Psychological Factors Associated With Fear of Falling Avoidance Behavior in Parkinson's Disease: The Role of Depression, Anxiety, and Catastrophizing.

PURPOSE: The purpose of this study was to examine the relationship between psychological factors (depression, anxiety, and catastrophizing) and fear of falling avoidance behavior (FFAB) among individuals with Parkinson's disease (PD). METHODS: A secondary analysis of cross-sectional data from 59 individuals with PD using hierarchical multiple regression. RESULTS: Disease severity (Movement Disorder Society - Unified PD Rating Scale) and catastrophizing (Consequences of Falling Questionnaire (CoF)) explained approximately 48.2% of the variance in the FFAB Questionnaire scores (P < .001). Catastrophizing was the only significant psychological variable (P < .001). The damage to identity subscale of the CoF was significant in the final model (P < .001). CONCLUSIONS: Catastrophizing about the consequences of falls explained the largest portion of variability in FFAB after controlling for disease severity. Catastrophizing about the immediate consequences of falling may play a prominent role in FFAB and may be a potential treatment target for mitigating FFAB.

Effect of exercise in a desert environment on physiological and subjective measures.

Green exercise is beneficial to emotional and physiological measures, however, the US has large desert areas. We aimed to determine if exercise in a desert (brown) environment extends similar benefits to green. Participants (N = 10) completed baseline measures (PRE), 30-min seated rest (SIT), and 30-min self-paced walking (WALK) in: indoor, outdoor urban, green, and two brown environments. Heart rate (HR), blood pressure (BP), and measures of stress, comfort, and calm were obtained. After SIT, HR was elevated in urban vs green (p = 0.05). Systolic BP was lower after SIT compared to PRE and WALK (p = 0.05). Brown and green returned greater comfort and calm scores (p = 0.001). Stress was lower following WALK than PRE and SIT (p < 0.01). Comfort and calm were greatest in natural environments, and exercise significantly reduced perceived stress. Taken together, these data provide evidence that exercise in a desert environment is just a beneficial as the exercise performed in a green environment. Abbreviations: ANCOVA: analysis of covariance; ANOVA: analysis of variance; AU: arbitrary units; BP: blood pressure; BSL: below sea level; DBP: diastolic blood pressure; HR: heart rate; PRE: baseline measurement; PS: perceived stress; SBP: systolic blood pressure; SIT: measurement following 30-min seated rest; WALK: measurement following 30-min self-paced walking.

A High-Intensity Exercise Boot Camp for Persons With Parkinson Disease: A Phase II, Pragmatic, Randomized Clinical Trial of Feasibility, Safety, Signal of Efficacy, and Disease Mechanisms.

BACKGROUND AND PURPOSE: The feasibility, safety, and efficacy of a high-intensity multimodal exercise program (aerobic, strengthening, and balance training) have not been well vetted in persons with Parkinson disease (PD). Thus, the primary aim was to determine whether a high-intensity multimodal exercise boot camp (HIBC) was both feasible and safe in persons with PD. The secondary aim was to determine whether the program would produce greater benefit than a usual care, low-intensity exercise program (UC). An exploratory aim was to determine whether these programs affected putative disease-modifying mechanisms. METHODS: Twenty-seven participants (19 men and 8 women) were randomized into 8 weeks of either the HIBC or UC supervised by physical therapists. For feasibility, participation, and meeting, Centers for Disease Control and Prevention (CDC) exercise guidelines were assessed. For safety, adverse events were monitored. For efficacy, the following outcome domains were assessed before and after participation: balance, motor activity, endurance and fatigue, strength, mental health, and quality of life. For disease-modifying mechanisms, circulating brain-derived neurotrophic factor (BDNF) and its genotype, superoxide dismutase, and cytokines (tumor necrosis factor-α, interleukin-6, and interleukin-10) were monitored. RESULTS: The HIBC was better at attaining CDC guidelines (P = 0.013) and spent more minutes in higher-intensity exercise per week (P < 0.001). There were no differences in adverse events (P = 0.419). The HIBC experienced significant improvements in 7/31 outcomes versus 3/31 in the UC arm. BDNF improved significantly for both groups from pre- to posttests (Ps ≤ 0.041) and an improved anti-inflammatory was observed for both groups. DISCUSSION AND CONCLUSIONS: A high-intensity multimodal exercise boot camp was feasible and safe in persons with PD. Compared with usual care, there were no differences in adverse events. Moreover, the high-intensity multimodal exercise program produced more improvement across more domains than usual care. Our results also suggest a possible link between improvement in outcomes and an improved anti-inflammatory milieu.Video Abstract available for more insights from the authors (see Video, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A244).

