M. W. Flatz, E. Punter, W. Schobersberger, E. Humpeler Physiological Effects of a Vacation with Physical Activity at Altitude

Markus W. Flatz, Evelyn Punter, Wolfgang Schobersberger, Egon Humpeler

Physiological Effects of a Vacation with Physical Activity at Altitude – Preliminary Data from a Project Concerning the Austrian Moderate Altitude Studies (AMAS)

SUMMARY

This study presents measurements and analysis from a real time vacation at moderate altitude (1450 m) including customized and guided physical activities. This program was based on the Austrian Moderate Altitude Studies (AMAS). Hence, the aim here was to compare this data to the results of AMAS. We tested 28 subjects (male and female) mean age (SD) 53.5 (13.3) years, mean height 1.76 (0.09) m and mean weight 79.2 (16.5) kg, and compared basic resting and exercising measurements from PRE (after 1st overnight) to POST (10th day of the vacation). At rest we conducted body impedance analysis (BIA), heart rate (HR), blood pressure (BP) and percutan pulsoximetry (SpO2) measurements. Exercise tests included an indoor step test (HR, SpO2, BORG perceived exertion scale) and a defined test hiking trail with a flat and a following steep part aiming for similar hiking time with comparable power output (time, HR, SpO2, BORG). The results showed a reduction in body weight solely due to a loss of body fat and unchanged fluid balance. Also, systolic blood pressure decreased significantly. Both exercise tests (indoor step test and defined hiking trail) revealed a decreased heart rate response, increased oxygen saturation and decreased BORG rating: over all an improved exercise tolerance. These results showed positive effects from a real time vacation with guided physical activities at moderate altitude on body composition, blood pressure and exercise tolerance. This is consistent with the results of AMAS. Keywords: exercise tolerance, health tourism, Welltain®

ZUSAMMENFASSUNG

Wir erhoben und analysierten Daten eines praktisch durchgeführten Urlaubs in mittlerer Höhe (1450 m) mit adäquater und betreuter körperlicher Aktivität. Dieses Programm basiert auf den Österreichischen Höhenstudien (Austrian Moderate Altitude Studies - AMAS). Ziel war es daher auch, die Ergebnisse dieses real durchgeführten Urlaubs (Welltain®) mit denen der AMAS-Studien zu vergleichen. Die Daten von 28 Personen (Frauen und Männer), mit den Mittelwerten (Standardabweichung) für Alter 53.5 (13.3) Jahre, Größe 1.76 (0.09) m und Gewicht 79.2 (16.5) kg wurden analysiert. Einfache Messungen während Ruhebedingungen sowie während moderater körperlicher Belastung wurden am Tag nach der ersten Übernachtung und am zehnten Tag des Urlaubs gemessen und verglichen. Unter standardisierten Ruhebedingungen wurde eine Körperzusammensetzungsmessung (BIA), die Herzfrequenz (HR), der Blutdruck (BP) und perkutan die Sauerstoffsättigung (SpO2) gemessen. Mittels eines standardisierten Stufentests (HR, SpO2, BORG Skala für subjektives Beanspruchungsempfinden) und einer definierten Testwanderstrecke bestehend aus einem flachen Teilstück und einem anschließenden Anstieg wurden Belastungsmessungen durchgeführt (Zeit, HR, SpO2, BORG). Die Ergebnisse zeigten eine Reduktion des Körpergewichts, hauptsächlich aufgrund der Abnahme des Körperfettanteiles und einen unveränderten Flüssigkeitsstatus. Weiters kam es zu einer Abnahme des systolischen Blutdrucks. Für beide Belastungstests (Stufentest und Testwanderstrecke) zeigten sich eine Abnahme der Belastungsherzfrequenz, eine verbesserte Sauerstoffsättigung und eine verminderte subjektive Beanspruchung, zusammengefasst eine verbesserte Belastungstoleranz. Diese Ergebnisse zeigen positive Effekte eines real durchgeführten Urlaubs mit betreuten Aktiveinheiten in mittlerer Höhe hinsichtlich der Körperzusammensetzung, des Blutdrucks und der Belastungstoleranz. Diese Ergebnisse stimmen mit jenen der AMAS Studien überein und bestätigen die positiven Effekte eines betreuten Aktivurlaubs in mittlere Höhenlage. Schlüsselwörter: Belastungstoleranz, Gesundheitstourismus, Welltain®

INTRODUCTION

The Austrian Moderate Altitude Study (pilot study AMAS and AMAS I) was conducted to research the safety aspects for people with metabolic syndrome and the effects of a sojourn including appropriate physical activity at moderate altitudes of 1700m (sleeping altitude), up to 2500 m during hikes. Furthermore, AMAS II was conducted especially to research regenerative effects during a one-week sojourn with moderate physical activity and relaxation exercises at moderate altitude (1700 m) in healthy subjects.

