Validity of an Interval Taekwondo-Specific Cardiopulmonary Exercise Test.

ABSTRACT: Araujo, MP, Soares, PP, Hausen, MR, Julio, HS, Porto, F, and Gurgel, JL. Validity of an interval taekwondo-specific cardiopulmonary exercise test. J Strength Cond Res 35(7): 1956-1963, 2021-The objective of this study is to propose and validate an interval taekwondo-specific cardiopulmonary exercise test (ITKDtest) and compare it with running cardiopulmonary exercise test (CPET) and a continuous taekwondo-specific cardiopulmonary exercise test (CTKDtest). Fifteen athletes (age 22 ± 4 years; body mass 71.1 ± 10.2 kg; height 178.14 ± 8.3 cm; and body mass index 22.4 ± 2.4 kg·m-2) performed CPET, CTKDtest, and ITKDtest on a counterbalanced order. Oxygen uptake (V̇o2), heart rate (HR), and ventilatory thresholds (VTs 1 and 2) were measured during the 3 tests. ITKDtest started at 30 kicks per minute and increased 10 kicks each 2 minutes, with a period of passive recovery, lasting 1 minute. Interval protocol design simulated the temporal structure of an official taekwondo fight. Significant difference between specific tests was found for V̇o2 VT1 (p = 0.03), V̇o2 VT1 (%V̇o2peak) (p = 0.009), V̇o2 VT2 (p = 0.005), and V̇o2 VT2 (%V̇o2peak) (p = 0.013). Reliability was considered "excellent" for V̇o2peak (α = 0.902; SEM = 0.179), "good" for V̇o2 VT1 (α = 0.708; SEM = 3.823) and HRpeak (α = 0.803; SEM = 2.987), and "fair" for V̇o2 VT2 (α = 0.659; SEM = 4.498) and HR VT2 (α = 0.580; SEM = 8.868). Bland-Altman analyses reported a mean difference of 2.9 ± 6.6 ml·kg-1·min-1 (CPET-ITKDtest) and 1.4 ± 6.1 ml·kg-1·min-1 (CTKDtest-ITKDtest). ITKDtest may be used for measurement of cardiorespiratory variables commonly used in exercise prescription, whereas CTKDtest seems to be a more appropriate method to assess V̇o2 and HR at VTs.

Proposal of a New Specific Cardiopulmonary Exercise Test for Taekwondo Athletes.

The objective of this study is to evaluate the cardiorespiratory variables of Taekwondo athletes while performing incremental exercise test on an ergometer using a ramp protocol and to propose a specific protocol for assessing these physiological variables during Taekwondo practice. Fourteen athletes participated in 2 incremental exercise tests: a treadmill exercise test (TREADtest) and a Taekwondo-specific exercise test (TKDtest). The TKDtest consists in 1-minute stages of kicks with an incremental load between then. The subjects perform kicks each time a sound signal was heard. Heart rate (HR), oxygen uptake (V[Combining Dot Above]O2), and their reserve correspondents (V[Combining Dot Above]O2R and reserve heart rate [HRR]) were divided into quartiles to verify their kinetics along the tests. Significant difference between 2 tests was found only for V[Combining Dot Above]O2R (p = 0.03). Regarding the quartiles, significant differences were found for HR in the first (p = 0.030) and second (p = 0.003). Analyzing the regression curves, significant differences were found for HR for intercept (p = 0.01) and slope (p = 0.05) and HRR for slope (p = 0.02). Analysis showed that significant reliability, with intraclass correlation coefficient (ICC), was found for the V[Combining Dot Above]O2peak (ICC = 0.855, p = 0.003), V[Combining Dot Above]O2 in ventilatory thresholds 1 (ICC = 0.709, p = 0.03) and 2 (ICC = 0.848, p = 0.003). Bland-Altman analyses reported a mean difference ± the 95% limits of agreement of 2.2 ± 8.4 ml·kg·min to V[Combining Dot Above]O2peak. The TKDtest is reliable for measurement of cardiorespiratory variables, and the behavior of these variables differs mainly from TREADtest, probably because of the motor task performed.

Postexercise hypotension after maximal short-term incremental exercise depends on exercise modality.

