Doses of Coffee and Blood Pressure Response Post-exercise
Condition: Post-Exercise Hypotension; Hypertension
MeSH terms: Post-Exercise Hypotension; Hypotension
Study type: Interventional

Summary: 
      Introduction: reduction of blood pressure after physical exercise is called post exercise
      hypotension (PEH). However, previous studies demonstrate that ingestion of caffeine
      equivalent to three tea-cup of coffee abolishes this phenomenon. Objective: evaluate the
      influence of different doses of coffee in PEH. Methods: eleven hypertensive performed four
      experimental sessions of aerobic exercise in cycle ergometer (40 minutes of duration,
      intensity between 60% and 80% of maximum heart rate) succeeds for the ingestion of one
      (CAF-1), two (CAF-2), three (CAF-3) doses of caffeinated coffee (144 mg/dose), or three doses
      of decaffeinated coffee (DESC). Blood pressure was measured in rest and during 120 minutes of
      recovery post exercise, each 10 minutes.
    

Detailed description: 
      Volunteers: participated 12 volunteers diagnosed as hypertensive, both gender (three men), 40
      to 55 years old, overweight and practitioners of aerobic exercise (walk) at least three
      months. They were treated with anti-hypertensive medication of class beta-adrenergic receptor
      blockers, thiazides and enzyme convertor of angiotensin inhibitors, and showing systolic and
      diastolic pressoric values controlled and habituated to coffee consumption. Would be excluded
      from the study volunteers who presented migraine or other withdrawal symptoms due to a
      washout to be carried out for coffee and other caffeinated foods. The volunteers participated
      of this study for average one month. This study was previously approved by Ethic Committee in
      Search with Humans at Hospital Lauro Wanderley, at Federal University of Paraiba, under
      protocol 21/2011. All volunteers was previously clarified about the experimental procedures,
      and they signed the written informed consent according resolution 466/12 at Health National
      Council (Brazil).

      Design of Study: the study was experimental, randomized and double-blind. Before the
      experimental sessions the volunteers were instructed to avoid caffeinated foods during 48
      hours. They performed four experimental sessions with the practice of aerobic exercise,
      succeed for the ingestion of caffeinated or decaffeinated coffee, according to following
      protocols: 1) one dose of 150 ml of coffee (144 mg of caffeine) ingested 10 minutes
      post-exercise (CAF-1); 2- two doses of 150 ml of coffee (2x144 mg of caffeine) ingested 10
      and 20 minutes post-exercise (CAF-2); three doses of 150ml of coffee (3x 144 mg of caffeine)
      ingested 10, 20 and 30 minutes post-exercise (CAF-3); 4- three doses of 150 ml of
      decaffeinated coffee (108 mg of caffeine) ingested 10, 20 and 30 minutes post-exercise
      (DESC). The order of realization experimental sessions was determined randomly through the
      site www.randomizer.org. They remained seated during 120 minutes after exercise. Blood
      pressure was evaluated in rest, and during 120 minutes of post-exercise recovery, each 10
      minutes.

      Preparation and Ingestion of coffee: was utilized one caffeinated and decaffeinated coffee
      (São Braz, Cabedelo, Brazil) with one same serial number. Caffeinated and decaffeinated
      coffee had 1,2% and 0,3% of caffeine, respectively, in your composition. The method adopted
      to the preparation of caffeinated or decaffeinated coffee was previously utilized for Nóbrega
      et al. (15). Were prepared with addition of 40g coffee powder to each 500 ml of heated water
      during five minutes, limited by beginning of boil. Thus, the volume of 500 ml of coffee had
      one concentration of 480 mg of caffeine. Considering each tea-cup ingested had one volume of
      150 ml, so one, two and three tea-cups with coffee had respectively 144 mg, 288 mg and 432 mg
      of caffeine. Three tea-cups of decaffeinated coffee were 108 mg of caffeine. The doses of
      caffeinated or decaffeinated coffee were sweetened with sugar (Alegre, Mamanguape, Brazil).
      The coffee was strained with filters paper (Mellita®, Minden, Alemanha). To ensure the
      accuracy of volume intake by volunteers at all time was utilized one dosing tea-cup
      previously calibrated to volume of one tea-cup (150 ml). The intake coffee was performed on
      first 30 minutes of period recovery, each 10 minutes. During moment of ingestion, volunteers
      stay seated and was stipulated a deadline of five minutes to intake the coffee.

      Protocol of Physical Exercise: volunteers performed four experimental sessions with aerobic
      exercise on a stationary bicycle (Perform V3, Movement®, Pompeia, Sao Paulo), lasting 40
      minutes, intensity between 60 and 80% of maximum heart rate (MHR). To estimate of MHR was
      utilized the equation proposed by Bruce et al. (16). To the prescription of target zone for
      exercise was adopted the protocol proposed by Karvonen et al. (17). The heart rate of rest
      and during the exercise was evaluated utilizing by cardiofrequencymeter (RS800CX, Polar
      Electro® Oy, Kempele, Finland)

      Measures of Blood Pressure: after the volunteers arrived on laboratory, they were oriented to
      stay in rest seated during 10 minutes to measures of blood pressure on end of this period.
      Others measures were realized during the 120 minutes of post-exercise recovery, each
      10minutes. The first 30 minutes of post-exercise recovery the measures were always performed
      one minute before coffee administration. The blood pressure was measured by auscultatory
      method, following the protocol proposed by VI Brazilian Guidelines of Arterial Hypertension
      (18). For this, was utilized one sphygmomanometer (Missouri, Embu, Brasil), previously
      calibrated against one mercury column and one stethoscope (Missouri, Embu, Brasil).

      Statistical Analysis: all the data are presented as mean±standard-error of mean. All
      variables were tested for normal distribution using Shapiro-Wilk and Levene tests. For the
      comparisons of age, body mass index, heart rate of rest, systolic and diastolic blood
      pressure of rest between the experimental sessions was utilized one-way ANOVA. For the
      comparisons of systolic and diastolic post-exercise between the experimental sessions of
      study was realized two-way ANOVA plus Bonferroni test post hoc. P value small than 0,05 was
      considered statically significant.
    

Intervention name(s): CAF-1; CAF-2; CAF-3; DESC
Intervention type(s): Other; Other; Other; Other
Intervention description(s): In this intervention the volunteers ingested one dose of caffeinated coffee containing 144 mg of caffeine; In this intervention the volunteers ingested two doses of caffeinated coffee containing 288 mg of caffeine; In this intervention the volunteers ingested three doses of caffeinated coffee containing 432mg of caffeine; In this intervention the volunteers ingested one dose of decaffeinated coffee containing 108 mg of caffeine
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Double (Participant, Investigator)