Percentage Of Maximal Heart Rate Research Articles

Determination of Second Lactate Threshold Using Near-infrared Spectroscopy in Elite Cyclists.

The use of near-infrared spectroscopy could be an interesting alternative to other invasive or expensive methods to estimate the second lactate threshold. Our objective was to compare the intensities of the muscle oxygen saturation breakpoint obtained with the Humon Hex and the second lactate threshold in elite cyclists. Ninety cyclists performed a maximal graded exercise test. Blood capillary lactate was obtained at the end of steps and muscle oxygenation was continuously monitored. There were no differences (p>0.05) between muscle oxygen oxygenation breakpoint and second lactate threshold neither in power nor in heart rate, nor when these values were relativized as a percentage of maximal aerobic power or maximum heart rate. There were also no differences when men and women were studied separately. Both methods showed a highly correlation in power (r=0.914), percentage of maximal aerobic power (r=0.752), heart rate (r=0.955), and percentage of maximum heart rate (r=0.903). Bland-Altman resulted in a mean difference of 0.05±0.27 W·kg-1, 0.91±4.93%, 0.63±3.25 bpm, and 0.32±1.69% for power, percentage of maximal aerobic power, heart rate and percentage of maximum heart rate respectively. These findings suggest that Humon may be a non-invasive and low-cost alternative to estimate the second lactate threshold intensity in elite cyclists.

The Effect of Intensity Soccer Training Sessions on Marked Biochemical Indicators of Blood Acidity of Saudi Young Soccer Players.

PurposeTo assess the effect of low-to-moderate-intensity exercise on specific blood biomarkers and blood acidity in young Saudi Arabian professional soccer players.MethodsA total of 43 professional soccer players participated in the current study. A cross-sectional research method was used to compare the changes in the following blood biomarkers: calcium, magnesium, glucose, anion-gap metabolic acidosis, and carbon dioxide, after a range of low-to-moderate intensity training sessions. Measurements were taken in two soccer training sessions (Day 1, and Day 2). The exercise intensity was estimated by heart rate percentage of maximal heart rate. Wilcoxon signed-rank testing was used to analyze the results.ResultsSignificant differences were found between and pre-and post-training sessions for anion-gap metabolic acidosis: Day 1: 12.55 vs 15.4 mmol/L; Day 2: 14.15 vs 16.35 mmol/L; and magnesium: Day 1: 0.82 vs 0.74 mmol/L; Day 2: 0.85 vs 0.74 mmol/L. Exercise caused anion-gap metabolic acidosis concentrations to rise post-training; magnesium levels decreased after training sessions on Day 1 and Day 2.ConclusionThe concentrations of anion-gap metabolic acidosis and magnesium were significantly affected by exercise intensity in the subjects, the former rose post-training while the latter fell. More studies are required to investigate the effects of different exercise intensities on other blood biomarkers in soccer players.

Weekly Fluctuations in Salivary Hormone Responses and Their Relationships With Load and Well-Being in Semiprofessional, Male Basketball Players During a Congested In-Season Phase.

To assess weekly fluctuations in hormonal responses and their relationships with load and well-being during a congested in-season phase in basketball players. Ten semiprofessional, male basketball players were monitored during 4 congested in-season phase weeks consisting of 3 weekly matches. Salivary hormone variables (testosterone [T], cortisol [C], and T:C ratio) were measured weekly, and external load (PlayerLoad™ and PlayerLoad per minute), internal load session rating of perceived exertion, percentage of maximum heart rate (HR), summated HR zones, and well-being were assessed for each training session and match. Significant (P < .05) moderate to large decreases in T were found in the third and fourth weeks compared with the first week. Nonsignificant moderate to large decreases in C were apparent in the last 2 weeks compared with previous weeks. Summated HR zones and perceived sleep significantly (P < .05) decreased in the fourth week compared with the first week; whereas, percentage of maximum HR significantly (P < .05) decreased in the fourth week compared with the second week. No significant relationships were found between weekly changes in hormonal responses and weekly changes in load and overall wellness. A congested schedule during the in-season negatively impacted the hormonal responses of players, suggesting that T and C measurements may be useful to detect fluctuations in hormone balance in such scenarios. The nonsignificant relationships between weekly changes in hormonal responses and changes in load and well-being indicate that other factors might induce hormonal changes across congested periods in basketball players.