Autonomy enhances running efficiency.

Performer autonomy has been shown to contribute to effective motor performance and learning. Autonomy support is therefore a key factor in the OPTIMAL theory of motor learning (Wulf, G., & Lewthwaite, 2016). The purpose of the present study was to examine whether supporting individuals' need for autonomy by giving them choices would increase movement efficiency. Such a finding would be consistent with the OPTIMAL theory prediction that autonomy facilitates the coupling of goals and actions. Participants (N = 32) were asked to run at a submaximal intensity (65% of VO2 max) for 20 minutes. Before the run, participants in a choice group were able to choose 5 of 10 photos as well as the order in which they would be shown to them on a computer screen during the run. Control group participants were shown the same photos, in the same order, chosen by their counterparts in the choice group. Throughout the run, oxygen consumption and heart rate were significantly lower in the choice group than the control group. Thus, providing autonomy support resulted in enhanced running efficiency. The present findings are in line with the notion that autonomy facilitates goal-action coupling.

Effect of 8 Weeks of Hospital-Based Resistance Training Program on TCD4+ Cell Count and Anthropometric Characteristic of Patients With HIV in Tehran, Iran: A Randomized Controlled Trial.

Ghayomzadeh, M, SeyedAlinaghi, S, Shamsi, MM, Rezaei, S, Earnest, CP, Akbarnejad, S, Taj, L, Mohraz, M, Navalta, JW, Ghasemi, P, and Voltarelli, FA. Effect of 8 weeks of hospital-based resistance raining program on TCD4+ cell count and anthropometric characteristic of patients with HIV in Tehran, Iran: A randomized controlled trial. J Strength Cond Res 33(4): 1146-1155, 2019-We examined the effects of an 8-W circuit resistance training (RES) program using elastic bands and body weight on TCD4+ cell counts and anthropometry in patients with HIV. Patients (N = 21) receiving antiretroviral therapy were randomly assigned to resistance training (RES; n = 14) or control (CON; n = 7) groups. RES (3/W) consisted of training with elastic bands and bodyweight training focusing on major muscle groups. CON received standard care. Statistical analyses were performed using general linear models adjusted for age, sex, length of infection, and respective baseline measures. The primary outcome was TCD4+, and secondary outcomes were anthropometry indices. Tertiary assessments explored Pearson correlations surrounding the relationship between changes in anthropometry and TCD4+. We observed significant increases in TCD4+ count accompanying RES training (105.50 cells·mm, 95% confidence interval [CI], 47.42-163.59), whereas CON significantly decreased (-41.01 cells·mm, 95% CI, -126.78 to 44.76). Significant between-group differences were noted (p < 0.02; n = 0.42). We also observed significant reductions in fat mass for RES (1.18 kg, 95% CI = 1.80 to -0.56) vs. increased fat mass for CON (1.21 kg, 95% CI, 0.31 to 2.11). Significant between-group differences were noted (p = 0.001, n = 0.64). Similar effects were noted for lean body mass. No significant changes were observed for body mass. Significant correlations were observed for fat mass (r = -0.699, p = 0.001) and lean mass (r = 0.553, p = 0.017), but not body mass (r = -0.390, p = 0.109) vs. changes in TCD4+. Our results suggest that the RES program used in this study is effective for improving TCD4+ status and body composition in patients with HIV.

Carbohydrate Loading Practice in Bodybuilders: Effects on Muscle Thickness, Photo Silhouette Scores, Mood States and Gastrointestinal Symptoms.