This study investigated postexercise hypotension (PEH) after maximal cardiopulmonary exercise testing (CPET) performed using different exercise modalities. Twenty healthy men (aged 23 ± 3 years) performed 3 maximal CPETs (cycling, walking, and running), separated by 72 h in a randomized, counter-balanced order. Systolic (SBP) and diastolic blood pressure (DBP), heart rate, cardiac output, systemic vascular resistance (SVR), autonomic function (spontaneous baroreflex sensitivity (BRS) and heart rate variability (HRV)), and energy expenditure (EE) were assessed during a 60-min nonexercise control session and for 60 min immediately after each CPET. Total exercise volume (EE during CPET plus 60 min recovery) was significantly higher in running versus cycling and walking CPETs (P ≤ 0.001). Compared with control, only SBP after running CPET was significantly reduced (Δ = -6 ± 8 mm Hg; P < 0.001). Heart rate and cardiac output were significantly increased (P < 0.001) and SVR significantly decreased (P < 0.001) postexercise. BRS and HRV decreased after all CPETs (P < 0.001), whereas sympatho-vagal balance (low- and high-frequency (LF:HF) ratio) increased significantly after all exercise conditions, especially after running CPET (P < 0.001). Changes in SVR, BRS, sympathetic activity (low-frequency component of HRV), and LF:HF ratio were negatively correlated to variations in SBP (range -0.69 to -0.91; P < 0.001) and DBP (range -0.58 to -0.93; P ≤ 0.002). These findings suggest that exercise mode or the total exercise volume are major determinants of PEH magnitude in healthy men. Because of the running CPET, the PEH was primarily related to a decrease in SVR and to an increase in sympatho-vagal balance, which might be a reflex response to peripheral vasodilatation after exercise.

Parasympathetic reactivation after maximal CPET depends on exercise modality and resting vagal activity in healthy men.

PURPOSE: The main purpose of this study was to investigate parasympathetic reactivation of the heart [evaluated through heart rate recovery (HRR) and HR variability (HRV)] after maximal cardiopulmonary exercise testing (CPET) using three different exercise modalities. METHODS: Twenty healthy men, aged 17 to 28 yr, performed three maximal CPETs (cycling, walking, and running) separated by 72 h and in a randomized, counter-balanced order. HRR was determined from the absolute differences between HRpeak and HR at 1-3 min after exercise. The root mean square of successive R-R differences calculated for consecutive 30-s windows (rMSSD30s) was calculated to assess the parasympathetic reactivation after maximal CPET. RESULTS: Lower HRpeak, VO2peak and energy expenditure were observed after the cycling CPET than the walking and running CPETs (P < 0.001). Both HRR and rMSSD30s were significantly greater during recovery from the cycling CPET compared to the walking and running CPETs (P < 0.001). Furthermore, Δ rMSSD (i.e. resting minus postexercise rMSSD every 30 s into the recovery period) was positively related to the resting high-frequency component (HF), rMSSD, and standard deviation of all normal R-R intervals (SDNN) (rs = 0.89 to 0.98; P < 0.001), and negatively related to the resting low-frequency component (LF) and sympathovagal balance (LF:HF ratio) after all exercise conditions (rs = -0.73 to -0.79 and -0.86 to -0.90, respectively; P < 0.001). CONCLUSIONS: These findings support that parasympathetic reactivation after maximal CPET (as assessed by HRR and rMSSD30s) depends on exercise modality and cardiac autonomic control at rest.

Correlation between cardiac autonomic modulation in response to orthostatic stress and indicators of quality of life, physical capacity, and physical activity in healthy individuals.

Increased heart rate variability (HRV) at rest is frequently associated to maximal oxygen uptake (VO2max), physical activity, and markers of quality of life (QoL). However, the HRV has not been observed during physical exercise or orthostatic (ORT) challenge. This study investigated the associations of HRV changes (ΔHRV) from rest at supine (SUP) to ORT positions with (VO2max), physical activity level, and QoL in young adults. Cardiac autonomic modulation was assessed by spectral analysis of R-R time series measured from SUP to ORT positions in 15 healthy volunteers (26 ± 7 years). Questionnaires were applied for evaluation of QoL (SF-36 score), to estimate (VO2max), and to quantify physical activity (Baecke Sport Score). All HRV indices at SUP, but not ORT, strongly correlated to QoL, estimated (VO2max), and physical activity. The ΔHRV from SUP to ORT showed significant correlations with all questionnaire scores (r = 0.52-0.61 for low frequency and r = -0.61 to -0.65 for high frequency, p ≤ 0.05). Higher vagal activity at rest and greater changes in adrenergic and parasympathetic modulation from SUP to ORT were detected in the volunteers exhibiting higher scores of QoL, estimated (VO2max), and physical activity. Taken together, the level of neural adaptations from resting SUP position to active standing, and physical activity and QoL questionnaires seem to be a simple approach to understand the physiological and lifestyle adaptations to exercise that may be applied to a large sample of subjects in almost any sports facilities at a low cost.

Cholinergic stimulation with pyridostigmine improves autonomic function in infarcted rats.