Utilizing Heart Rate as an Exercise Intensity Training Method to Determine Overtraining for Collegiate Long- Distance Runners

In recent years, heart rate has become easier to measure and collect data. Heart rate is a direct measurement of the autonomic nervous system. Therefore, it is utilized in aerobic training to determine an appropriate exercise intensity within a general population. Long distance runners utilize blood lactate threshold-based and maximum oxygen uptake-based speeds and paces as their exercise intensity during training. Overtraining is often determined by rate of perceived exertion by the athlete. There has yet to be an established physiological marker to indicate overtraining in collegiate long-distance runners. There are strong correlations between blood lactate threshold and VO2 with heart rate physiological markers such as percent maximal heart rate (%Hrmax) and heart rate variability (HRV). HR-based physiological markers that can be utilized to indicate overtraining are %Hrmax with intensity zones, %HRR with intensity zones, HRV, and cardiac drift. However, further studies need to be conducted to establish appropriate utilization of each physiological marker.

769 Differential pharmacological modulation of arrhythmic phenotype in catecholaminergic polymorphic ventricular tachycardia: not all betablockers are the same

Abstract Aims Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited arrhythmogenic disorder that predisposes patients to develop catecholamine-mediated ventricular arrhythmias (VA), manifesting as exercise- or emotion-induced syncope or cardiac arrest. Due to the catecholaminergic nature of CPVT, exercise stress test (EST) represents the most important diagnostic test. Although widely used in clinical practice to monitor response to therapy, how BBs modulate the occurrence of ventricular arrhythmias during EST in CPVT patients is unclear. To compare the relative efficacy of different classes of betablockers (BBs, β1-selective BBs vs. nadolol) on the arrhythmic manifestations during ESTs performed off-therapy and on-therapy in patients with CPVT. Methods and results We selected 72 patients (45 females) with pathogenic or likely pathogenic variants on RYR2 or CASQ2 from our cohort of 246 genotype-positive CPVT patients, who had at least one EST off-therapy and at least one EST during BB therapy. Overall, 507 ESTs (77 ESTs off-therapy, 29 ESTs during β1-selective BBs, and 401 during nadolol) were prospectively collected over 11.1 ± 6.8 years of follow-up and analysed, with a median of 5 ESTs per patient [interquartile range (IQR): 3–10 ESTs, range: 2–27 ESTs]. In the absence of therapy, VT was documented in 46/77 (60%) cases. BB therapy with nadolol significantly reduced VT at EST to 10% (41/398; P &amp;lt; 0.001). Conversely, β1-selective BBs did not significantly decrease VT incidence at EST (13/29, 45%, P = 0.289) as compared to baseline. Importantly, nadolol was superior in preventing VT both when compared to off-therapy [odds ratio (OR): 33.9, 95% confidence interval (CI): 15.6–73.5, P &amp;lt; 0.001] but also when compared to β1-selective BBs [OR: 18.0, 95% CI: 6.0–53.5, P &amp;lt; 0.001]. Although β1-selective BBs significantly increased the total exercise time free of arrhythmias (median 248 s, IQR: 212–315 s) as compared to baseline (median 83 s, IQR: 12–207 s; P &amp;lt; 0.001), arrhythmia-free exercise time during nadolol (median 381 s, IQR: 251–543 s) was significantly longer as compared to both off-therapy (P &amp;lt; 0.001) and β1-selective BBs (P = 0.020). Multivariate mixed effects logistic regression confirmed that at parity of time of occurrence of first arrhythmia and percentage of maximal heart rate reached, both of which were significantly associated to VT occurrence (P = 0.001 for both), the use of nadolol (OR: 0.23; 95% CI: 0.09–0.60; P = 0.011) was independently associated with decreased incidence of VT. Focusing on the 14 patients (overall 133 ESTs) who had at least one ESTs after the occurrence of VT in nadolol, we dissected the effect of dose increase on the probability of VT reoccurrence. Following the documentation of breakthrough VT, increasing the dose of nadolol by 0.5 mg/kg reduced by 2.5 times the probability of having a recurrence of VT (OR: −2.49, 95% CI: −3.96 to − 1.0; P &amp;lt; 0.001). Conclusions Once CPVT is diagnosed, nadolol at 1 mg/kg/day should be used as preferred therapy as it has been shown to suppress VT in most patients. In rare instances in which VA persist despite an adequate nadolol dose, dose increase to 1.5 mg/kg/day may represent an efficacious antiarrhythmic strategy.

