The effect of training at the same time-of-day on the diurnal variations of technical ability and swimming performance

The aim of this study is to see whether Ramadan fasting has an effect on the diurnal variations in anaerobic power and swimming performance or not. Ten participants whose mean ± SE for age, height, body mass are 19.4 ± 1.4 years, 1.72 ± 0.1 m and 72.8 ± 6.6 kg, respectively. They are tested at 3 testing periods [i.e., one week before Ramadan (BR), the middle period of Ramadan (MPR), the end period of Ramadan (EPR)], tests are performed at 07:00 h and 17:00 h throughout every course. The test sessions were started with oral temperature and body mass measurements. Regularly doing first the Wingate test then a 25-m swim at maximal speed at each test session. During the three experimental periods, dietary intake was assessed. The result shows a significant diurnal variation of muscle power and fatigue throughout the Wingate test before Ramadan. Likewise, there is a daily rhythm in the stroke parameters and swimming performance in the mentioned period. These diurnal variations change during the month of Ramadan with a decrease in power output, swim performance, swim speed and stroke length in the evening, with no changes for the morning tests. Moreover, the diurnal variations of muscle fatigue during the three morning tests show no changes and remain the same. Whereas the three evening tests show a gradual increase towards tiredness. The results show that Ramadan may has a great effect on the circadian rhythm of muscle power and swimming performance. The time-of-day effects the anaerobic power variables during the normal days which disappear during Ramadan. Ramadan fasting effects performance in the evening; however, the morning performance tests are unchangeable during Ramadan. Additionally, Ramadan fasting has no adverse effect on energy intake, and percentages of macronutrient intake. Article visualizations:<img src="/-counters-/edu_01/0856/a.php" alt="Hit counter" />

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The circadian clock within the heart: potential influence on myocardial gene expression, metabolism, and function

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00582.2005 ◽

2006 ◽

Vol 290 (1) ◽

pp. H1-H16 ◽

Cited By ~ 142

Author(s):

Martin E. Young

Keyword(s):

Circadian Clock ◽

Potential Role ◽

Myocardial Metabolism ◽

Time Of Day ◽

Diurnal Variations ◽

Intrinsic Properties ◽

Molecular Events ◽

Transcriptional Modulators ◽

And Function ◽

Myocardial Gene Expression

It is becoming increasingly clear that the intrinsic properties of both the heart and vasculature exhibit dramatic oscillations over the course of the day. Diurnal variations in the responsiveness of the cardiovascular system to environmental stimuli are mediated by a complex interplay between extracellular (i.e., neurohumoral factors) and intracellular (i.e., circadian clock) influences. The intracellular circadian clock is composed of a series of transcriptional modulators that together allow the cell to perceive the time of day, thereby enabling preparation for an anticipated stimulus. These molecular timepieces have been characterized recently within both vascular smooth muscle cells and cardiomyocytes, giving rise to a multitude of hypotheses relating to the potential role(s) of the circadian clock as a modulator of physiological and pathophysiological cardiovascular events. For example, evidence strongly supports the hypothesis that the circadian clock within the heart modulates myocardial metabolism, which in turn facilitates anticipation of diurnal variations in workload, substrate availability, and/or the energy supply-to-demand ratio. The purpose of this review is therefore to summarize our current understanding of the molecular events governing diurnal variations in the intrinsic properties of the heart, with special emphasis on the intramyocardial circadian clock. Whether impairment of this molecular mechanism contributes toward cardiovascular disease associated with hypertension, diabetes mellitus, shift work, sleep apnea, and/or obesity will be discussed.

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Diurnal variation in aviation significant gravity-dependent and gravity-independent anthropometric parameters

Indian Journal of Aerospace Medicine ◽

10.25259/ijasm_61_2020 ◽

2021 ◽

Vol 65 ◽

pp. 5-9

Author(s):

Pooja Kumari ◽

V Raghunandan ◽

P Biswal

Keyword(s):

