The Decremental Protocol as an Alternative Protocol to Measure Maximal Oxygen Consumption in Athletes

2016 ◽  
Vol 11 (8) ◽  
pp. 1094-1099 ◽  
Author(s):  
Katrina Taylor ◽  
Jeffrey Seegmiller ◽  
Chantal A. Vella
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Repeated Measures ◽  
Maximal Oxygen Consumption ◽  
Incremental Test ◽  
Repeated Measures Analysis ◽  
Alpha Level ◽  
Incremental Protocol ◽  
Main Effects ◽  
Over Time

Purpose:To determine whether a decremental protocol could elicit a higher maximal oxygen consumption (VO2max) than an incremental protocol in trained participants. A secondary aim was to examine whether cardiac-output (Q) and stroke-volume (SV) responses differed between decremental and incremental protocols in this sample. Methods:Nineteen runners/triathletes were randomized to either the decremental or incremental group. All participants completed an initial incremental VO2max test on a treadmill, followed by a verification phase. The incremental group completed 2 further incremental tests. The decremental group completed a second VO2max test using the decremental protocol, based on their verification phase. The decremental group then completed a final incremental test. During each test, VO2, ventilation, and heart rate were measured, and cardiac variables were estimated with thoracic bioimpedance. Repeated-measures analysis of variance was conducted with an alpha level set at .05. Results:There were no significant main effects for group (P = .37) or interaction (P = .10) over time (P = .45). VO2max was similar between the incremental (57.29 ± 8.94 mL · kg–1 · min–1) and decremental (60.82 ± 8.49 mL · kg–1 · min–1) groups over time. Furthermore, Q and SV were similar between the incremental (Q 22.72 ± 5.85 L/min, SV 119.64 ± 33.02 mL/beat) and decremental groups (Q 20.36 ± 4.59 L/min, SV 109.03 ± 24.27 mL/beat) across all 3 trials. Conclusions:The findings suggest that the decremental protocol does not elicit higher VO2max than an incremental protocol but may be used as an alternative protocol to measure VO2max in runners and triathletes.

scholarly journals Caffeine effects on velocity selection and physiological responses during RPE production

2016 ◽  
Vol 41 (10) ◽  
pp. 1077-1082 ◽  
Author(s):  
James M. Green ◽  
Alyssa Olenick ◽  
Caroline Eastep ◽  
Lee Winchester
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Repeated Measures ◽  
Perceived Exertion ◽  
Statistical Significance ◽  
Maximal Oxygen Consumption ◽  
Ratings Of Perceived Exertion ◽  
Caffeine Ingestion ◽  
Recreational Runners ◽  
Velocity Selection

Caffeine (CAF) blunts estimated ratings of perceived exertion (RPE) but the effects on RPE production are unclear. This study examined effects of acute caffeine ingestion during treadmill exercise where participants exercised at prescribed RPE 4 and 7. Recreational runners (maximal oxygen consumption = 51.4 ± 9.8 mL·kg−1·min−1) (n = 16) completed a maximal treadmill test followed by trials where they selected treadmill velocity (VEL) (1% grade) to produce RPE 4 and RPE 7 (10 min each). RPE production trials followed CAF (6 mg·kg−1) or placebo (PLA) (counterbalanced) ingestion. Participants were blinded to treadmill VEL but the Omni RPE scale was in full view. Repeated-measures ANOVA showed a main effect (trial) for VEL (CAF ∼5 m·min−1 faster) for RPE 4 (p = 0.07) and RPE 7 (p = 0.03). Mean heart rate and oxygen consumption responses were consistently higher for CAF but failed to reach statistical significance. Individual responses to CAF were labeled positive using a criterion of 13.4 m·min−1 faster for CAF (vs. PLA). Ten of 32 trials (31%) were positive responses. In these, systematic increases were observed for heart rate (∼12 beats·min−1) and oxygen consumption (∼5.7 mL·kg−1·min−1). Blunted/stable respiratory exchange ratio values at higher VEL for positive responders suggest increased free fatty acid reliance during CAF. In conlusion, mean results show a mild effect of CAF during RPE production. However, individual responses more clearly indicate whether a true effect is possible. Trainers and individuals should consider individual responses to ensure effectively intensity regulation.