Systematic Review and Meta-Analysis of the Relationship between Actual Exercise Intensity and Rating of Perceived Exertion in the Overweight and Obese Population.

The number of overweight (OW) and obese (OB) children, adolescents, and adults has increased globally. Exercise intensity, both actual and perceived, is a significant factor in a variety of health-related investigations and rehabilitation trainings. Despite this, literature on the connection between actual exercise intensity and the rating of perceived exertion (RPE) in overweight and obese populations is lacking. A systematic review, meta-analysis, combined analysis of variance (Brown–Forsythe ANOVA), and Spearman correlation were performed to fill this gap. After preliminary assessments, ten studies were classified as having a low risk of bias and a degree of heterogeneity (I2 = 34%; p = 0.05). The RPE scores (F = 0.032; p = 0.859), physiological index (percentage of maximal heart rate (%HRmax) (F = 0.028; p = 0.869), and percentage of maximal oxygen uptake (%VO2max) (F = 2.434; p = 0.136) demonstrated consistency without being significantly different between the normal weight (NW) and OW/OB groups. The RPE scores varied by age (NW (coefficient values) = 0.677 ***, OW = 0.585 **), as well as by indoor temperature (OW only, coefficient values = 0.422 *), body mass index (NW (coefficient values) = 0.516 **, OW = 0.580 **), and test time (NW only, coefficient values = 0.451 *). We conclude that RPE is appropriate for the following OW and OB people: (1) those who are older than 21.5 (the lowest age in the group of ≥18) years old and younger than 58.6 (the highest age in the group of ≥18) years old, without any other diseases, and (2) those who engage in low-intensity exercise while maintaining a standard indoor temperature. Future studies may address alternative techniques for increasing the reliability of longitudinal comparisons and gender comparisons, as well as investigate other possible confounding factors.

What Is Moderate to Vigorous Exercise Intensity?

A variety of health benefits associated with physical activity depends upon the frequency, intensity, duration, and type of exercise. Intensity of exercise is the most elusive of these elements and yet has important implications for the health benefits and particularly cardiovascular outcomes elicited by regular physical activity. Authorities recommend that we obtain 150min of moderate to vigorous intensity physical activity (MVPA) each week. The current descriptions of moderate to vigorous intensity are not sufficient, and we wish to enhance understanding of MVPA by recognition of important boundaries that define these intensities. There are two key thresholds identified in incremental tests: ventilatory and lactate thresholds 1 and 2, which reflect boundaries related to individualized disturbance to homeostasis that are appropriate for prescribing exercise. VT2 and LT2 correspond with critical power/speed and respiratory compensation point. Moderate intensity physical activity approaches VT1 and LT1 and vigorous intensity physical activity is between the two thresholds (1 and 2). The common practice of prescribing exercise at a fixed metabolic rate (# of METs) or percentage of maximal heart rate or of maximal oxygen uptake (V̇O2max) does not acknowledge the individual variability of these metabolic boundaries. As training adaptations occur, these boundaries will change in absolute and relative terms. Reassessment is necessary to maintain regular exercise in the moderate to vigorous intensity domains. Future research should consider using these metabolic boundaries for exercise prescription, so we will gain a better understanding of the specific physical activity induced health benefits.

Infant Cardiopulmonary Resuscitation Quality While Walking Fast: A Simulation Study.

