Archive for May, 2007
Secular trends of physical fitness in Swedish adults
Secular trends of physical fitness in Swedish adults.
Ekblom B, Engström LM, Ekblom O
Scand J Med Sci Sports. 2007 Jun ; 17(3): 267-73
The aim of the present study was to study differences in fitness (maximal aerobic power (VO(2max)), balance control, abdominal strength and endurance) and anthropometric data in Swedish women and men (20-65 years of age) between two national cross-sectional samples, studied in 1990/1991 and 2000/2001, respectively. The absolute and relative VO(2max) (aerobic fitness), estimated from a submaximal test, declined with increasing age in both genders. The submaximal test was validated against running VO(2max). Furthermore, the relative aerobic fitness (mL/min/kg) was lower in the 2000/2001 sample in men but not in women.
Overall physical activity level was unchanged in both genders. An unexpected finding was that in both samples there were no major differences in relative VO(2max) between men and women of the same age. Combined overweight and obesity (body mass index>/=25) is becoming more prevalent in men, but not in women with prevalence in 2000/2001 of 61% and 38% for men and women, respectively. Balance control and abdominal strength and endurance decrease with increasing age with no differences between the two samples. Thus, the near future health situation for men may be worse, while for women it may be less or no differences compared with today.
Via HubMed Abstracts
Century boys track and field team tops Big Nine
Brian Wille took it for his Rochester Century team.
Then, he took it to the garbage can, where he hovered for about 20 minutes, waiting to throw up.
For Wille, it was all worth it. After all, he’d gone a long way toward bringing his Panthers the team title in Friday’s Big Nine Conference track and field meet. He’d done it by gutting it out in the two most grueling racers there are at the high school level, the 1,600 and the 3,200 meters.
Read the rest at Postbulletin.com
Exercise economy does not change after acclimatization to moderate to very high altitude
Exercise economy does not change after acclimatization to moderate to very high altitude.
Lundby C, Calbet JA, Sander M, van Hall G, Mazzeo RS, Stray-Gundersen J, Stager JM, Chapman RF, Saltin B, Levine BD
Scand J Med Sci Sports. 2007 Jun ; 17(3): 281-91
For more than 60 years, muscle mechanical efficiency has been thought to remain unchanged with acclimatization to high altitude. However, recent work has suggested that muscle mechanical efficiency may in fact be improved upon return from prolonged exposure to high altitude.
The purpose of the present work is to resolve this apparent conflict in the literature. In a collaboration between four research centers, we have included data from independent high-altitude studies performed at varying altitudes and including a total of 153 subjects ranging from sea-level (SL) residents to high-altitude natives, and from sedentary to world-class athletes.
In study A (n=109), living for 20-22 h/day at 2500 m combined with training between 1250 and 2800 m caused no differences in running economy at fixed speeds despite low typical error measurements. In study B, SL residents (n=8) sojourning for 8 weeks at 4100 m and residents native to this altitude (n=7) performed cycle ergometer exercise in ambient air and in acute normoxia.
Muscle oxygen uptake and mechanical efficiency were unchanged between SL and acclimatization and between the two groups. In study C (n=20), during 21 days of exposure to 4300 m altitude, no changes in systemic or leg VO(2) were found during cycle ergometer exercise. However, at the substantially higher altitude of 5260 m decreases in submaximal VO(2) were found in nine subjects with acute hypoxic exposure, as well as after 9 weeks of acclimatization.
As VO(2) was already reduced in acute hypoxia this suggests, at least in this condition, that the reduction is not related to anatomical or physiological adaptations to high altitude but to oxygen lack because of severe hypoxia altering substrate utilization. In conclusion, results from several, independent investigations indicate that exercise economy remains unchanged after acclimatization to high altitude.
Via HubMed Abstracts