To date, numerous papers out of these studies are published describing different aspects (1 - 10). Based on these results the tourism project Welltain® started in 2002 with the aim to offer a unique vacation: medical and sport scientific anamnesis and tests at the beginning and at the end of the vacation, an appropriate and well adjusted exercise schedule, conducted and guided by sport scientific experts and completed by regeneration exercises and massages to fulfil the needs of the guests for their health benefits. The aim of this preliminary data was to analyse the data from the pre- and post-tests of this real time vacation to gain information about the effects of such an individually styled program and to compare them to the AMAS data.

METHODS

All measurements were obtained at an altitude of 1450 m, the sleeping altitude during the vacation was 1450 m – 1700 m, whereas the usual living altitude of the subjects included was between sea level and 800 m. The pre-tests took place in the morning after the first overnight, 2 hours or more after a light breakfast. The post-tests were taken at the same daytime and nutritional status as the pre-tests, on day 10 of the vacation. During the vacation there were no restrictions regarding food intake, hence, no control of that. Drinking water was suggested often during the hikes and beyond as a part of the information the guests received concerning the needs for exercise, especially at altitude. The exercise program for every guest was customized. 28 healthy men and women, mean age 53.5 ± 13.3 years (range 38 – 79yrs.), mean height 1.76 ± 0.09 m, mean weight 79.2 ± 16.5 kg, and mean body mass index (BMI) 25.5 ± 4.0 kg/m2 were included in this study. All of them underwent medical observation by a physician prior to the program and were declared as fit for appropriate exercises and treatments.

Rest At rest we made body composition analysis (BIA, Biosign Inbody 3.0, Korea), and measured heart rate (HR, Polar S 810i, Finland), blood pressure (BP) and percutan pulsoximetry (SpO2, Mini Corr Pulsoximeter, Smith Industries Medical Systems).

Exercise We used a modified Harvard step test with individual step settings as an indoor exercise test. Step height and the frequency of the steps were set to an individual level for each subject to guarantee a moderate intensity. Considering a steady level of condition, we measured heart rate (HR), SpO2 and BORG-rate of perceived exertion (14) between minute 3 and 4 during the test.

Another exercise test took place under field conditions, using a designated hiking trail with a flat part and a following steep part. Again, HR, and in the steep part, SpO2 and BORG ratings were obtained. The aim for both exercise tests (indoor and field test) was to generate the same power output for pre- and post-testing. Identical step height and frequency for the indoor test and identical hiking velocity for the field test were applied through the sport scientific experts (exercise physiologists) who also guided the guests throughout their vacation, supporting them with knowledge and information about exercise, altitude, a healthy life-style and individual concepts for their every-day use after the vacation.

Statistics We used a paired students t-test (two tailed) to compare pre- vs. post-test data, assuming normal distribution of this biomedical data. A p value ≤ 0.05 was defined as statistically significant. Data are shown as means and standard deviation in parenthesis (SD).

RESULTS

All participants completed the tests and the exercise program without any complications and left motivated for their ever-day lives. Results are also shown in table 1. The exercise program of every guest was customized. Overall about 3 hrs endurance exercises (hiking, Nordic walking, biking) per day at an intensity of 60-80% HRmax, and BORG ratings from 10 - 15, and additional exercises (strength training, gymnastics, regeneration training, 4 - 5 times in 12 days) were performed.

Rest The BIA showed a significant loss of body weight (-0.8 kg from 79.2 (16.5) kg to 78.4 (15.9) kg, p=0.01), accompanied by a change in BMI (25.5 (4.0) kg/m2 vs. 25.2 (3.9) kg/m2, p=0.01). This was solely due to the loss of body fat (- 0.5 kg from 19.8 (11.9) kg to 19.3 (6.8) kg, p=0.06). Total body fluid, intra- and extra-cellular fluids remained unchanged. There was no change in resting HR and SpO2 increased borderline (94.6 (1.7) % vs. 95.1 (1.8) %, p=0.06). Even though we only were able to include 4 subjects, systolic blood pressure (SBP) decreased (133.5 (2.9) mmHg vs. 125.3 (4.5) mmHg, p=0.05, n=4 !), and diastolic blood pressure (DBP) remained statistically unchanged (84.0 (7.3) mmHg vs. 78.0 (3.9) mmHg, p=0.2, n=4).