This study focuses on the characteristics (feasibility, resuscitation quality, and physical demands) of infant cardiopulmonary resuscitation (CPR) on the forearm during fast walking, performed by a trained lay rescuer. Twenty-one university students from the infant education degree participated in a randomized crossover simulation study to compare a standard pediatric CPR versus a walking pediatric CPR with a manikin on the rescue forearm. Each rescuer performed 2 resuscitation tests of 2 minutes on the infant manikin. Cardiopulmonary resuscitation, physiological, and perceived effort variables were measured. The quality of chest compressions was higher in standard pediatric CPR than in walking pediatric CPR (72% vs 51%; P < 0.001) and overall CPR quality (59% vs 49%; P = 0.02). There were no differences between ventilation quality (47% vs 46%). Walking pediatric CPR presented a higher percentage of maximum heart rate (52% vs 69%; P < 0.001) and perceived exertion rate (2 vs 5; P < 0.001). Participants walked an average of 197 m during the test. In conclusion, pediatric walking CPR is feasible although it represents a slight quality decrease in a simulation infant CPR setting. The option "CPR while walking fast to a safe place" seems to be suitable in terms of safety both for the victim and the rescuer, as well as CPR quality in special circumstances.

Pattern of the Heart Rate Performance Curve in Subjects with Beta-Blocker Treatment and Healthy Controls.

(1): Heart rate performance curve (HRPC) in incremental exercise was shown to be not uniform, causing false intensity estimation applying percentages of maximal heart rate (HRmax). HRPC variations are mediated by β-adrenergic receptor sensitivity. The aim was to study age and sex dependent differences in HRPC patterns in adults with β-blocker treatment (BB) and healthy controls (C). (2): A total of 535 (102 female) BB individuals were matched 1:1 for age and sex (male 59 ± 11 yrs, female 61 ± 11 yrs) in C. From the maximum incremental cycle ergometer exercise a first and second heart rate (HR) threshold (Th1 and Th2) was determined. Based on the degree of the deflection (kHR), HRPCs were categorized as regular (downward deflection (kHR > 0.1)) and non-regular (upward deflection (kHR < 0.1), linear time course). (3): Logistic regression analysis revealed a higher odds ratio to present a non-regular curve in BB compared to C (females showed three times higher odds). The odds for non-regular HRPC in BB versus C decreased with older age (OR interaction = 0.97, CI = 0.94–0.99). Maximal and submaximal performance and HR variables were significantly lower in BB (p < 0.05). %HRmax was significantly lower in BB versus C at Th2 (male: 77.2 ± 7.3% vs. 80.8 ± 5.0%; female: 79.2 ± 5.1% vs. 84.0 ± 4.3%). %Pmax at Th2 was similar in BB and C. (4): The HRPC pattern in incremental cycle ergometer exercise is different in individuals receiving β-blocker treatment compared to healthy individuals. The effects were also dependent on age and sex. Relative HR values at Th2 varied substantially depending on treatment. Thus, the percentage of Pmax seems to be a stable and independent indicator for exercise intensity prescription.

Effect of 8-Week Aerobic Exercise on Anthropometric Indices, Atherogenic Index of Plasma and Some Cardiovascular Risk Factors in Inactive Men

Background and Aims The sedentary lifestyle is related to the incidence of various diseases and metabolic disorders. Atherogenic Index of Plasma (AIP) can be considered as an appropriate criterion predicting coronary heart disease. This study aimed to investigate the Effect of 8-week aerobic training on anthropometric Indices, the Atherogenic Index of Plasma, and some cardiovascular risk factors in inactive men. Methods In the current quasi-experimental study, 40 inactive employees with a Mean±SD age of 36.17±8.97 years and body mass index of 26.60±4.12 kg/m2 after obtaining testimonial voluntarily performed aerobic exercise training for 8 weeks (each session 45 to 60 minutes) with 70 percent of maximal heart rate. Blood samples were taken before and after exercise to measure serum variables. Data were analyzed by paired t-test at the significant level of P&lt;0.05. Results Statistical analysis showed that after 8 weeks of aerobic exercise, Body fat percentage (P=0.04), cholesterol (P=0.001), LDL/HDL ratio (P=0.03), TG/HDL ratio (P=0.01), TC/HDL ratio (P=0.001), and apo-B (P=0.01) decreased significantly. Also, VO2max (P=0.011) and HDL (P=0.010) increased dramatically after 8 weeks of participation in aerobic activity. Conclusion According to the results, an increase in physical activity can probably reduce the risk of cardiovascular disease. Also, physical activity with lowering the risk factors of developing CVD events and significant prevention of its progression, the beneficial properties of physical activity are underscored, and promoting its effectiveness as support for healthier lifestyles in the community and particularly among inactive men is emphasized.