A common practice among bodybuilders is the use of carbohydrate loading to improve physical appearance during competition, while limited documented data is available about this issue. The aim of the present study was to evaluate muscle thickness, mood states, gastrointestinal symptoms and subjective silhouette assessment following carbohydrate loading in bodybuilders. Twenty-four male bodybuilders were evaluated at the weighing period following three days of carbohydrate depletion (M1), and 24h of carbohydrate loading leading up to the competition (M2), stratified into: no carbohydrate load (NC, n = 9) and carbohydrate loading (CL, n =1 5). The silhouette scale, Brunel mood scale (BRUMS), muscle thickness (ultrasound), circumferences, and gastrointestinal symptoms (GIS) were evaluated at M1 and M2. The NC displayed no differences in muscle thickness and circumferences between M1 and M2. Body mass, muscle thickness (elbow flexors, a combination of biceps brachii/ brachialis muscle, and triceps brachii) and circumferences (chest, hip, thigh, arm, calves, and forearm) increased significantly (p < 0.05) in the CL at M2. There was a significant increase in photo silhouette scores (p < 0.05) in the CL at M2. There was no significant difference in mood states between groups or time. The most reported GIS was constipation: 7/9 (NC) and 9/15 (CL) during M1 and 6/9 (NC), and 5/15 (CL) at M2 with symptoms described as 'moderate' or 'severe'. Diarrhea was reported by 7/15 CL (4/15 as severe). These data suggest that carbohydrate loading may contribute to an acute increase in muscle volume and physical appearance, however, it needs to be better planned to minimize gastrointestinal symptoms in bodybuilders.

Effects of Fatigue on Balance in Individuals With Parkinson Disease: Influence of Medication and Brain-Derived Neurotrophic Factor Genotype.

BACKGROUND AND PURPOSE: Because falls can have deleterious consequences, it is important to understand the influence of fatigue and medications on balance in persons with Parkinson disease (PD). Thus, the purpose of this study was to investigate the effects of fatigue on balance in individuals with PD. Because brain-derived neurotrophic factor (BDNF) has been shown to be related to motor performance, we also explored its role. METHODS: A total of 27 individuals (age = 65.4 ± 8.1 years; males = 14, females = 13) with neurologist-diagnosed PD with 13 genotyped for BDNF as Val66Val, 11 as Val66Met, 2 as Met66Met (1 refused). Participants were tested both on and off medication, 1 week apart. On both days, they completed a pre- and posttest separated by a fatiguing condition. Factorial analyses of variance were performed for the following balance domains: (1) anticipatory postural responses; (2) adaptive postural responses; (3) dynamic balance; (4) sensory orientation; and (5) gait kinematics. For BDNF, t-tests were conducted comparing genotype for the pre-post difference scores in both the on and off medication states. RESULTS: There were no interactions between time (pre- and postintervention) and medication for any of the domains (Ps ≥ 0.187). Participants with BDNF Met alleles were not significantly different from Val66Val participants in balance (Ps ≥ 0.111) and response to a fatiguing condition (Ps ≥ 0.070). DISCUSSION AND CONCLUSIONS: Fatigue does not appear to have a detrimental effect on balance, and there was not a differential effect of medication in individuals with PD. These results also indicate that participants with a BDNF Met allele did not have a greater decay in function after a fatiguing condition.Video Abstract available for more insights from the authors (see Video, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A196).

Exercise in a natural environment increases program compliance in people with chronic migraine: A pilot cross-over randomized trial.

Adverse side effects from pharmacological treatments cause people with migraine to delay or avoid taking medication. Exercise is effective, but the effect of environment is unknown. The purpose was to determine if a natural environment affects monthly migraine load. Sedentary individuals (8 female, 1 non-binary) who experienced migraines participated. Participants completed one month of exercise (3 x week, 30-min, 60-70% estimated HRmax) indoors as well as in a natural outdoor environment in a randomized counterbalanced order. Migraine load was determined using the Headache Impact Test (HIT-6) and Migraine Disability Assessment (MIDAS) at the beginning and end of each month. Data were analyzed using repeated measures ANOVA. No interactions were evident for HIT-6 (p = 0.80), MIDAS (p = 0.72), migraine days (p = 0.508), or pain intensity (p = 0.66). No main effects were noted. Compliance was greater in the outdoor environment, with more exercise sessions completed in nature (Indoor = 72%, Outdoor = 90%, p < 0.001). Exercise environment did not impact MIDAS or HIT-6 questionnaire results, number of migraine days, or pain intensity. While there was no reduction in migraine load, it is possible that other health benefits were experienced due to greater compliance in a natural environment.

A Randomized Controlled Trial, Non-Nutrition Based mHealth Program: The Potential Impact on Dietary Intake in College Students.