Exercise - Step Test The indoor step test revealed a decreased HR (120 (20) min-1 vs. 114 (17) min-1 ,

p=0.001), an unchanged SpO2 (93.3 (2.5) vs. 93.8 (2.5), p=0.15), and a decreased BORG-rating (12.1 (1.7) vs. 10.9 (1.9), p=0.004).

Exercise - Test Hiking Trail During the flat and the steep part of the test hiking trail we measured an unchanged hiking time (935 (252) seconds vs. 928 (238) s, p=0.8 and 428 (187) s vs. 446 (201) s, p=0.2 respectively), and a decreased HR response (111 (10) min-1 vs. 104 (11) min-1 , p<0.001 for the flat part, and 132 (12) min-1 vs. 121 (16) min-1, p<0.001 for the incline respectively). SpO2 increased during the steep part (91.3 (3.2) % vs. 92.4 (2.7) %, p=0.005) whereas the BORG-rating decreased (13.7 (1.5) vs. 12.3 (1.8), p=0.001).

Table 1:

Results from resting and exercising measurements on the 1st morning after arrival at altitude (1450 m) (PRE) and on the 10th day of the vacation (POST). p value alike or lower than 0.05 are defined as statistically significant. Data shown as means (standard deviation)

REST

EXERCISE BIA

CV

STEP

HIKE PRE (1st POST (10th p value (n=28) morning after day at arrival at altitude) altitude) Weight [kg] 79.2 (16.5) 78.4 (15.9) 0.01 BMI [kg/m2] 25.5 (4.0) 25.2 (3.9) 0.01 Total body water [l] 43.8 (9.4) 43.6 (9.2) 0.1 Intracellular water [l] 28.3 (6.2) 28.2 (6.2) 0.22 Extra cellular water [l] 15.3 (3.7) 15.2 (3.7) 0.57 Fat mass [kg] 19.8 (11.9) 19.3 (6.8) 0.06 % body fat [%] 24.3 (6.5) 23.9 (6.4) 0.18 HR [min-1] 67.5 (8.8) 67.3 (9.6) 0.91 SpO2 [%] 94.6 (1.7) 95.1 (1.8) 0.06 SBP [mmHg] 133.5 (2.9) 125.3 (4.5) 0.05 * n=4 DBP [mmHg] 84.0 (7.3) 78.0 (3.9) 0.2 * n=4 HR [min-1] 120.3 (19.6) 113.7 (17.0) 0.001 SpO2 [%] 93.3 (2.5) 93.8 (2.5) 0.15 BORG rating 12.1 (1.7) 10.9 (1.9) 0.004 Time flat [sec] 934.7 (252) 928.3 (238) 0.78 HR flat [min-1] 111.4 (10.0) 103.5 (10.5) <0.001 Time steep [sec] 428.1 (187) 445.9 (201) 0.15 HR steep [min-1] 131.5 (12.0) 120.9 (15.5) <0.001 SpO2 steep [%] 91.3 (3.2) 92.4 (2.7) 0.005 BORG steep 13.7 (1.5) 12.3 (1.8) 0.001

Abbreviations: BIA (body impedance analysis), CV= Cardiovascular, BMI (body mass index), HR (heart rate), SpO2 (percutan oxygen saturation), SBP (systolic blood pressure), DBP (diastolic blood pressure).

DISCUSSION

We analysed data of 28 men and women who completed a customized vacation program at moderate altitude including physical exercise and regeneration. Initialised through the Austrian Moderate Altitude Studies (AMAS) this project was in collaboration with the tourism industry, medicine, and exercise physiological experts.

Body composition We measured a loss of body weight solely due to the loss of body fat. This weight loss corresponded with the results of the AMAS pilot study (3) and AMAS I (4). Total body fluid remained unchanged from pre to post test (2nd to 10th day at altitude). This is also confirms the results of Gunga et al. (3), and Greie et al. (4) with which Gunga et al. showed an initial fluid loss from low to moderate altitude but unchanged body fluids until day 9 at altitude (3). From our data we are not able to exclude another possible explanation for decreased body weight: the loss of appetite. Nevertheless, Gunga (3) showed that Leptin as a marker of appetite loss is not increased and is moreover expected to decline because of the physical activity. Overall we conclude that the increased caloric turnover due to appropriate physical exercise is responsible for the loss of fat and body mass.