Indoor Cycling Energy Expenditure: Does Sequence Matter?

Although cycling class intensity can be modified by changing interval intensity sequencing, it has not been established whether the intensity order can alter physiological and perceptual responses. Therefore, this study aimed to determine the effects of interval intensity sequencing on energy expenditure (EE), physiological markers, and perceptual responses during indoor cycling. Healthy volunteers (10 males = 20.0 ± 0.8years; 8 females = 21.3 ± 2.7years) completed three randomly ordered interval bouts (mixed pyramid—MP, ascending intervals—AI, descending intervals—DI) including three 3-min work bouts at 50%, 75%, and 100% of peak power output (PPO) and three 3-min recovery periods at 25% PPO. Heart rate (HR) and oxygen consumption (VO2) were expressed as percentages of maximal HR (%HRmax) and VO2 (%VO2max). EE was computed for both the work bout and for the 5-min recovery period. Session Rating of Perceived Exertion (sRPE) and Exercise Enjoyment Scale (EES) were recorded. No differences emerged for % HRmax (MP = 73.3 ± 6.1%; AI = 72.1 ± 4.9%; DI = 71.8 ± 4.5%), % VO2max (MP = 51.8 ± 4.6%; AI = 51.4 ± 3.9%; DI = 51.3 ± 4.5%), EE (MP = 277.5 ± 39.9 kcal; AI = 275.8 ± 39.4 kcal; DI = 274.9 ± 42.1 kcal), EES (MP = 4.9 ± 1.0; AI = 5.3 ± 1.1; DI = 4.9 ± 0.9), and sRPE (MP = 4.9 ± 1.0; AI = 5.3 ± 1.1; DI = 4.9 ± 0.9). EE during recovery was significantly (p < 0.005) lower after DI (11.9 ± 3.2 kcal) with respect to MP (13.2 ± 2.5 kcal) and AI (13.3 ± 2.5 kcal). Although lower EE was observed during recovery in DI, interval intensity sequencing does not affect overall EE, physiological markers, and perceptual responses.

The non-invasive coronary flow reserve predicts exercise capacity in patients undergoing cardiac rehabilitation

The benefit of exercise on peripheral muscles is established but the exact role of the coronary microcirculation in exercise capacity after cardiac rehabilitation (CR) is unclear. Our aim was to test the relationship between non-invasive coronary flow reserve (CFR) and exercise capacity in patients undergoing CR after acute myocardial infarction (AMI). CFR was performed by transthoracic Doppler echocardiography in the left anterior descending artery 24 h after angioplasty (CFR1) and after 20 sessions of CR program (at 4 ± 1 months)(CFR2) in 60 consecutive patients (57 ± 11 years, 30% women) with an anterior AMI successfully treated by primary coronary angioplasty. CFR was performed in a modified parasternale view using intravenous adenosine infusion (0.14 mg/kg/min within 2 minutes). CR program consisted of a half hour of fractioned exercise added of a half hour session of general gymnastics and bodybuilding. To test the exercise capacity, symptom limited exercise echocardiography was performed just after the CFR2, in a semi-supine position, starting at 25 watts, with 20-25 watts increments of workload every two minutes. CFR was measured successfully in all patients, and CFR2 was significantly higher than CFR1 (2.9 ± 0.65 vs. 1.9 ± 0.4, P < 0.001). Though CFR1 was correlated to left ventricular systolic function and its improvement at follow-up (all, P < 0.01), CFR2 was independently related to exercise capacity (mean workload 100 ± 30 watts, percent maximal heart rate 83 ± 12%, no ischemia, no new wall motion abnormalities in all tests) after adjusting for age, sex, and body mass index ( r = 0.6, P < 0.01). CFR predicts exercise capacity in patients undergoing a CR program after AMI. The improvement of CFR contributes to cardiac performance.