In the present study we evaluated the effects of short-term pyridostigmine bromide (0.14 mg/mL) treatment started early after myocardial infarction (MI) on left ventricular (LV) and autonomic functions in rats. Male Wistar rats were divided into control, pyridostigmine, infarcted and infarcted + pyridostigmine-treated groups. Pyridostigmine was administered in the drinking water, starting immediately after MI or sham operation, for 11 days. Left ventricular function was evaluated indirectly by echocardiography and directly by LV catheterization. Cardiovascular autonomic control was evaluated by baroreflex sensitivity (BRS), heart rate variability (HRV) and pharmacological blockade. All evaluations started after 7 days pyridostigmine treatment and were finalized after 11 days treatment. Pyridostigmine prevented the impairment of +dP/dT and reduced the MI area in infarcted + pyridostigmine compared with infarcted rats (7 ± 3% vs 17 ± 4%, respectively). Mean blood pressure was restored in infarcted + pyridostigmine compared with infarcted rats (103 ± 3 vs 94 ± 3 mmHg, respectively). In addition, compared with the infarcted group, pyridostigmine improved BRS, as evaluated by tachycardic (1.6 ± 0.2 vs 2.5 ± 0.2 b.p.m./mmHg, respectively) and bradycardic (-0.42 ± 0.01 vs -1.9 ± 0.1 b.p.m./mmHg) responses, and reduced the low frequency/high frequency ratio of HRV (0.81 ± 0.11 vs 0.24 ± 0.14, respectively). These improvements are probably associated with increased vagal tone and reduced sympathetic tone in infarcted + pyridostigmine compared with infarcted rats. In conclusion, the data suggest that short-term pyridostigmine treatment started early after MI can improve BRS, HRV and parasympathetic and sympathetic tone in experimental rats. These data may have potential clinical implications because autonomic markers have prognostic significance after MI.

Cardiovascular responses to passive static flexibility exercises are influenced by the stretched muscle mass and the Valsalva maneuver.

BACKGROUND: The respiratory pattern is often modified or even blocked during flexibility exercises, but little is known about the cardiovascular response to concomitant stretching and the Valsalva maneuver (VM) in healthy subjects. OBJECTIVES: This study evaluated the heart rate (HR), systolic blood pressure (SBP), and rate-pressure product (RPP) during and after large and small muscle group flexibility exercises performed simultaneously with the VM. METHODS: Asymptomatic volunteers (N = 22) with the following characteristics were recruited: age, 22 ± 3 years; weight, 73 ± 6 kg; height, 175 ± 5 cm; HR at rest, 66 ± 9 BPM; and SBP at rest, 113 ± 10 mmHg. They performed two exercises: four sets of passive static stretching for 30 s of the dorsi-flexion (DF) of the gastrocnemius and the hip flexion (HF) of the ischio-tibialis. The exercises were performed with (V+) or without (V-) the VM in a counterbalanced order. The SBP and HR were measured, and the RPP was calculated before the exercise session, at the end of each set, and during a 30-min post-exercise recovery period. RESULTS: The within-group comparisons showed that only the SBP and RPP increased throughout the sets (p < 0.05), but no post-exercise hypotension was detected. The between-group comparisons showed that greater SBP increases were related to the VM and to a larger stretched muscle mass. Differences for a given set were identified for the HR (the HFV+ and HFV- values were higher than the DFV+ and DFV- values by approximately 12 BPM), SBP (the HFV+ value was higher than the DFV+ and DFV- values by approximately 12 to 15 mmHg), and RPP (the HFV+ value was higher than the HFV- value by approximately 2000 mmHGxBPM, and the HFV+ value was higher than the DFV+ and DFV- values by approximately 4000 mmHGxBPM). CONCLUSION: Both the stretched muscle mass and the VM influence acute cardiovascular responses to multiple-set passive stretching exercise sessions.

Acute effects of stretching exercise on the heart rate variability in subjects with low flexibility levels.

The study investigated the heart rate (HR) and heart rate variability (HRV) before, during, and after stretching exercises performed by subjects with low flexibility levels. Ten men (age: 23 ± 2 years; weight: 82 ± 13 kg; height: 177 ± 5 cm; sit-and-reach: 23 ± 4 cm) had the HR and HRV assessed during 30 minutes at rest, during 3 stretching exercises for the trunk and hamstrings (3 sets of 30 seconds at maximum range of motion), and after 30 minutes postexercise. The HRV was analyzed in the time ('SD of normal NN intervals' [SDNN], 'root mean of the squared sum of successive differences' [RMSSD], 'number of pairs of adjacent RR intervals differing by >50 milliseconds divided by the total of all RR intervals' [PNN50]) and frequency domains ('low-frequency component' [LF], 'high-frequency component' [HF], LF/HF ratio). The HR and SDNN increased during exercise (p < 0.03) and decreased in the postexercise period (p = 0.02). The RMSSD decreased during stretching (p = 0.03) and increased along recovery (p = 0.03). At the end of recovery, HR was lower (p = 0.01), SDNN was higher (p = 0.02), and PNN50 was similar (p = 0.42) to pre-exercise values. The LF increased (p = 0.02) and HF decreased (p = 0.01) while stretching, but after recovery, their values were similar to pre-exercise (p = 0.09 and p = 0.3, respectively). The LF/HF ratio increased during exercise (p = 0.02) and declined during recovery (p = 0.02), albeit remaining higher than at rest (p = 0.03). In conclusion, the parasympathetic activity rapidly increased after stretching, whereas the sympathetic activity increased during exercise and had a slower postexercise reduction. Stretching sessions including multiple exercises and sets acutely changed the sympathovagal balance in subjects with low flexibility, especially enhancing the postexercise vagal modulation.