Cardiovascular measurements at rest Because of the relatively short time period we did not expect a decreased HR at rest due to training effects. For effects on HR due to acclimatization our data are consistent with the AMAS pilot study and others at similar altitude (2000m) (2,11). SpO2 tended to increase during the 10-day period (94.6 vs. 95.1 %, p=0.06). 1450 m is too low of an altitude to prove statistical significance for this study group and study design. In contrast, other studies at higher altitudes (2000 m) found statistically significant changes. Although we were able to include BP data from 4 subjects only, we measured a decrease of systolic BP (SBP) and statistically unchanged diastolic BP (DBP). Again, this coincides with the data from the AMAS pilot study (2), and the main study, in which Greie et al. (4) showed decreased DBP as well. Even with the limited samples in our data, these findings demonstrate once more that exposure to altitude with customized physical activity has the potential to decrease SBP and DBP in a clinical relevant manner (84.0 mmHg vs. 78.0 mmHg, p=0.19, n=4). It is relevant to point out that the effects on BP seem to be independent from the altitude level since Greie et al. showed the same decrease in the control group at 200 m (4). However, it remains unproved which single factor, i.e. vacation, physical activity, or a combination of both, has most impact on the reduction of blood pressure.

Cardiovascular Measurements at Submaximal Exercise We measured a marked reduction of exercise HR response during the stay at moderate altitude for both exercise tests (indoor step test and test hiking trail). Due to unchanged hiking time from pre- to post-test, subjects had similar power output in both test hikes. These results are consistent with data from the hiking study from Burtscher et al. (11), and are evidence for a better exercise tolerance at altitude. However, because of a missing a sedentary control group we are not able to clarify if this decrease is either because of physical activity or altitude acclimatization or the combination of both. Unfortunately, we have no data concerning cardiovascular responses before and/or after the stay at altitude to support all the effects of this treatment. Reports from AMAS showed an unchanged maximal power and heart-rate response one week after the return to 600 m (2,4). The latter described an increased relative maximal power output based on decreased body-weight (4). On the contrary, Burtscher et al. (11) measured reduced HR during submaximal exercise back at 600 m (after 1 week at 2000 m). and discussed a down regulation of beta receptors and/or increased parasympathetic activity suggested from Kacimi et al. (12). A resting control group at altitude is needed to clarify the effects of physical activity and altitude acclimatization on cardiovascular changes during exercise.

SUMMARY and PREVIEW

Regarding the positive effects on body composition, blood pressure and exercise tolerance, data are consistent with the results from AMAS. However, further studies are required in order to develop guidelines for vacationers with pre-existing chronic diseases visiting moderate altitudes. Moreover, moderate hypoxia may serve as model for different aspects of human physiology and psychology. We are aware that data of the control group at 200 m published by Greie et al. (4) showed basically the same effects on cardiovascular, anthropometric and metabolic parameters, hence, showed similar benefits of a vacation, either at low or moderate altitude. To date, control groups at either altitude without physical activity are missing to detect the casualities of altitude, vacation and of course of physical activity. Therefore, it might not be a question of altitude but a question of the additional treatment. Nevertheless, safety is the main outcome in the studies with a well-designed scientific manner, as well as in an applied real-time vacation, and there are similar benefits up to 1700 m of altitude. On the other hand, latest findings concerning extra benefits from a sojourn at altitude derived from the data of AMAS II (10), in which increased levels of circulating progenitor cells were measured after a week sojourn at moderate altitude. Further topics of interest might include effects on glucose intolerance and diabetes mellitus respectively

since results from intermittent hypoxia studies showed promising results (13). Taking into account some environmental aspects, regeneration ability concerning effects of light at night, noise level and allergens, and effects of movement patterns during hiking uphill and downhill (cardiovascular, neuromuscular, metabolic and equilibrium aspects) should be focused on in further studies.

REFERENCES

(1) Schobersberger W., Greie S., Humpeler E., Mittermayr M., Fries D., Schobersberger B., Artner-Dworzak E., Hasibeder W., Klingler A., Gunga H.C. Austrian Moderate Altitude Study (AMAS 2000): erythropoietic activity and Hb-O(2) affinity during a 3-week hiking holiday at moderate altitude in persons with metabolic syndrome. High Alt Med Biol 2005 Summer;6(2):167-77.

