .037) compared to Q1. Systematic reductions in volume were found overall, across positional groups, and quarters. Average movement speed remained relatively stable overall, across quarters and positional groups. Increases in intensity were defined predominately by increases at high and very-high intensity speeds per minute, with defenders exhibiting the greatest increase in intensity and change to their match activity profiles. Longer quarter and three-quarter time breaks, and time between goals preserved intensity.

The impact of progressive overload on the proportion and frequency of positive cardio-respiratory fitness responders

The proportion of individuals whose cardio-respiratory fitness change after endurance training does not exceed the test's measurement error can be 40 %. We determined if progressively increasing treadmill run intensity compared to maintaining the same run intensity, improved the responder proportion to a 6-week 20-minute treadmill training regimen. The intervention response standard deviation method estimated the proportion of responders attributable to progressively increasing run intensity. The mixed-effects model demonstrated V̇O2 peak improved significantly more in the progressive versus constant run intensity group. The proportion of V̇O2 peak responses above the smallest worthwhile change attributable to progressively increasing run intensity was 63.6 %.

Runners with better cardiorespiratory fitness had higher prefrontal cortex activity during both single and exercise-executive function dual tasks: an fNIRS study.

Objective: This study investigated the relationship between executive function and prefrontal cortex oxygenation during exercise in young adults with different Cardiorespiratory fitness (CRF) levels. Methods: A total of 28 amateur runners (n = 14) and sedentary college students (n = 14) were recruited. The maximum oxygen uptake estimated for the sub-maximal intensity run (4.97 miles/h) was used to indicate the different CRF levels. After 1week, participants must complete the Stroop and 2-Back tasks in silence while performing moderate-intensity exercise. Using 19-channel functional near-infrared spectroscopic (fNIRS) to examine changes in prefrontal cortex oxyhemoglobin. Results: There was no significant difference in the correctness of the Stroop and 2-Back tasks between the two groups during exercise, but the amateur runner group showed an acceleration in reaction time. fNIRS results showed that during the exercise 2-Back task, the left dorsolateral prefrontal cortex oxyhemoglobin was higher in the amateur runner group than in the sedentary group. Conclusion: Executive function during exercise was similarly improved in participants with better fitness, suggesting that CRF provides an excellent metabolic reserve and directed allocation for cognitive tasks during exercise.

BLOOD BIOCHEMICAL CHANGES AFTER DRAMATIC INCREASE IN RUNNING TRAINING VOLUME: EXPLORATORY STUDY IN 3 ELITE SOLDIERS

Ultra-Endurance running training is a powerful stressor for all biological systems and depends mainly on its volume and intensity. Although the high physical demands, soldiers are an unstudied group and information on exercise indicators are essential. This study aimed to observe the changes in serum biochemical indicators in previously endurance trained elite soldiers after a 17-week training program with a dramatic increase in running volume. Three subjects (#1: 26 years, 169,5cm; #2: 27 years, 167,9cm; #3: 27 years, 180,7cm) running daily between 10-12 km/day, increased their running volume to prepare the participation in a 100-km ultramarathon race. For 17 weeks the training program included 10-12 sessions per week, corresponding to 200-260 km. Average daily running volume was 35.8±6.2 km. Blood samples were taken for analysis of urea, creatinine, glucose, cholesterol and triglycerides, AST, ALT, CK, aldolase, Na, chloride, P, Ca, K, Fe, Mg and cortisol. Despite a marked drop in iron and a rise in phosphorus, the overall mineral status remained within laboratory reference values. ALT, AST, Aldolase showed slight changes while a marked increase was found in CK. Creatinine decreased and urea maintained the high starting values. Changes of glucose, cholesterol and triglycerides had no clinical significance. After the 17-week the cortisol increased to outside of the reference values in two participants. This study shows that a dramatic increase in running training volume experienced by previous trained runners is mainly reflected in basal blood chemistry through the reduction of iron and creatinine and increase of cortisol.