Responses to Intermittent Swimming Sets at Velocity Associated With max

2005 ◽  
Vol 30 (5) ◽  
pp. 543-553 ◽  
Author(s):  
Sebastien Libicz ◽  
Belle Roels ◽  
Gregoire P. Millet
Keyword(s):  
Oxygen Consumption ◽  
Maximal Oxygen Consumption ◽  
Interval Training ◽  
Swimming Velocity ◽  
Time Duration ◽  
Incremental Test ◽  
Large Variability ◽  
Equal Time ◽  
Physiological Adaptations ◽  
The Times

While the physiological adaptations following endurance training are relatively well understood, in swimming there is a dearth of knowledge regarding the metabolic responses to interval training (IT). The hypothesis tested predicted that two different endurance swimming IT sets would induce differences in the total time the subjects swam at a high percentage of maximal oxygen consumption [Formula: see text]. Ten trained triathletes underwent an incremental test to exhaustion in swimming so that the swimming velocity associated with [Formula: see text][Formula: see text] could be determined. This was followed by a maximal 400-m test and two intermittent sets at [Formula: see text] (a) 16 × 50 m with 15-s rest (IT50); (b) 8 × 100 m with 30-s rest (IT100). The times sustained above 95% [Formula: see text] (68.50 ± 62.69 vs. 145.01 ± 165.91 sec) and 95% HRmax (146.67 ± 131.99 vs. 169.78 ± 203.45 sec, p = 0.54) did not differ between IT50 and IT100 (values are mean ± SD). In conclusion, swimming IT sets of equal time duration at [Formula: see text] but of differing work-interval durations led to slightly different [Formula: see text] and HR responses. The time spent above 95% of [Formula: see text]max was twice as long in IT100 as in IT50, and a large variability between mean [Formula: see text] and HR values was also observed. Key words: interval training, maximal oxygen consumption, triathletes

scholarly journals Mood and Global Symptom Changes among Psychotherapy Clients with Depressive Personality

2012 ◽  
Vol 2012 ◽  
pp. 1-12
Author(s):  
Rachel E. Maddux ◽  
Lars-Gunnar Lundh
Keyword(s):  
Repeated Measures ◽  
Mixed Model ◽  
Psychological Symptoms ◽  
Self Report ◽  
Treatment Results ◽  
Repeated Measures Analysis ◽  
Depressive Personality ◽  
Symptom Changes ◽  
Psychotherapy Clients ◽  
Over Time

The present study assessed the rate of depressive personality (DP), as measured by the self-report instrument depressive personality disorder inventory (DPDI), among 159 clients entering psychotherapy at an outpatient university clinic. The presenting clinical profile was evaluated for those with and without DP, including levels of depressed mood, other psychological symptoms, and global severity of psychopathology. Clients were followed naturalistically over the course of therapy, up to 40 weeks, and reassessed on these variables again after treatment. Results indicated that 44 percent of the sample qualified for DP prior to treatment, and these individuals had a comparatively more severe and complex presenting disposition than those without DP. Mixed-model repeated-measures analysis of variance was used to examine between-groups changes on mood and global severity over time, with those with DP demonstrating larger reductions on both outcome variables, although still showing more symptoms after treatment, than those without DP. Only eleven percent of the sample continued to endorse DP following treatment. These findings suggest that in routine clinical situations, psychotherapy may benefit individuals with DP.