Influence of a Training Academy on the Parasympathetic Nervous System Reactivation of Firefighter Recruits-An Observational Cohort Study.

Sudden cardiac death (SCD) is the leading type of line-of-duty death among firefighters. An inability to restore parasympathetic nervous system (PSNS) control after activity is associated with SCD. Post-exercise heart rate recovery (HRR) provides unique insight into reactivation of the PSNS. Thus, the purpose of this study was to examine longitudinal changes in HRR responses of 25 male firefighter recruits. HR data were collected after submaximal exercise at week 1 (W1), week 6 (W6), and week 15 (W15) of their training at an academy. Percent maximal heart rate (%MHR) measures were computed at each HRR time point (%MHR0, %MHR15, %MHR30, %MHR45, %MHR60, %MHR120, %MHR180) and absolute HRR values were calculated at 30 s (ΔHRR30), 60 s (ΔHRR60), 120 s (ΔHRR120), and 180 s (ΔHRR180). After controlling for age and percent body fat, there was no statistically significant interaction between Week × HRR (p = 0.730), and there were no changes in ΔHRR30, ΔHRR60, and ΔHRR120, and ΔHRR180 indices across time. However, %MHR at W6 and W15 was significantly lower than %MHR at W1 at every HRR time point (ps < 0.001). Therefore, although the firefighter recruit training academy elicited positive training adaptations, changes in PSNS reactivation after submaximal activity were not identified.

Effects of different small-sided games on blood lactate and GH/IGF-1 axis responses in young soccer players

Soccer and its intense workouts cause lactate accumulation and extensive metabolic changes. This study, therefore, aimed to compare the percentage of maximum heart rate (%HRmax), blood lactate, growth hormone (GH), and insulin-like growth factor‑1 (IGF-1) responses across different formats of small-sided games (SSG) in young soccer players. Twenty-four soccer players (mean age: 17.1 ± 1.12 years, weight 67.28 ± 1.65 kg and body mass index 20.8 ± 1.18 kg/m2) were randomly divided into three equal groups, including control, 2 vs. 2 (8 periods of 2 min separated by 1 min of passive recovery, with a pitch of 20 m × 25 m) and 4 vs. 4 (4 periods of 4 min separated by 2 min of passive recovery, with a pitch of 28 m × 35 m). Blood samples were taken immediately before and after small-sided games. The results showed that the heart rate increased significantly in young soccer players at different minutes of SSG (p ≤ 0.05). The comparison of these two SSG did not show any significant differences on lactate and somatotropic hormone concentrations (p > 0.05), although each alone significantly increased lactate, GH and IGF‑1 levels compared to control group (p < 0.05). Hence, it can be concluded that due to the sufficient intensity of these two modes of SSG, the cellular relationship between the GH/IGF‑1 axis and lactate helps improve the physiological capacity of young soccer players. However, further studies were needed to consider more accurate effects of these variables (lactate, GH and IGF-1) with two SSG modalities (2 vs. 2 and 4 vs. 4).

Relationship between Oxygen Uptake, Heart Rate, and Perceived Effort in an Aquatic Incremental Test in Older Women.

Different parameters can be used to control the intensity of aerobic exercises, a choice that should consider the population and exercise environment targeted. Therefore, our study aimed to verify the relationship between oxygen uptake (VO2), heart rate (HR), rating of perceived exertion (RPE), and cadence during an aquatic incremental test in older women. Nine older women (64.3 ± 4.4 years) engaged in a water-based aerobic training performed an aquatic incremental test using the stationary running exercise (cadence increases of 15 b·min−1 every 2 min) until participants’ volitional exhaustion. VO2, HR, and RPE data were measured, and the percentage of peak VO2 (%VO2peak) and percentage of maximal HR (%HRmax) were calculated. Linear and polynomial regression analyses were performed (α = 0.05). Polynomial regressions revealed the best adjustments for all analyses. Data showed a significant relationship (p < 0.001) between %VO2peak and %HRmax (r = 0.921), %VO2peak and RPE (r = 0.870), and %HRmax and RPE (r = 0.878). Likewise, significant relationships between cadence (p < 0.001) and %VO2peak (r = 0.873), %HRmax (r = 0.874), and RPE (r = 0.910) were also observed. In summary, the physiological, subjective, and mechanical variables investigated were highly associated during an aquatic incremental test to exhaustion in older women. Therefore, these different parameters can be employed to adequately prescribe water-based programs according to preference and availability.