Reduced myocardial strain of interventricular septum among male amateur marathon runners: a cardiac magnetic resonance study

ObjectivesTo analyze the long-term effect of multiple marathons on cardiac structure and function in amateur marathon runners compared with healthy controls. DesignCross-sectional study using male amateur marathon runners (n = 32) and age-matched cohort of male healthy controls (n = 12). MethodsA total of 32 male amateur marathon runners (age 44 ± 7 years) and 12 male healthy controls (age 42 ± 8 years) underwent cardiac magnetic resonance (CMR). The relevant parameters of cardiac structure and function were studied employing feature-tracking strain analysis. ResultsAmateur marathon runners showed lower heart rates, body mass index and body surface area. The left ventricular (LV) mass index, LV end-diastolic volume index and right ventricular end-systolic volume index were significantly higher in amateur marathon runners compared with healthy controls. Furthermore, walls of interventricular septum (IVS) in amateur marathon runners were thicker than healthy controls. There was no significant difference between two groups in the global myocardial strain (MS) in LV. However, the segmental radial and circumferential strains of the LV were lower in amateur marathon runners compared to healthy controls, specifically in the 8th and 9th segments. Finally, we also found as the total running intensity increased, so did global longitudinal strain. ConclusionsWe reported higher wall thickness and lower regional radial and circumferential strain in the IVS region in amateur marathon runners, suggesting that prolonged and high-intensity exercise may cause cardiac remodeling. Further studies are needed to investigate whether this is an adaptive or maladaptive change in amateur marathon runners.

The effects of street environment features on road running: An analysis using crowdsourced fitness tracker data and machine learning

Urban streets provide environment for road running. The study proposes a non-parametric approach that uses machine learning models to predict road running intensity. The models were developed using route check-in data from Keep, a mobile exercise application, and street geographic information data in Beijing’s core district. The results show that blue space and trail continuity are the most important factors in improving road running intensity. There is an optimum design value for the sky openness and the street enclosure, which need to be balanced with shade while meeting the light of the road. And it is also important to provide appropriate visual permeability. Furthermore, unlike daily activities, it was found that higher function mixture and function density did not have significant positive effects on the road running intensity. This study provides empirical evidence on road running and highlights the key factors that planners, landscape architects, and city managers should consider when design running-friendly urban streets.

Exercise-related abdominal complaints in a large cohort of runners: a survey with a particular focus on nutrition

ObjectivesAbdominal complaints (AC) during exercise are a common problem in runners. Nutrition is known to play a role in exercise-related AC, but information on the role of habitual dietary intake...

Physical Performance in Highest-Level Soccer: Comparison between FIFA World Cup and UEFA Champions League Matches

Match running performance (RP) of Union of European Football Associations Champions League (UCL) and Fédération Internationale De Football Association World Cup (WC) players are often investigated separately; however, no study to simultaneously observed RP in both competitions. Therefore, the main objective of this study was to provide a comparative analysis of RP of professional soccer match-play across two highest-level soccer competitions: UCL and WC. The RPs (UCL; n=244, WC; n=581) of professional soccer players were analyzed using optical systems, and classified according to their playing positions as: central defenders (CD), fullbacks (FB), central midfielders (CM), wide midfielders (WM) and forward (FW). The RP variables included total distance and high intensity running (&gt;5.5 m/s). One-way analysis of variance was used to examine position-specific differences between RP in WC and UCL, while Cohen’s d was used to identify effect sizes. Results indicated that CDs, FBs, CMs, and WMs from UCL covered significantly greater total distance than their counterparts from WC (all moderate effect sizes). In addition, CDs from UCL achieved greater amount of high intensity running than CDs from WC (small effect size). This study demonstrated differences in various aspects of physical performance between two highest-level soccer competitions with variations dependent upon playing position. The findings enabled a more thorough understanding of the physical requirements for playing in UCL and WC, and may have direct consequences for specific training programs.

Running Performance Profile among Playing Positions and Quarters in Elite Female Field Hockey Players