Physiological and Metabolic Responses to Exercise on Treadmill, Elliptical Trainer, and Stepper: Practical Implications for Training

2020 ◽  
pp. 1-8
Author(s):  
Andrew N. Bosch ◽  
Kirsten C. Flanagan ◽  
Maaike M. Eken ◽  
Adrian Withers ◽  
Jana Burger ◽  
...  
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Energy Expenditure ◽  
Physiological Responses ◽  
Maximal Oxygen Consumption ◽  
Metabolic Responses ◽  
Physiological Measures ◽  
Fuel Utilization ◽  
Trained Runners ◽  
Practical Implications

Elliptical trainers and steppers are proposed as useful exercise modalities in the rehabilitation of injured runners due to the reduced stress on muscles and joints when compared to running. This study compared the physiological responses to submaximal running (treadmill) with exercise on the elliptical trainer and stepper devices at three submaximal but identical workloads. Authors had 18 trained runners (male/female: N = 9/9, age: mean ± SD = 23 ± 3 years) complete randomized maximal oxygen consumption tests on all three modalities. Submaximal tests of 3 min were performed at 60%, 70%, and 80% of peak workload individually established for each modality. Breath-by-breath oxygen consumption, heart rate, fuel utilization, and energy expenditure were determined. The value of maximal oxygen consumption was not different between treadmill, elliptical, and stepper (49.3 ± 5.3, 48.0 ± 6.6, and 46.7 ± 6.2 ml·min−1·kg−1, respectively). Both physiological measures (oxygen consumption and heart rate) as well as carbohydrate and fat oxidation differed significantly between the different exercise intensities (60%, 70%, and 80%) but did not differ between the treadmill, elliptical trainer, and stepper. Therefore, the elliptical trainer and stepper are suitable substitutes for running during periods when a reduced running load is required, such as during rehabilitation from running-induced injury.

Transdermal delivery of carnosine into equine skeletal muscle

2021 ◽  
pp. 1-6
Author(s):  
B.P. Dieter ◽  
C.J. Macias ◽  
T.J. Sharpe ◽  
B. Roberts ◽  
M. Wille ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Transdermal Delivery ◽  
Repeated Measures ◽  
Muscle Metabolism ◽  
Enzyme Linked Immunosorbent Assay ◽  
Time To Exhaustion ◽  
Thoroughbred Racehorses ◽  
Repeated Measures Analysis ◽  
Main Effect ◽  
Main Effects

The dipeptide carnosine consists of β-alanine and L-histidine. It plays a major role in skeletal muscle metabolism, especially as an intracellular buffer and antioxidant. Increasing intramuscular carnosine has been shown to improve recovery from exercise and increase anaerobic threshold and time-to-exhaustion. Dietary supplementation with carnosine does not effectively increase intramuscular carnosine due to the presence of carnosinase in the blood. However, an effective transdermal delivery process could expediently increase intramuscular concentrations of carnosine. This study’s objective was to examine the efficacy of a transdermal system for delivering carnosine into the skeletal muscle of horses, using a randomised, placebo controlled, crossover study. Carnosine plus a proprietary transdermal delivery agent or the agent alone (placebo) were applied to the middle gluteal muscles of 10 Thoroughbred racehorses, and muscle biopsies were taken before and 30, 60, and 120 min after application. Muscle carnosine concentration was measured using an enzyme-linked immunosorbent assay. A two-way repeated measures analysis of variance was used to test for the main effects of time and treatment (placebo or carnosine) as well as an interaction between time and treatment. Independent F-tests examined the change in intramuscular carnosine levels from baseline to each time point (30, 60, and 120 min). There was a significant main effect of treatment (P=0.004), no significant main effect for time (P=0.18), and a non-significant interaction of treatment with time (P=0.08). Mean intramuscular carnosine concentrations increased from baseline to 120 min. Compared to concentrations following placebo application, carnosine was greater by ~35% at 30 min (P=0.002) and ~46% after 60 min (P=0.044), but not at 120 min (P=0.20). The results indicated that intramuscular carnosine can be increased using a transdermal delivery system within 60 min of application which could have important implications for the health of horses, and their capacity to perform and recover from physical activity.