Diurnal Variation ◽

Time Of Day ◽

Diurnal Variations ◽

Repeated Measure ◽

Leg Length ◽

Anthropometric Parameters ◽

Erect Posture ◽

Intervertebral Disc Height ◽

The Difference ◽

Independent Parameters

Introduction: Anthropometric parameters need to be accurately measured because of their direct implications in selection of aircrew, aircrew-cockpit compatibility, and cockpit workspace design. Some of these parameters have significant diurnal variation, hence, measurement of these parameters in particular time of day becomes important. Quantification of these diurnal variations among some of the aviation significant parameters was the desired objective of the study. Material and Methods: In a prospective repeated measure design, anthropometric parameters of a total of 35 volunteers were measured in the standard defined protocol from 0800h to 1600h, at an interval of every 2h, using Institute of Aerospace Medicine (IAM) Anthropometry Platform. The data were analyzed to observe and quantify changes in diurnal variations in both gravity-dependent and gravity-independent parameters. A maximum value of 0.4 cm was taken as intraobserver variations based on the results of a pilot study. Results: There was a statistically significant decrement in the values of gravity-dependent anthropometric parameters from morning to evening; the difference being more after 1200h. Most of the gravity-independent parameters did not show any significant changes from 0800h to 1600h, except leg length, which showed a decrement overtime, the difference being statistically significant after 1200h. Conclusion: The study revealed a statistically significant variation of gravity-dependent anthropometric parameters from the baseline which could be because of the effect of erect posture on the intervertebral disc height and axial compressive loads on the spine. This became practically significant after 1200h. However, most of the gravity-independent parameters did not show any significant variations. Based on the results of this study, anthropometric measurements should be done in the morning hours preferably before 1200h.

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Diurnal Variation in Swim Performance Remains, Irrespective of Training Once or Twice Daily

International Journal of Sports Physiology and Performance ◽

10.1123/ijspp.2.2.192 ◽

2007 ◽

Vol 2 (2) ◽

pp. 192-200 ◽

Cited By ~ 10

Author(s):

Louise Martin ◽

Alan M. Nevill ◽

Kevin G. Thompson

Keyword(s):

Heart Rate ◽

Blood Lactate ◽

Swimming Performance ◽

Time Trial ◽

Time Of Day ◽

Oral Temperature ◽

Warm Up ◽

Training Groups ◽

Swim Performance

Purpose:Fast swim times in morning rounds are essential to ensure qualification in evening finals. A significant time-of-day effect in swimming performance has consistently been observed, although physical activity early in the day has been postulated to reduce this effect. The aim of this study was to compare intradaily variation in race-pace performance of swimmers routinely undertaking morning and evening training (MEG) with those routinely undertaking evening training only (EOG).Methods:Each group consisted of 8 swimmers (mean ± SD: age = 15.2 ± 1.0 and 15.4 ± 1.4 y, 200-m freestyle time 132.8 ± 8.4 and 136.3 ± 9.1 s) who completed morning and evening trials in a randomized order with 48 h in between on 2 separate occasions. Oral temperature, heart rate, and blood lactate were assessed at rest, after a warm-up, after a 150-m race-pace swim, and after a 100-m time trial. Stroke rate, stroke count, and time were recorded for each length of the 150-m and 100-m swims.Results:Both training groups recorded significantly slower morning 100-m performances (MEG = +1.7 s, EOG = +1.4 s; P < .05) along with persistently lower morning temperatures that on average were –0.47°C and –0.60°C, respectively (P < .05). No differences were found in blood-lactate, heart-rate, and stroke-count responses (P > .05). All results were found to be reproducible (P > .05).Conclusions:The long-term use of morning training does not appear to significantly reduce intradaily variation in race-pace swimming or body temperature.

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A quantitative analysis of the effects of activity and time of day on the diurnal variations of blood pressure

Journal of Chronic Diseases ◽

10.1016/0021-9681(87)90103-2 ◽

1987 ◽

Vol 40 (7) ◽

pp. 671-681 ◽

Cited By ~ 138

Author(s):

L.A. Clark ◽

L. Denby ◽

D. Pregibon ◽

G.A. Harshfield ◽

T.G. Pickering ◽

...

Keyword(s):

Blood Pressure ◽

Quantitative Analysis ◽

Time Of Day ◽

Diurnal Variations

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Physical Exercise and Time of Day: Influences on Spontaneous Motor Tempo

Perceptual and Motor Skills ◽

10.1177/003151250209500301 ◽

2002 ◽

Vol 95 (3) ◽

pp. 965-972 ◽

Cited By ~ 10

Author(s):

Fabrice Dosseville ◽

Sebastien Moussay ◽

Jacques Larue ◽

Antoine Gauthier ◽

Damien Davenne

Keyword(s):

Heart Rate ◽

Cardiac Rhythm ◽

Human Subjects ◽

Internal Clock ◽

Time Of Day ◽

Diurnal Variations ◽

Healthy Human ◽

Healthy Human Subjects ◽

Before And After ◽

Motor Rhythm

To identify whether spontaneous motor rhythm is influenced by external or internal events and whether this rhythm fluctuates across the day in parallel with heart rate diurnal variations, we simultaneously recorded heart rate and spontaneous motor rate before and after a pedaling task performed five times a day by 10 healthy human subjects. Each subject performed a Spontaneous Motor Tempo, i.e., a finger-tapping task, at a comfortable and spontaneous cadence. Pre- and postexercise Spontaneous Motor Tempo was measured as well as heart rate. There were diurnal variations in Spontaneous Motor Tempo. Both measures increased significantly after pedaling, suggesting that cardiac and spontaneous rhythms are influenced simultaneously after a moderate exercise. Also, finger-taps occurred most frequently around the initiation of the heart systole. These results suggest that a putative internal clock might regulate Spontaneous Motor Tempo and that cardiac rhythm might influence this tempo