PURPOSE: This study aimed to compare the running-related variables during competitions across playing positions and quarters in elite female field hockey players.METHODS: A total of 136 data from 41 players were collected using GPS units during national-level competitions. The running-related variables included the total distance covered (TD, unit: m), relative distance (RD, unit: m/min), proportion of low-(LID, 0-6 km/h), moderate-( MID, 6.1-15 km/h), and high-intensity (HID, ≥15.1 km/h) distance of the total distance covered (unit: %), and sprint efforts (SE, ≥19.1 km/h, ≥1s; unit: bouts).RESULTS: The defenders’ TD (5,619.77±1,046.14 m) was shorter than that of midfielders (5,475±1,043.33 m) and forwards (4,684.22± 1,066.11 m), and the RD of midfielders (103.64±9.10 m/min) was longer than that of forwards (99.03±10.37 m/min) and defenders (92.42±10.85 m/min). The midfielders had the highest MID(47.08±5.51%), while the highest HID (16.23±3.62%) was observed in the forwards. Defenders performed 35.12±5.25 bouts, with the highest number of sprints among the playing positions. Regardless of the playing positions, 1 quarter had the highest TD, RD, and HID, and the SE was the highest in 4 quarter.CONCLUSIONS: The players’ specific requirements can be managed by practitioners and coaches using the running performance profile; further, it can be used to design training programs containing suitable running volumes to improve players’ performance.

Effects of High-Intensity Warm-Up on 5000-Meter Performance Time in Trained Long-Distance Runners.

Warm-up protocols with high intensities before continuous running provide potential benefits for middle-distance runners. Nevertheless, the effect of high-intensity warm-ups on long-distance runners remains unclear. The purpose of this study was to verify the effect of a high-intensity warm-up protocol on 5000 m performance in trained runners. Thirteen male runners (34 ± 10 years, 62 ± 6 kg, 62.7 ± 5.5 ml/kg/min) performed two 5000 m time trials, preceded by two different warm-ups. One high-intensity warm up (HIWU: 1x 500 m (70% of the running intensity) + 3x 250 m (100% of the running intensity) and one low-intensity warm up (LIWU: 1x 500 m (70% of the running intensity) + 3x 250 m (70% of the running intensity)), where the running intensities were calculated using the results obtained in the Cooper test. Physiological and metabolic responses, and endurance running performance parameters, were evaluated by the Counter Movement Jump (CMJ), running rating of perceived exertion (RPE), blood lactate concentration (BLa), and performance running. Total time for the 5000 m was lower using HIWU when compared to LIWU (1141.4 ± 110.4 s vs. 1147.8 ± 111.0 s; p = 0.03; Hedges' g = 0.66). The HIWU warm-up led to an improvement in pacing strategy during the time trial. After warm-up protocols, the performance on the CMJ was improved only when applying HIWU (p = 0.008). Post warm-up BLa was significantly higher for HIWU vs. LIWU (3.5 ± 1.0 mmol·L-1 vs. 2.3 ± 1.0 mmol·L-1; p = 0.02), with similar behavior for the RPE (p = 0.002), internal load of the session (p = 0.03). The study showed that a high-intensity warm-up protocol can improve performance in the 5000 m in trained endurance runners.

Wheel running intensity effects on mice tendon mechanics

Exercise has numerous effects on the musculoskeletal system, including muscle hypertrophy and tendon remodeling. Although exercise is well documented to affect tendon materials properties, the impacts of exercise intensity are less understood. To study the effects of exercise intensity on adult tendon, we used a line of mice artificially selected for high voluntary wheel running for over 90 generations (High Runner, HR). HR and control line mice were separated into wheel running and sedentary training groups at 9-weeks of age. Wheel activity was quantified using tachometers and collected weekly. After 9 weeks of exercise, mice were sacrificed and stored at -20 °C until the plantarflexor tendons were isolated for processing. Tendon cross-sectional area and length were measured in ImageJ. Tendons were marked with indelible ink for direct strain measurements and then were attached to an ergometer for sinusoidal and ramp-to-failure excursions. Force and lever displacement were recorded directly from the ergometer while actual tissue strain was obtained via high-speed videography. When analyzing our data with body mass as a covariate, our results suggest that exercise or linetype have no significant effect on tendon morphology; however, tendon length is significantly affected by the interaction of linetype and exercise. The interaction of exercise and linetype significantly affected yield and failure strain where wheel training increased strain in control mice and decreased strain in HR mice. Interestingly, wheel exercise and training intensity do not synergistically affect tendon material properties but result in varying changes. Total kilometers ran per day had an inverse relationship with yield and failure strain for control mice whereas HR mice showed no correlation for either; ultimately, no relationships with total kilometers ran per day were significant. Future studies should incorporate histological approaches to understand the tendon compositional changes leading to these variable responses. This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.