Workload and well-being across games played on consecutive days during in-season phase in basketball players.

This study aimed to quantify and compare workload and well-being across basketball games played on consecutive days during the in-season phase. Seven players (mean [SD]: age, 20.8 [1.6] y; stature, 195.0 [5.4] cm; body mass, 88.3 [4.2] kg; training experience, 11.6 [3.7] y) competing in the second-tier Lithuanian league were recruited. Changes in workload and well-being were monitored across six NKL games in three separate weeks during the in-season phase, with two games per week played on Friday (Day 1) and Saturday (Day 2). External workload was determined as PlayerLoad (PL) and PL per minute (PL/min) via microsensors. Internal workload was determined as percentage of maximum heart rate (%HRmax), summated heart rate zones (SHRZ) workload, and session-rating of perceived exertion (sRPE) workload. Well-being was evaluated using questionnaires assessing fatigue, sleep quality, general muscle soreness, stress levels and mood. Linear mixed models and effect size analyses were used to compare workload and well-being between Day 1 and Day 2. Significantly lower PL/min (P=0.029; ES=0.26, small), greater perception of fatigue (P<0.001; ES=1.31, large) and lower total well-being score (P<0.001; ES=0.59, small) were observed for basketball games played on Day 2 compared to games played on Day 1. Two games played on consecutive days elicited similar game workloads with higher perceived fatigue and lower well-being in the second game day. These findings suggest basketball coaches using recovery strategies to optimize player well-being during congested game schedules.

Physiological aspects and energetic contribution in 20s:10s high-intensity interval exercise at different intensities.

BackgroundOne of the most popular high-intensity interval exercises is the called “Tabata Protocol”. However, most investigations have limitations in describing the work intensity, and this fact appears to be due to the protocol unfeasibility. Furthermore, the physiological demands and energetic contribution during this kind of exercise remain unclear.MethodsEight physically active students (21.8 ± 3.7 years) and eight well-trained cycling athletes (27.8 ± 6.4 years) were enrolled. In the first visit, we collected descriptive data and the peak power output (PPO). On the next three visits, in random order, participants performed interval training with the same time structure (effort:rest 20s:10s) but using different intensities (115%, 130%, and 170% of PPO). We collected the number of sprints, power output, oxygen consumption, blood lactate, and heart rate.ResultsThe analysis of variance for multivariate test (number of sprints, power output, blood lactate, peak heart rate and percentage of maximal heart rate) showed significant differences between groups (F = 9.62; p = 0.001) and intensities (F = 384.05; p < 0.001), with no interactions (F = 0.94; p = 0.57). All three energetic contributions and intensities were different between protocols. The higher contribution was aerobic, followed by alactic and lactic. The aerobic contribution was higher at 115%PPO, while the alactic system showed higher contribution at 130%PPO. In conclusion, the aerobic system was predominant in the three exercise protocols, and we observed a higher contribution at lower intensities.

The First Lactate Threshold Is a Limit for Heavy Occupational Work.

