Physiological and psychological responses to 100 km cross-country skiing during 2 days.

AIM: Physical exercise can have beneficial as well as detrimental effects on body tissues. The purpose of this study was to examine how the body responds to a 2-day 100 km ski event. METHODS: Two-day follow-up, field trial to measure changes in body mass, postural response of heart rate, pain perception, range of joint movement, muscle circumferences, vertical jump, creatine kinase (CK) and profile of mood state to repeated long distance cross-country skiing during 2 days. SUBJECTS: 10 physically active men (34.8+/-9.7 y, 1.82+/-0.05 m, 76.1+/-6.6 kg, BMI: 23.0+/-1.5. kgxm-2) participating in the Finlandia Ski Race, covering a total distance of 100 km during 2 days. RESULTS: Cardiorespiratory loading was high (over 85% of the maximal heart rate). However, leg measurements showed no signs of edema or a decline in flexibility or functional strength. CONCLUSION: SUBJECTS with excellent aerobic fitness are able to ski at high intensity a total of 100 km over 2 successive days without any major adverse effects on the musculoskeletal system or mood state.

Hormonal responses to 100 km cross-country skiing during 2 days.

AIM: The purposes of this study were to investigate the resting levels and the acute hormonal responses of serum testosterone and cortisol, and with time-resolved immunofluorometric assay of luteinising hormone (LH) and follicle stimulating hormone (FSH), to daily repeated prolonged skiing. METHODS: Quasi-experimental design: short-term follow-up, (reversal) field trial to investigate the daily responses of blood hormones to repeated 50 km skiing during 2 days in men. PARTICIPANTS: 10 physically active men (34.8+/-9.7 y, 1.82+/-0.05 m, 76.1+/-6.6 kg, BMI: 23.0+/-1.5 kg.m(-2)) participating in the Finlandia Ski Race, covering a total distance of 100 km during 2 days. MEASURES: venous blood samples were obtained before and after skiing, and after 1 week's recovery, to determine the concentrations of testosterone, LH, FSH and cortisol in the blood. RESULTS: Testosterone was reduced by over 20% after both days (p=0.016 and 0.002, respectively). LH decreased after the 1( st) race by 37% and after the 2nd race by 44% (p=0.028, both). FSH secretion was stable and cortisol increased 2.2- and 2.6-fold after the races (p<0.001). CONCLUSIONS: The participants in the 2 days' prolonged skiing exercise went through a period of heavy physical stress. They showed changes in their serum testosterone, LH and cortisol concentrations, which, with the exception of the FSH secretion, alter the acute responses of both the adrenal cortex and the hypothalamus-pituitary-testicular axis. When training or competition programmes are planned it should taken into consideration that daily repeated high intensity prolonged skiing without a recovery day may cause hormonal overreaching.

The effects of a 4-day march on the lower extremities and hormonal balance.

The functional strength, flexibility, and ranges of motion of the lower extremities, as well as hormonal balance, estimated by urinary excretion of adrenaline and noradrenaline and serum determinations of testosterone and cortisol, were studied with six physically active army officers participating in a 4-day march totaling 185 km. Catecholamine excretion rates showed cumulatively increased sympathoadrenal stress, and the effects on serum testosterone and cortisol concentrations were minor. Also, leg measurements showed no signs of edema, decreases in flexibility, or decreases in functional strength. Most pain (75%) experienced by the subjects was located in the feet and caused by abrasions and blisters. Only a small portion of perceived pains (25%) was associated with muscle soreness. Serum creatine kinase activity was slightly (ca. 400-650%) increased during the marching days. Thus, soldiers who are in good physical condition and are accustomed to marching are able to walk four marathons on successive days, while carrying 10-kg backpacks, without any major adverse effects on the musculature of their lower extremities.

Children and core-periphery differences.

This study examines the differences between children's (0-15 yr of age) use of primary care services in core and peripheral municipalities in Uusimaa province in southern Finland following the implementation of the Primary Health Care Act (1972). In the ecological study (municipality-based), children's total use of primary health care services during 1973-1979 was continuously lower in peripheral municipalities than in core areas in spite of the Primary Health Care Act, the express purpose of which was to reduce regional differences. Some equalization of utilization of private practitioners occurred during this period. The individual-based study material collected in 1979 enabled us to control for the influences of (1) distance to the core of the municipality, (2) age of the child, (3) socio-economic status of the family, (4) type of visit and (5) diagnosis. These factors somewhat modified the influence of the core/periphery dichotomy, but the overall picture that children in the core use more primary health care services remained the same. This suggest that health care policy should be quite specific and based on detailed regional analysis, if equalization between core and peripheral municipalities is to be achieved.