Making the Grade: An Exploration of Incline Running on a Bodyweight-Supportive Treadmill

2020 ◽  
pp. 1-5
Author(s):  
Megan Wagner ◽  
Kevin D. Dames
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Repeated Measures ◽  
Perceived Exertion ◽  
Rating Of Perceived Exertion ◽  
Treadmill Running ◽  
Metabolic Effects ◽  
Metabolic Demand ◽  
Experimental Conditions ◽  
Cross Sectional

Context: Bodyweight-supporting treadmills are popular rehabilitation tools for athletes recovering from impact-related injuries because they reduce ground reaction forces during running. However, the overall metabolic demand of a given running speed is also reduced, meaning athletes who return to competition after using such a device in rehabilitation may not be as fit as they had been prior to their injury. Objective: To explore the metabolic effects of adding incline during bodyweight-supported treadmill running. Design: Cross-sectional. Setting: Research laboratory. Participants: Fourteen apparently healthy, recreational runners (6 females and 8 males; 21 [3] y, 1.71 [0.08] m, 63.11 [6.86] kg). Interventions: The participants performed steady-state running trials on a bodyweight-supporting treadmill at 8.5 mph. The control condition was no incline and no bodyweight support. All experimental conditions were at 30% bodyweight support. The participants began the sequence of experimental conditions at 0% incline; this increased to 1%, and from there on, 2% incline increases were introduced until a 15% grade was reached. Repeated-measures analysis of variance was used to compare all bodyweight-support conditions against the control condition. Main Outcome Measures: Oxygen consumption, heart rate, and rating of perceived exertion. Results: Level running with 30% bodyweight support reduced oxygen consumption by 21.6% (P < .001) and heart rate by 12.0% (P < .001) compared with the control. Each 2% increase in incline with bodyweight support increased oxygen consumption by 6.4% and heart rate by 3.2% on average. A 7% incline elicited similar physiological measures as the unsupported, level condition. However, the perceived intensity of this incline with bodyweight support was greater than the unsupported condition (P < .001). Conclusions: Athletes can maintain training intensity while running on a bodyweight-supporting treadmill by introducing incline. Rehabilitation programs should rely on quantitative rather than qualitative data to drive exercise prescription in this modality.

Psychophysiologic responses of mechanically ventilated patients to music: a pilot study

1995 ◽  
Vol 4 (3) ◽  
pp. 233-238 ◽  
Author(s):  
LL Chlan
Keyword(s):  
Heart Rate ◽  
Respiratory Rate ◽  
Repeated Measures ◽  
Mood States ◽  
Profile Of Mood States ◽  
Music Listening ◽  
Mechanically Ventilated ◽  
Mechanically Ventilated Patients ◽  
Over Time ◽  
Ventilated Patients

BACKGROUND: Although mechanically ventilated patients experience numerous stressors, they have not been included in music therapy stress reduction and relaxation studies. OBJECTIVE: To examine selected psychophysiologic responses of mechanically ventilated patients to music. METHODS: A two-group experimental design with pretest, posttest, and repeated measures was used. Twenty mechanically ventilated patients were randomized to a music-listening group or a nonmusic (headphones only) group. Physiologic dependent measures--heart rate and rhythm, respiratory rate, systolic and diastolic blood pressure, oxygen saturation, and airway pressure--were collected at timed intervals. Psychologic data were collected before and after intervention using the Profile of Mood States. RESULTS: Using repeated measures analysis of variance, results for heart rate and respiratory rate over time and over time between groups were significant. Between-group differences were significant for respiratory rate. Significant differences were found via t test for the music group's Profile of Mood States scores. No adverse cardiovascular responses were noted for either group. CONCLUSIONS: Data indicated that music listening decreased heart rate, respiratory rate, and Profile of Mood States scores, indicating relaxation and mood improvement.

scholarly journals Effects of a 2-km Swim on Markers of Cycling Performance in Elite Age-Group Triathletes

Sports ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 82
Author(s):  
Jeffrey Rothschild ◽  
George H. Crocker
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Blood Lactate ◽  
Peak Power ◽  
Maximal Oxygen Consumption ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Cycling Performance ◽  
Age Group