Cardiovascular responses to passive static flexibility exercises are influenced by the stretched muscle mass and the Valsalva maneuver

BACKGROUND: The respiratory pattern is often modified or even blocked during flexibility exercises, but little is known about the cardiovascular response to concomitant stretching and the Valsalva maneuver (VM) in healthy subjects. OBJECTIVES: This study evaluated the heart rate (HR), systolic blood pressure (SBP), and rate-pressure product (RPP) during and after large and small muscle group flexibility exercises performed simultaneously with the VM. METHODS: Asymptomatic volunteers (N = 22) with the following characteristics were recruited: age, 22 ± 3 years; weight, 73 ± 6 kg; height, 175 ± 5 cm; HR at rest, 66 ± 9 BPM; and SBP at rest, 113 ± 10 mmHg. They performed two exercises: four sets of passive static stretching for 30 s of the dorsi-flexion (DF) of the gastrocnemius and the hip flexion (HF) of the ischio-tibialis. The exercises were performed with (V+) or without (V-) the VM in a counterbalanced order. The SBP and HR were measured, and the RPP was calculated before the exercise session, at the end of each set, and during a 30-min post-exercise recovery period. RESULTS: The within-group comparisons showed that only the SBP and RPP increased throughout the sets (p<0.05), but no post-exercise hypotension was detected. The between-group comparisons showed that greater SBP increases were related to the VM and to a larger stretched muscle mass. Differences for a given set were identified for the HR (the HFV+ and HFV- values were higher than the DFV+ and DFV- values by approximately 12 BPM), SBP (the HFV+ value was higher than the DFV+ and DFV- values by approximately 12 to 15 mmHg), and RPP (the HFV+ value was higher than the HFV- value by approximately 2000 mmHGxBPM, and the HFV+ value was higher than the DFV+ and DFV- values by approximately 4000 mmHGxBPM). CONCLUSION: Both the stretched muscle mass and the VM influence acute cardiovascular responses to multiple-set passive stretching exercise sessions.

Cardiac output and oxygen uptake relationship during physical effort in men and women over 60 years old.

This study investigated the relationship between oxygen uptake (VO(2)), cardiac output (Q), stroke volume (SV), and heart rate (HR) in 54 men and 77 women (age = 69 +/- 5 years) during incremental effort. Subjects performed a maximal cycle-ergometer test and VO(2) was directly measured. HR and SV were assessed by ECG and cardiograph impedance. Regression equations were calculated for Q-VO(2), HR-VO(2), and Q-HR relationships. The equations obtained for women were (a) Q (l min(-1)) = 2.61 + 4.67 VO(2) (l min(-1))(r(2) = 0.84); (b) HR (bpm) = 62.03 + 46.55 VO(2) (l min(-1)) (r (2) = 0.72); (c) SV (ml) 100:6[1 - e(-2.6 VO2 (1 min-1))] (r (2) = 0.41); (d) HR (bpm) = 41.48 + 9.24 Q (l min(-1)) (r (2) = 0.73). Equations for men were (a) Q (l min(-1)) = 2.52 + 5.70 VO(2) (l min(-1)) (r (2) = 0.89); (b) HR (bpm) = 66.31 + 32.35 VO(2) (l min(-1)) (r (2) = 0.72); (c) [1 - e(-1.7 VO2 (1 min-1))] (r (2) = 0.47); (d) HR (bpm) = 56.33 + 5.25 Q (l min(-1)) (r (2) = 0.69). The intercepts for Q-VO(2) and HR-VO(2) equations were similar for both genders, but the slopes were different (P < 0.05). The SV increased from baseline to 50-60% of VO(2) peak in both groups. No gender effect was found in SV increasing pattern, but the absolute values were in general higher for men (P > 0.05). A significant difference between men and women was observed for both slopes and intercepts in the Q-HR relationship (P < 0.05). In conclusion, (a) Q-VO(2) relation was linear during progressive effort; (b) regression intercepts were similar, but the slopes were higher for men compared to women; (c) SV-VO(2) relationship was nonlinear and maximum SV was reached at very submaximal workload; (d) older men exhibited higher Q upward potential as well higher SV but lower HR for a given submaximal workload than women of similar age.