The aims of this study were to (1) explore this sample's pre- and post-intervention dietary intake, specifically the macro- and micronutrients, and their eating habits related to location of consumption and use of electronic devices, and (2) compare this sample's nutritional measures to the current Dietary Guidelines 2020 to 2025. Twenty-eight participants were included in the secondary data analysis. Participants reported a total of 822 items consumed during this study. Most items were consumed at home (n = 629, 76.5%). We found significant differences in the intake of energy, protein, total fat, carbohydrates, total vegetables, total grains, and total meat in different locations. For most of these measures, consumption at home and/or restaurants resulted in a greater magnitude of consumption than at other locations (e.g., car, daycare). Participants reported consuming most of their energy and nutrients while either using electronic devices alone (n = 365, 44.4%) or using no devices (n = 346, 42.1%). Significant differences were found among three measures including energy, total fat, and total fiber. The majority of the macronutrients (total fiber, fruits, vegetables, meat, and dairy) consumed by our sample were under the threshold recommended in the 2020 to 2025 Dietary Guidelines.

How an IJES Working Group Grappled with the Complexities of Three Letters-DEI-With the Goal to Broaden Inclusion and Representation in Exercise Science Research.

A self-study of International Journal of Exercise Science (IJES) publications from 2008 through 2021 revealed a sex-data gap in participant and corresponding author representation. This finding prompted the creation of the IJES Working Group for Opportunity, Representation, and Diverse Perspectives. We are a collaborative team of authors, reviewers, and editors, spanning both rural and urban teaching- and research-focused institutions, who assembled regularly starting in September 2023. The goal was to contemplate potential challenges and opportunities around diversity, equity, and inclusion (DEI), elicit discourse, and broaden inclusion and representation in exercise science research. Our group identified six main challenges/opportunities: 1) Mixed Definitions and Applications of DEI Principles; 2) Competing Lifeviews and Worldviews; 3) Oversight and Enforcement of DEI Principles in IJES; 4) Oversight and Enforcement of DEI Principles in the Broader Field; 5) IJES is a Home for Developing Scholars; and 6) Lag Time for Creating Change in IJES. As a growing international journal, we depend on a diverse group of authors, reviewers, editors, and readers to achieve our mission. Accordingly, the Working Group encourages impactful, inclusive research that broadens representation within exercise science.

The 2024 International Journal of Exercise Science Position Stand on Inclusion.

The International Journal of Exercise Science (IJES) Working Group for Opportunity, Representation, and Diverse Perspectives was tasked with developing a position stand to provide guidance in critical areas of inclusion. We present to authors, reviewers, and all readership IJES ideals to utilize in practice. Key points are presented, followed by a deeper look with greater explanation into the areas of inclusive language, diversity and inclusion in research, and accessibility. The same approach is presented for the areas of age, disability status, gender identity and sexual orientation, race, and ethnicity with attention to Indigenous Communities, religion, socioeconomic status, and neurodiversity. Person-first language is encouraged, with the acknowledgment that the preference of different community members may vary. IJES is committed to maintaining an environment that is welcoming to all identities so that they feel valued, respected, and included.

Interventional effects of plumbagin on experimental ulcerative colitis in mice.

Plumbagin (1) is a naphthoquinone constituent of plants that have been used in traditional systems of medicine since ancient times. In the present study, the role of 1 was examined on the amelioration of ulcerative colitis, an inflammatory bowel disease that is not curable currently. Plumbagin was tested at a dose of 6-10 mg/kg body weight in acute and chronic disease models. Diseased mice receiving 1 at 8-10 mg/kg demonstrated a significant suppression of disease symptoms in both models. However, body weight loss was not restored in either of the models. Levels of proinflammatory cytokines (TNF-α, IFN-γ, and IL-17) were reduced significantly by 1 in mice suffering from chronic disease, while cytokine levels remained unaffected in mice with acute disease. However, the percentage of inflammatory (CD14+/CD16+) monocytes present in peripheral blood was significantly reduced by >3-fold (p < 0.05) in treatment groups relative to controls in the acute model. Histological evaluations exhibited the restoration of goblet cells, crypts, and the submucosa along with a significant reduction in monocyte aggregation in colon sections from mice receiving treatment with 1. Restoration in colon size was also observed in the treatment groups.

Effects of exercise-induced fatigue on postural balance: a comparison of treadmill versus cycle fatiguing protocols.