The purpose of this study was to examine the effects of a 2-km swim on markers of subsequent cycling performance in well-trained, age-group triathletes. Fifteen participants (10 males, five females, 38.3 ± 8.4 years) performed two progressive cycling tests between two and ten days apart, one of which was immediately following a 2-km swim (33.7 ± 4.1 min). Cycling power at 4-mM blood lactate concentration decreased after swimming by an average of 3.8% (p = 0.03, 95% CI −7.7, 0.2%), while heart rate during submaximal cycling (220 W for males, 150 W for females) increased by an average of 4.0% (p = 0.02, 95% CI 1.7, 9.7%), compared to cycling without prior swimming. Maximal oxygen consumption decreased by an average of 4.0% (p = 0.01, 95% CI −6.5, −1.4%), and peak power decreased by an average of 4.5% (p < 0.01, 95% CI −7.3, −2.3%) after swimming, compared to cycling without prior swimming. Results from this study suggest that markers of submaximal and maximal cycling are impaired following a 2-km swim.

scholarly journals Time Course and Magnitude of Tolerance to the Ergogenic Effect of Caffeine on the Second Ventilatory Threshold

Life ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 343
Author(s):  
Carlos Ruiz-Moreno ◽  
Beatriz Lara ◽  
Jorge Gutiérrez-Hellín ◽  
Jaime González-García ◽  
Juan Del Coso
Keyword(s):  
Heart Rate ◽  
Aerobic Exercise ◽  
Body Mass ◽  
Repeated Measures ◽  
Time Course ◽  
Ventilatory Threshold ◽  
Statistical Significance ◽  
Ergogenic Effect ◽  
Double Blind ◽  
Main Effects

Pre-exercise caffeine ingestion has been shown to increase the workload at ventilatory threshold, suggesting an ergogenic effect of this stimulant on submaximal aerobic exercise. However, the time course of tolerance to the effect of caffeine on ventilatory threshold is unknown. This study aimed to determine the evolution of tolerance to the ergogenic effect of caffeine on the ventilatory threshold. Methods: Eleven participants (age 32.3 ± 4.9 yrs, height 171 ± 8 cm, body mass 66.6 ± 13.6 kg, VO2max = 48.0 ± 3.8 mL/kg/min) took part in a longitudinal, double-blind, placebo-controlled, randomized, crossover experimental design. Each participant took part in two identical treatments: in one treatment, participants ingested a capsule containing 3 mg of caffeine per kg of body mass per day (mg/kg/day) for twenty consecutive days; in the other treatment, participants ingested a capsule filled with a placebo for the same duration and frequency. During these treatments, participants performed a maximal ramp test on a cycle ergometer three times per week and the second ventilatory threshold (VT2) was assessed by using the ventilatory equivalents for oxygen and carbon dioxide. Results: A two-way ANOVA with repeated measures (substance × time) revealed statistically significant main effects of caffeine (p < 0.01) and time (p = 0.04) on the wattage obtained at VT2, although there was no interaction (p = 0.09). In comparison to the placebo, caffeine increased the workload at VT2 on days 1, 4, 6 and 15 of ingestion (p < 0.05). The size of the ergogenic effect of caffeine over the placebo on the workload at VT2 was progressively reduced with the duration of the treatment. In addition, there were main effects of caffeine (p = 0.03) and time (p = 0.16) on VO2 obtained at VT2, with no interaction (p = 0.49). Specifically, caffeine increased oxygen uptake at VT2 on days 1 and 4 (p < 0.05), with no other caffeine–placebo differences afterwards. For heart rate obtained at VT2, there was a main effect of substance (p < 0.01), while the overall effect of time (p = 0.13) and the interaction (p = 0.22) did not reach statistical significance. Heart rate at VT2 was higher with caffeine than with the placebo on days 1 and 4 (p < 0.05). The size of the effect of caffeine on VO2 and heart at VT2 tended to decline over time. Conclusion: Pre-exercise intake of 3 mg/kg/day of caffeine for twenty days enhanced the wattage obtained at VT2 during cycling ramp tests for ~15 days of ingestion, while there was a progressive attenuation of the size of the ergogenic effect of caffeine on this performance variable. Therefore, habituation to caffeine through daily ingestion may reduce the ergogenic effect of this stimulant on aerobic exercise of submaximal intensity.

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