5 Biggs et all 2017 – documents brain anoxia

Original research

Effects of simulated altitude on maximal oxygen uptake and inspiratory fitness

NICOLE C. BIGGS*, BENJAMIN S. ENGLAND*, NICOLE J. TURCOTTE*, MELISSA R. COOK

, and ALYNE L. WILLIAMS

Division of health human performance, exercise science department, indiana wesleyan university, marion, IN, USA

*denotes undergraduate,

Denotes professional author

ABSTRACT international journal of exercise science 10(1): 128-136, 2017

Aerobic exercise at altitude has shown an increase in maximal oxygen uptake. Similar effects have been replicated by way of simulated altitude training, which have influenced various advances in the field of exercise science.


Elevation training masks© (ETM) claim to stimulate cardiorespiratory fitness improvements similar to training at altitude, however, there is little research to support this claim.Brain anoxia the purpose of this study was to research the effect that a hypoxia-inducing mask would have on cardiorespiratory fitness and pulmonary function through the use of a high intensity interval training (HIIT) running program. Seventeen subjects were randomized into either the control group, without the mask, or experimental group, with the mask, and participated in a 6-week HIIT protocol of 4 sessions per week. Each session included a warm up, followed by intervals of running at 80% of their heart rate reserve (HRR) for 90 seconds and followed by 3 minutes of active rest at 50-60% of HRR. A total of 6 intervals were completed per session. Within subjects, there was a significant increase in predicted VO

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Max (F(1,17)=7.376, P .05), or between the two groups (F(1, 17)= 3.724, p= .073). Similar to the VO

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Max results, forced vital capacity demonstrated a significant increase within subjects (F(1, 17)=6.201, p.05), but there was no significant difference between the control and experimental groups (F(1,17)=3.562, p= .079). Although the between groups data was not significant, there was a greater increase in the experimental group wearing the ETM compared to the control group not wearing the mask for all 3 variables. Data suggest that HIIT training can be a viable method of improving VO

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Max and pulmonary function however, training masks such as the ETM may not lead to greater overall improvements.Brain anoxia

KEY WORDS: VO

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Max, functional lung capacity, forced inspiratory vital capacity, forced vital capacity, high intensity interval training, elevation training masks, normobaric hypoxia

INTRODUCTION cardiorespiratory fitness is defined by the ability of the body to process oxygen, distribute it to the body systems efficiently and maintain exercise intensity (4). Maximal oxygen uptake (VO

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Max) is the amount of oxygen used in the body, per kilogram of body weight per minute (4). Searching for new ways to improve the body’s ability to utilize the uptake of oxygen is a large facet of exercise science. Exercising aerobically at altitude has been proven to increase VO

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Max, as well as generate many other physiological adaptations, including ventilatory adaptations, such as increasing forced vital capacity (FVC) and forced inspiratory vital capacity (FIVC) (2, 5, 19).Brain anoxia FVC is the amount of air that can be forcefully blown out after full inspiration. FIVC is a forceful lung inspiration that was preceded by maximal lung expiration. One advancement in the field of exercise science, simulated altitude training, has worked to generate similar effects to training at altitude. One method of simulating altitude is to induce a normobaric hypoxic condition, or minimize the amount of air allowed to be consumed by an individual (15). In previous years, the equipment used to induce hypoxia has been expensive, however, various companies have begun to mass produce these pieces of equipment known to induce hypoxic conditions. The mass production of these devices have made it easier for the general public to purchase and obtain this specific equipment.Brain anoxia however, though the cost is relatively inexpensive in comparison to some products, such as a hypo-barometric chambers, the question has then been raised, “are they really effective?” regardless of company’s claims, or the cost of these devices, the effectiveness of these specific devices to improve aerobic capacity have not been widely peer reviewed. The purpose of this study was to investigate the effect that one specific, hypoxia inducing mask would have on cardiorespiratory fitness of both men and women. This study investigated elevation training masks© (ETM) (training mask, cadillac, MI) on its ability to alter VO

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Max and pulmonary function, through the addition of high intensity interval training (HIIT) while running.Brain anoxia HIIT training programs have been shown to improve aerobic capacity regardless of gender or training level (6, 18). The HIIT protocol selected has demonstrated to alter VO

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Max, and was used in the study so that both groups would potentially see altered cardiorespiratory fitness, as well as pulmonary changes (23). The hypothesis of the study was the experimental group wearing the ETM would see greater changes in cardiorespiratory fitness and improved pulmonary changes compared to a control group. METHODS participants the study was conducted using 21 indiana wesleyan university students who volunteered to participate in this 6-week study. Seventeen (ages 18-26 years, mean=21.2 years, SD=1.7 years) of the 21 subjects completed the study.Brain anoxia each subject was randomly assigned into either the

Int J exerc sci 10(1): 128-136, 2017 international journal of exercise science http://www.Intjexersci.Com 129 control (n=8) or experimental group (n=9) using a microsoft excel© filter function (microsoft, redmond, WA). Subjects varied in gender (males=12, females=5), and were moderately trained individuals who reported regularly meeting ACSM guidelines for cardiorespiratory exercise. Subjects maintained their normal cardiorespiratory exercise, in addition to completion of the 6-week protocol. Upon completion of a physical activity readiness questionnaire (par-Q) and informed consent (approved by the human subjects review board at indiana wesleyan university), subjects qualified to participate in the study.Brain anoxia all documentation and participant information was kept secure via passcodes on a single laptop and locked in a cabinet. Protocol the week prior to the 6-week protocol, subjects were evaluated for initial resting heart rate by way of manual palpation of the radial artery for 15 seconds, resting blood pressure via a sphygmomanometer (medco, tonawanda, NY) and stethoscope (marshall, tonawanda, NY), submaximal oxygen uptake (VO