The authors of this study examined the effects of muscle fatigue on balance indices and recovery time in recreationally trained individuals after incremental tests on a treadmill and a cycle ergometer. Sixteen participants (male N = 11, female N = 5) (mean age = 21.2 ± 2 years) completed this study. Balance measures were performed on a Biodex Balance System via the Dynamic Balance Test. Balance was measured pre-exercise, immediately post-exercise, and at 3-, 6-, 9-, 12-, 15-, 18-, and 21-min post-exercise. Immediately following the fatiguing treadmill test, balance increased significantly in the overall stability index (SI) (from 4.38 ± 2.48 to 6.09 ± 1.80) and the anterior/posterior index (API) (from 3.49 ± 2.18 to 5.28 ± 1.81) (p < 0.01). Immediately following the fatiguing cycle test, balance was not altered significantly in SI or API. Balance was not altered significantly for the medial/lateral index for either exercise test at any time point. Additionally, there were no significant differences in time to recovery. At 12-min post-exercise, all indices were below pre-exercise values, indicating that fatiguing exercise has a positive effect on balance over time. These results are consistent with previous research, suggesting that any effects of fatigue on balance are seen immediately and are diminished as time after exercise increases.

Implications for cisgender female underrepresentation, small sample sizes, and misgendering in sport and exercise science research.

A sex-data gap, from testing primarily males, results in a lack of scientific knowledge for other groups (females, transgender individuals). It is unknown whether typical recruitment and participant characterization causes incorrect statistical decisions, and three factors were evaluated: 1) underrepresenting cisgender females, 2) recruiting small sample sizes, 3) misgendering. Data from the National Health and Nutrition Examination Survey (2003-2004) were evaluated for sex differences after removing missing values (N = 3,645; F = 1,763). Disparities were determined by utilizing sample sizes common in sport and exercise science research; mean sample size N = 187, median sample size N = 20. Participants were randomly allocated into datasets in an imbalanced manner (33.5% females, 66.5% males). Potential effects of misgendering were determined at rates of 2% and 5%. Differences between the complete data set and expected decisions were conducted through Chi-squared (χ2) goodness of fit with significance at p < .05. When the entire dataset was evaluated as if a sex testing disparity was present, decisions were not altered (χ2 = .52, p = .47). Differences were observed for mean sample size (χ2 = 4.89, p = .027), median sample size (χ2 = 13.52, p < .001), and misgendering at 2% (χ2 = 13.52, p = < .001) and 5% (χ2 = 13.52, p = < .001). Recruitment practices in sport and exercise science research should be revisited, as testing primarily cisgender males has consequences, particularly in small sample sizes. Misgendering participants also has consequences on ultimate decisions and interpretations of data, regardless of sample size. Inclusiveness is needed in helping all individuals feel valued and respected when participating in sport and exercise science research.

Time of Day and Chronotype-Dependent Synchrony Effects Exercise-Induced Reduction in Migraine Load: A Pilot Cross-Over Randomized Trial.

Migraines are the most common cause of chronic pain. Effective, non-pharmacological strategies to reduce migraine load, like exercise, are needed, but it is unclear how exercise timing and chronotype modulate the effects. We sought to determine the effects of time-of-day of exercise, and synchrony with one's chronotype, on migraine load. We performed a pilot cross-over randomized trial where participants with chronic migraine completed two one-month exercise interventions, consisting of either morning exercise (before 09:00 a.m.) or evening exercise (after 7:00 p.m.) in a randomized repeated measures cross-over design (Clinical Trial #NCT04553445). Synchrony was determined by exercise time and chronotype (i.e., a morning type participant exercising in the morning is 'in-sync,' while an evening type participant exercising in the morning is 'out-of-sync'). Migraine burden, and anthropometric assessment occurred before and after each month of exercise. Data was analyzed using repeated measures ANOVA with significance accepted at p < 0.05. When comparing morning and evening exercise, there was no significant improvements in any migraine-related parameters. However, when comparing in-sync and out-of-sync exercise, we found that migraine burden was only improved following in-sync exercise, while no benefits were seen in out-of-sync exercise. Our data suggests that exercise timing has limited impact, but synchrony with chronotype may be essential to decrease migraine load in chronic migraineurs.

Fear of Falling Avoidance Behavior in Parkinson's Disease: Most Frequently Avoided Activities.