(2)

(3) Schobersberger W., Schmid P., Lechleitner M., von Duvillard S.P., Hörtnagl H., Gunga H.C., Klingler A., Fries D., Kirsch K., Spiesberger R., Pokan R., Hofmann P., Hoppichler F., Riedmann G., Baumgartner H., Humpeler E. Austrian Moderate Altitude Study 2000 (AMAS 2000). The effects of moderate altitude (1,700 m) on cardiovascular and metabolic variables in patients with metabolic syndrome. Eur J Appl Physiol 2003 Feb;88(6):506-514.

Gunga H.C., Fries D., Humpeler E., Kirsch K., Boldt L.E., Koralewski E., Johannes B., Klingler A., Mittermayr M., Röcker L., Yaban B., Behn C., Jelkmann W., Schobersberger W. Austrian Moderate Altitude Study (AMAS 2000) - fluid shifts, erythropoiesis, and angiogenesis in patients with metabolic syndrome at moderate altitude (congruent with 1700 m). Eur J Appl Physiol 2003 Feb;88(6):497-505. Epub 2002 Nov 27.

(4) Greie S., Humpeler E., Gunga H.C., Koralewski E., Klingler A., Mittermayr M., Fries D., Lechleitner M., Hoertnagl H., Hoffmann G., Strauss-Blasche G., Schobersberger W. Improvement of metabolic syndrome markers through altitude specific hiking vacations. J Endocrinol Invest 2006 Jun;29(6):497-504.

(5)

(6)

(7)

(8) (9) (10) (11) (12) Strauss-Blasche G., Riedmann B., Schobersberger W., Ekmekcioglu C., Riedmann G., Waanders R., Fries D., Mittermayr M., Marktl W., Humpeler E. Vacation at moderate and low altitude improves perceived health in individuals with metabolic syndrome. J Travel Med 2004 Sep-Oct;11(5):300-304.

Frick M., Rinner A., Mair J., Alber H.F., Mittermayr M., Pachinger O. et al. Transient impairment of flowmediated vasodilation in patients with metabolic syndrome at moderate altitude (1700 m). International Journal Cardiology 2006;109: 82-87.

Mair J., Hammerer-Lercher A., Mittermayr M., Klingler A., Humpeler E. et al. 3-week hiking holidays at moderate altitude do not impair cardiac function in individuals with metabolic syndrome. International Journal Cardiology 2008;123:186-188.

Schobersberger W., Hoffmann G., Fries D., Gunga H.C., Greie S et al. AMAS (Austrian Moderate Altitude Study)-2000: Effects of hiking holidays at moderate altitude on immune system markers in persons with metabolic syndrome. Pteri-

dines 2004;15:149-154. Mueck-Weymann M., Leichtfried V., Schobersberger W., Hoffmann G., Greie S., Reicht I., Humpeler E. AMAS II (Austrian Moderate Altitude II): Auswirkungen eines einwöchigen Aktivurlaubs (1700 m) in mittleren Höhen auf bio-psychologische Parameter. In Schobersberger W. et al., Jahrbuch 2007 der Österreichischen Gesellschaft für Alpin und Höhenmedizin, Raggl digital graphic+print,

Innsbruck, 2007;209-226. Theiss H.D., Adam M., Greie S., Schobersberger W., Humpeler E., Franz W.M. Increased levels of circulating progenitor cells after 1-week sojourn at moderate altitude (Austrian Moderate Altitude Study II, AMAS II). Respiration Physiology

Neurobiology 2008;160:232-238. Burtscher M., Bachmann O., Hatzl T., Hotter B., Likar R., Philadelphy M., Nachbauer W. Cardiopulmonary and metabolic responses in healthy elderly humans during a 1-week hiking programme at high altitude. Eur J Appl Physiol 2001

May;84(5):379-86. Kacimi R., Richalet J.P., Corsin A., Abousahl I., Crozatier B. Hypoxia-induced downregulation of beta-adrenergic receptors in rat heart. J Appl Physiol 1992 Oct;73(4):1377-1382.

(13) (14) Haufe S., Wiesner S., Engeli S., Luft F.C. Jordan J. Influences of normobaric hypoxia training on metabolic risk markers in human subjects. Medicine & Sci-

ence in Sports & Exercise 2008; 40(11):1939-44. Borg G. Psychophysical bases of perceived exertion. Med Sci Sports Exerc 1982;14:377 – 381.