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Sampling of digestive contents by ileal cannulation in the rabbit

Animal Science ◽

10.1017/s0003356100003214 ◽

1988 ◽

Vol 46 (1) ◽

pp. 147-151 ◽

Cited By ~ 10

Author(s):

T. Gidenne ◽

T. Bouyssou ◽

Y. Ruckebusch

Keyword(s):

Fatty Acids ◽

Crude Protein ◽

Volatile Fatty Acids ◽

Time Of Day ◽

Diurnal Variations ◽

Fresh Weight ◽

Ad Libitum ◽

Conscious Animals ◽

Digestive Contents ◽

Repeated Samples

ABSTRACTA technique is described for the collection of digestive contents with a glass T-shaped ileal cannula, in rabbits fed ad libitum. Repeated samples of ileal contents were easily obtained by gravity from conscious animals lying in a hammock for 1 h, twice a week, over a period of 2 months. Analysis of the ileal contents showed no diurnal variations in concentrations of crude protein, neutral-detergent fibre, ammonia, and total short-chain volatile fatty acids. The fresh weight output was maximal at 09.00 h and minimal at 03.00 h. The transit time of phenol sulphone phthalein between mouth and ileum was 75 (s.d. 14) min and did not vary according to the time of day when measured (08.00 to 12.00 h, 14.00 to 18.00 h, 20.00 to 24.00 h).

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The Role of Morningness and Endurance in Mood and Attention During Morning and Evening Hours

Journal of Individual Differences ◽

10.1027/1614-0001/a000189 ◽

2016 ◽

Vol 37 (2) ◽

pp. 73-80 ◽

Cited By ~ 5

Author(s):

Konrad S. Jankowski ◽

Marcin Zajenkowski

Keyword(s):

Visual Search ◽

Selective Attention ◽

Search Task ◽

Visual Search Task ◽

Time Of Day ◽

Diurnal Variations ◽

Testing Session ◽

Hedonic Tone ◽

Polish Version

Abstract. This study aimed at testing the effects of morningness-eveningness and endurance on mood and selective attention during morning and evening hours. University students (N = 80) completed the Polish version of the Morningness-Eveningness Questionnaire, the Formal Characteristics of Behaviour-Temperament Inventory, and two testing sessions scheduled during the morning and evening hours. Each testing session consisted of completing the UWIST Mood Adjective Checklist composed of three scales: energetic arousal (EA), tense arousal (TA), and hedonic tone (HT), and a computerized visual search task. Without consideration of morningness and endurance, a time-of-day effect appeared in the visual attention but not in affect: participants were more accurate and faster in the evening than in the morning. Considering morningness and endurance, neither of them influenced the selective attention but they did influence mood. Morningness influenced diurnal variations in EA and HT in such a way that from morning to evening hours, morning chronotypes showed a decrease and evening types an increase in EA and HT. During morning hours, morningness was related to higher EA and HT and lower TA, but endurance was not. During evening hours, morningness was unrelated to mood, but endurance was linked to higher EA. It is concluded that morningness and endurance impact mood differently throughout the day, with the role of morningness decreasing and the role of endurance increasing as the day progresses.

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Effectiveness of Reverse vs. Traditional Linear Training Periodization in Triathlon

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph16152807 ◽

2019 ◽

Vol 16 (15) ◽

pp. 2807 ◽

Cited By ~ 8

Author(s):

Vicente Javier Clemente-Suárez ◽

Domingo Jesús Ramos-Campo

Keyword(s):

Body Composition ◽

Swimming Performance ◽

Autonomic Modulation ◽

Jump Performance ◽

Amateur Athletes ◽

Physiological Variables ◽

Technical Ability ◽

Before And After ◽

Training Control ◽

Aerobic And Anaerobic

The present research aimed to analyze the modification in performance, body composition, and autonomic modulation of reverse and traditional linear training periodization in amateur triathletes. We analyzed running and swimming performance, strength manifestation, body composition, and autonomic modulation before and after a traditional linear training periodization (four weeks of volume-based training plus four weeks of intensity-based training plus two-week tapering), a reverse linear training periodization (four weeks of intensity-based training plus four weeks of volume-based training plus two-week tapering), and a free training control physical active group (10-week free training) in 32 amateur athletes. Independently of the periodization model, the combination of two four-week mesocycles followed by a two-week taper is an efficiency strategy to avoid overreaching, obtaining an increase in parasympathetic modulation. Moreover, both types of training periodization proposed in this study do not modified body composition of amateur triathletes. Also, compared with traditional periodization, reverse periodization efficiently improves horizontal jump performance. Finally, reverse and traditional periodization were an effective strategy to improve running biomechanical, performance, and physiological variables, as well as efficient periodization strategies to improve swimming technical ability, aerobic, and anaerobic swimming performance.

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