BACKGROUND: Fear of falling avoidance behavior (FFAB) is common in Parkinson's disease (PD). OBJECTIVES: The objectives of the study are to determine what activities are most avoided due to FFAB among people with PD and whether any associations exist with demographic factors or fall history. METHOD: Cross-sectional analysis of 174 individuals with PD using the Modified FFAB Questionnaire. RESULTS: Walking in dimly lit, unfamiliar places, and different surfaces, lifting and carrying objects, walking in crowded places, recreational/leisure activities, and going up/downstairs were most avoided. Fallers reported more FFAB (ps < .029). FFAB for certain activities was associated with increased or decreased odds of falling. CONCLUSION: Individuals with PD avoid walking in compromised situations and engaging in recreational/leisure activities due to FFAB. While excessive FFAB may increase the odds of falling, protective forms may be associated with decreased odds. Targeting FFAB among individuals with PD may increase safe participation in meaningful occupations in the home and community.

Heart rate processing algorithms and exercise duration on reliability and validity decisions in biceps-worn Polar Verity Sense and OH1 wearables.

Consumer wearable technology use is widespread and there is a need to validate measures obtained in uncontrolled settings. Because no standard exists for the treatment of heart rate data during exercise, the effect of different approaches on reliability (Coefficient of Variation [CV], Intraclass Correlation Coefficient [ICC]) and validity (Mean Absolute Percent Error [MAPE], Lin's Concordance Correlation Coefficient [CCC)] were determined in the Polar Verity Sense and OH1 during trail running. The Verity Sense met the reliability (CV < 5%, ICC > 0.7) and validity thresholds (MAPE < 5%, CCC > 0.9) in all cases. The OH1 met reliability thresholds in all cases except entire session average (ICC = 0.57). The OH1 met the validity MAPE threshold in all cases (3.3-4.1%), but not CCC (0.6-0.86). Despite various heart rate data processing methods, the approach may not affect reliability and validity interpretation provided adequate data points are obtained. It is also possible that a large volume of data will artificially inflate metrics.

IJES Self-Study on Participants' Sex in Exercise Science: Sex-Data Gap and Corresponding Author Survey.

A sex-data gap exists between females and males within the sport and exercise science literature, and implications are far-reaching. The purpose of this work was to (a) heed recent calls and scrutinize data from within IJES to address the gap and (b) gain insight on self-identified sex of IJES corresponding authors. The present self-study included all published manuscripts from 2008 through 2021. A total of 851 publications were included, and 806 (94.7%) reported data on participant sex. There was a difference between publications that included only females (n = 132) versus only males (n = 215), and three publications reported data on sex according to non-binary identifications (0.4%). There was an overall difference between the number of female (n = 54,153; 35.9%) and male (n = 96,890; 64.1%) participants. To gain insight on self-identified sex of corresponding authors, we performed an IRB-approved research study. Among 761 unique corresponding authors, 168 individuals provided 157 usable responses-58 biological females (36.9%) and 99 biological males (63.1%). We fully support the prerogative of researchers to ethically conduct investigations and encourage open-mindedness and inclusion in future research. With data revealing an approximate one-third female (36%) and two-thirds male (64%) composition, and corresponding author feedback on self-identified sex being similar (36.9% and 63.1%, respectively), we propose a new concept that should be analyzed: is the sex-data gap representative of the composition of the field? We are not excusing the sex-data gap issue as if it cannot be addressed, and we urge others to join us in researching this line of inquiry.

Assessing the Validity of Several Heart Rate Monitors in Wearable Technology While Mountain Biking.

Purpose: This study sought to assess the validity of several heart rate (HR) monitors in wearable technology during mountain biking (MTB), compared to the Polar H7® HR monitor, used as the criterion device. Methods: A total of 20 participants completed two MTB trials while wearing six HR monitors (5 test devices, 1 criterion). HR was recorded on a second-by-second basis for all devices analyzed. After data processing, validity measures were calculated, including 1. error analysis: mean absolute percentage errors (MAPE), mean absolute error (MAE), and mean error (ME), and 2. Correlation analysis: Lin's concordance correlation coefficient (CCC) and Pearson's correlation coefficient (r). Thresholds for validity were set at MAPE < 10% and CCC > 0.7. Results: The only device that was found to be valid during mountain biking was the Suunto Spartan Sport watch with accompanying HR monitor, with a MAPE of 0.66% and a CCC of 0.99 for the overall, combined data. Conclusion: If a person would like to track their HR during mountain biking, for pacing, training, or other reasons, the devices best able to produce valid results are chest-based, wireless electrocardiogram (ECG) monitors, secured by elastic straps to minimize the movement of the device, such as the Suunto chest-based HR monitor.