Biomedical subjects

Frank Ingjer

Publications and source records attributed to Frank Ingjer.

4 recordsLinked to original sources

PubMed2004

Factors affecting swimming economy in children and adults.

The aim of this study was to examine the influence of several explanatory factors: anthropometry, buoyancy, passive underwater torque, drag and swimming technique on the energy cost of swimming front crawl in children and adults. Submaximal V(.)O(2) was measured in ten children (age 12) and 13 adults (age 21), as well as body length (BL), body mass, arm length, propelling size, active drag, hydrostatic lift, passive torque, intracyclic velocity fluctuation, hand slip, stroke length and body angle. The results show that body length ( r=0.74), body mass ( r=0.86) propelling size ( r=0.61), arm length ( r=0.66), distance between the center of mass and the center of volume (Delta d, r=0.74) and body angle during swimming ( r=-0.56) all showed significant linear relationships with the cost of swimming at 1.0 m x s(-1) (CS(1.0)). When normalizing the cost of swimming to body size (CS(1.0) x BL(-1)) there were no differences between the two groups. The conclusions of this study are that the combination of BL, body mass, active drag factor, passive torque, drag efficiency and hydrostatic lift were able to explain 97% of the variation in the cost of swimming for the whole group of swimmers. The size-independent factors of torque and floating abilities (density and Delta d in % of BL), together with swimming technique and active drag were found to explain 75% of the variations in CS(1.0) x BL(-1). The identical values for CS(1.0) x BL(-1) for children and adults are explained through the opposing effects of a better swimming technique in the adults, and a better passive torque in the children.

Adolescent↗

PubMed2004

Hemodynamic changes during long meditation.

Changes in heart rate (HR) and blood pressure (BP) in advanced male meditators during 1 hr of meditation were compared with matched control participants resting for 1 hr. Also, changes in HR and BP during 3-hr meditation were analyzed. HR was recorded continuously during meditation (n = 38) and the control rest (n = 21). BP was measured before and after the meditation (n = 44) and the rest (n = 30). During the first hour, HR declined more in the meditators than the controls (p < .01). Within participant variability of HR was significantly lower during meditation than rest (p < .05). In the second hour of meditation, HR declined further (p = .01). BP was unaffected by either meditation or rest. In conclusion, meditation reduced the level of HR and within participant variability of HR more than rest. HR continued to decline during the second hour of meditation.

Adult↗

PubMed2003

Differences in the energy cost between children and adults during front crawl swimming.

There is little information available about the swimming economy of children. The aim of this study was to examine any possible differences in swimming economy in children and adults, swimming front crawl submaximally. Swimming economy was compared in adults [ n=13, aged 21.4 (3.7) years] and children [n=10, aged 11.8 (0.8) years] tested at four submaximal 6-min workloads. Oxygen consumption (VO2) was measured with Douglas bags in a 25-m pool and pacer lights were used to control the velocities. Swimming economy was scaled to body size using mass (BM), body surface area (BSA) and body length (BL). Children had lower VO2 (litres per minute) at a given velocity than the adults, with 1.86 (0.28) and 2.39 (0.20) l min(-1) respectively (at 1.00 m s(-1)). When scaling for size, children had higher VO2 measured in litres per square metre per minute and millilitres per kilogram per minute (divided by BSA and BM) than adults. The VO2 divided by BL was found not to differ between the two groups. The O2 cost of swimming 1 m at a velocity of 1.00 m s(-1) was lower in the children [31.0 (4.6) ml m(-1)] than in the adults [39.9 (3.3) ml m(-1) P<0.01], probably due to a lower total drag in the children. The results also showed that for children a relationship between swimming velocity cubed and VO2 exists as shown earlier for adults. It is concluded that, when scaling for BSA and BM, children are less economical than adults, when scaling for BL, children are equally economical, and when considering energy cost per metre and absolute VO2, children are more economical than the adults.

Adult↗

PubMed2003

High-intensity training with a bi-directional bicycle pedal improves performance in mechanically unstable ankles--a prospective randomized study of 19 subjects.

A bi-directional bicycle pedal that combines proprioceptive training and evertor strengthening has been developed for the treatment of residual instability after ankle sprains. A prospective randomized study was carried out on 19 subjects with recurrent ankle sprains and positive stress X-ray films. The subjects were randomized to use either a bi-directional test pedal or a traditional uni-directional bicycle pedal and then completed a 6-week high-intensity training program on a cycle ergometer. Assessment of training intensity level was based on maximum oxygen uptake values, heart rate and lactate concentration in blood at various submaximal workloads. After completion of the training program, the subjects who had used the test pedal increased peak eversion torque at 180 degrees degrees s-1 by 14.2% (P = 0.020), reduced figure-of-eight running time by 0.24 s (P = 0.003), improved single leg stance speed from 72.5% to the maximum speed of 80% (P = 0.005), and improved Karlsson functional score by 5.1 points (P = 0.005). In the control group, single leg stance improved from 56.1 to 67.8% (P = 0.018), but otherwise no significant effects were found. This study indicates that short-term high-intensity training with a bi-directional pedal improves ankle performance and may be an option in the treatment of recurrent ankle sprains.

Adult↗