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), FVC, and FIVC. Heart rate, blood pressure, FVC, and FIVC were measured while each subject was in an upright, seated position. Resting heart rate and maximal heart rate (hrmax) (206.9 – (age * 0.67)) were used to calculate heart rate reserve (HRR) (1). Blood pressure was monitored for safety precautions during submaximal testing.Brain anoxia FVC and FIVC were collected using the FVC function on the spirometer (medical international research (MIR) inc., waukesha, WI). A treadmill (matrix, cottage grove, WI) single-stage model submaximal test was used to estimate VO

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Max (8). Submaximal tests are an effective technique for estimating maximal oxygen uptake in situations with limited time or resources (18). In this study, a single-stage jogging treadmill test validated for use in younger adults was used to estimate VO

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Max (8). Following a brief warm-up, subjects were asked to jog at a comfortable, self-selected pace (4.3-7.5 mph for men; 4.3-6.5 mph for women) for 3 minutes. The subject’s heart rate was recorded using a heart rate monitor (chest strap and watches) (polar electro inc., lake success, NY).Brain anoxia the subject had to achieve a minimum heart rate of 130 beats per minute (bpm) but could not exceed 180 bpm. The subject’s heart rate was then entered into an equation to estimate VO

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Max. (VO

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Max – 54.078 – 0.1938*(body weight in kg) + 4.47*(speed in mph) – 0.1453*(HR in bpm) + 7.062*(gender: female=0; male=1) (8). These initial values were recorded and were used to compare the effects of training 6-weeks later. The 6-week study consisted of each subject performing the same HIIT running protocol 4-days per week on an indoor track. Subjects completed their 4-workouts monday through thursday, and were able to make-up a day on sunday if they had conflicts during the week. A specific HIIT protocol (24) that had shown to have an increase in overall VO

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Was used, however the protocol was modified from 90% of VO

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Max to 80% of HRR. This was done to allow subjects to use a heart rate monitor to determine their own intensity during each session. Subjects were required to maintain 80% of their HRR (±5 bpm) for 90-seconds followed by a 3-minute active rest period. During the rest period subjects had to maintain 50-60% of the HRR. A total of 6 intervals of 90-second bursts followed by 3 minute rest periods, concluded one HIIT protocol. Subjects completed 4-HIIT protocols for a duration 6-weeks always including a 5-10 minute jogging warm-up and cool-down. The subjects were split into two groups randomly using the microsoft excel© filter function. The first group was the control group (non-ETM), which

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Int J exerc sci 10(1): 128-136, 2017 international journal of exercise science http://www.Intjexersci.Com 130 completed the same HIIT protocol as the experimental group. The second group was the experimental group (with ETM), who wore an ETM for the duration of the 6-week HIIT training protocol. The mask valves were set to simulate 9,000 feet at altitude. The mask can be changed to simulate altitude ranging from 3,000 feet to 24,000 feet. Previous research has found that training at altitudes of 2,000-3,000 meters (7,000 – 10,000 feet) show increased physiological adaptations (7). Post-testing protocols were conducted the same as pre-testing. All subjects went through identical testing where resting heart rate, resting blood pressure, submaximal VO

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, FVC, and FIVC were measured and collected. Prediction equations were once again used to predict VO

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Max. Once data was collected, data was analyzed for differences between pre- to post-testing values. Statistical analysis the researchers wanted to evaluate the effectiveness of the HIIT program as well as the effect of the ETM mask. Therefore, a 2×2 mixed-design ANOVA series using the software program statistical package for the social sciences© (SPSS) was used. This statistical method allows for comparison both within subjects (pre-test vs. Post-test) and between subjects (control vs. Experimental) as compared to a repeated measures which evaluates only the pre-test vs. Post-test measurements.Brain anoxia this test compared predicted VO

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Max, FIVC, and FVC values within subjects from pre-testing to post-testing as well as between the control and experimental group. A p-value, in this study, of 0.05 is considered significant. Additionally, a large effect size is considered to be above 0.14. RESULTS A 2×2 between groups ANOVA was used to analyze the change in predicted VO

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Max between the control group and experimental group from pre- to post-testing. There was no significant difference between the control group and experimental group (F(1,17)= 3.669, p= 0.075, partial ETA squared= 0.197) (see figure 1 and table 1).

Table 1. Means (±SD) for between subjects comparison. Group pre-test post-test p value VO

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Max (ml/kg/min) non-ETM with ETM 45.23± 4.05 48.05± 4.94 46.26± 2.87 51.19± 5.33 0.075 FIVC (L/sec) non-ETM with ETM 3.38± 1.26 4.36± 1.26 3.60± 1.01 4.68± 1.13 0.073 FVC (L) non-ETM with ETM 3.70± 1.27 4.53± 0.97 3.98± 0.87 5.00± 1.08 0.079

A 2×2 between groups ANOVA was also used to look at the pre- to post-testing values of FIVC between the control and experimental groups. There was no significant difference between the 2 groups (F(1, 17)= 3.724, p= .073, partial ETA squared= .199) (see figure 2 and table 1).