Long-term heavy physical work often leads to early retirement and disability pension due to chronic overload, with a need to define upper limits. The aim of this study was to evaluate the value of the first lactate threshold (LTP1) as a physiological marker for heavy occupational work. A total of 188 male and 52 female workers performed an incremental cycle ergometer test to determine maximal exercise performance and the first and second lactate (LTP1; LTP2) and ventilatory thresholds (VT1; VT2). Heart rate (HR) recordings were obtained during one eight-hour shift (HR8h) and oxygen uptake was measured during 20 minutes of a representative work phase. Energy expenditure (EE) was calculated from gas-exchange measures. Maximal power output (Pmax), maximal oxygen consumption (VO2 max) and power output at LTP1 and LTP2 were significantly different between male and female workers. HR8h was not significantly different between male and female workers. A significant relationship was found between Pmax and power output at LTP1. HR8h as a percentage of maximum HR significantly declined with increasing performance (Pmax:r = −0.56; p < 0.01; PLTP1:r = −0.49; p < 0.01). Despite different cardio-respiratory fitness-levels; 95.4% of all workers performed their usual work below LTP1. It is therefore suggested that LTP1 represents the upper limit for sustained heavy occupational work; which supports its use to determine work capability and assessing the limits of heavy occupational work.

Psycho-physiological aspects of small combats in taekwondo: impact of area size and within-round sparring partners.

The study investigated physiological and psychological responses to taekwondo combat sessions as a function of different area sizes and within-round sparring partners. Twenty-four adolescent (age: 17 ± 1years) male (n = 12) and female (n = 12) taekwondo athletes participated in the study. Each athlete confronted 1 (1vs.1; no sparring partner change) or 2 (1vs.2; within-round sparring partner change every minute) opponents in different area sizes (i.e., 4 × 4 m, 6 × 6 m, and 8 × 8 m) for 2 min. Blood lactate concentration ([La]) was measured before and after bouts. Heart rate (HR) was measured throughout the contests and rating of perceived exertion was assessed after bouts. Mean HR (HRmean) and percentage of maximum HR (%HRmax) determined during a 20-m multistage shuttle run test were used for analysis. Mood states were assessed before and after bouts and physical enjoyment was analyzed after bouts. The results showed higher HRmean and %HRmax values for the 1vs.1 compared to the 1vs.2 condition (p < 0.001) and [La] values were higher at post-combat measurements (p < 0.001). Moreover, tension and fatigue were higher in 6 × 6 m compared with 8 × 8 m (p = 0.022 and p = 0.023, respectively) and anger was higher in 6 × 6 m and 8 × 8 m in comparison with 4 × 4 m (p = 0.012 and p = 0.043, respectively). Confusion increased from before to after bouts (p < 0.001), from 4 × 4 m and 6 × 6 m area sizes to 8 × 8 m (p = 0.001 and p = 0.018, respectively), and from 1vs.1 to 1vs.2 (p < 0.001). Furthermore, vigour decreased from before to after bouts (p < 0.01). Taekwondo combat sessions are a specific conditioning exercise for athletes. Thus, coaches can use the 1vs.1 condition to elicit higher HR responses and 6 × 6 m area size to induce higher psychological stress, mimicking what occurs during a competition.

Wheelchair Basketball Exercise Intensity in Youth

Children and youth with physical disabilities are at the greatest risk for inactivity, emphasizing the need for evidence-based activity options in recreation, rehabilitation, and post-rehabilitation settings. To determine if a wheelchair sport enabled youth participants to sustain moderate to vigorous physical activity (MVPA), the primary purpose of this study was to document exercise intensity of wheelchair basketball (WBB) among youth. The secondary purpose was to examine the influence of age, disability type, and training condition on intensity. Thirty-four youth with physical disabilities (MAge = 15.73 ± 2.57 yrs; MPlaying Experience = 4.32 ± 2.77 yrs) participated in three wheelchair basketball training sessions that included tactical drills (M = 113 min), and scrimmage (M = 57 min) training conditions. Percentage of maximum heart rate (HRMax), mean accelerometer vector counts per minute, and rate of perceived exertion (RPE) were assessed across 3 practices and collapsed into one training intensity score for each variable. Mean HRMax was 66±8% and mean accelerator vector counts were 6,055±1439 per minute, indicating that participants sustained MVPA during WBB training. Perceived effort, however, was distinct from the actual physical demand as mean RPE was 3.1±1.5. Age did not influence intensity scores but players who had a congenital or acquired spinal cord injury and were participating in scrimmage activity demonstrated higher exercise intensity. These findings support the ability of youth WBB players to sustain MVPA. This activity can be recommended as an evidence-based initiative in sport, rehabilitation or post-rehabilitation settings.