Are athletes able to self-select their optimal warm up?

This study aimed to examine whether athletes are able to self-select their optimal warm up and to propose a methodological approach in investigating the effects of warm up on performance. Nine male subjects underwent a free field warm up (FWU) at a self-selected intensity and duration during which heart rate (HR) and rectal temperature (Tre) were monitored. The intensity of this warm up was subsequently estimated from the HR obtained during an incremental test to determine maximal power (Pmax). Performance (cycle time to exhaustion at Pmax), HR and Tre, were then examined following either: NWU (no warm up); RWU (reference warm up based on FWU); RWU-10 (warm up intensity diminished by 10% compared to RWU); and RWU+10 (warm up intensity increased by 10% compared to RWU). Results showed no significant difference in HR (P = 0.37) and Tre increase (P= 0.77) between FWU and RWU. Performance improvement after warm up conditions gave RWU (56%; ie, 5/9 subjects) >RWU-10 (33%; ie, 3/9) >RWU+10 (11%; ie, 1/9) >NWU with significant differences between RWU and NWU (P < 0.01); RWU and RWU+10 (P < 0.01); RWU-10 and NWU (P < 0.01). A warm up intensity ranging from 54-72% Pmax, and inducing an increase in heart rate to 80 +/- 6% HRmax, was found to be optimal. While most athletes were able to self-determine the intensity of their optimal warm up, for others there is still a need for control.

[Effects of preliminary muscular exercise on body temperature, water loss and physical performance]. / Effets d'un exercice musculaire préliminaire sur la température centrale, les pertes hydriques et la performance physique.

We investigated the effects of preliminary exercise (muscular warm-up) on body temperature, water loss and physical performance during consecutive sustained exercise. Thirty-one untrained men aged 21 to 30 years old (mean 25.12 +/- 2.92) were subjected to two physical trial tests at 75% Pma. One trial. (T - PE) was performed without preliminary exercise (PE) and the other (T + PE) was preceded by 15 minutes of preliminary exercise performed at 50% Pma. The trials involved pedaling an ergocycle until exhaustion, followed by a 30 minutes period of inactive recovery. The rate of increase of body temperature during the work consecutive to preliminary exercise (T + PE) was lower than that of the work without preliminary exercise (T - PE). The energy output and water loss during T + PE were significantly (P < 0.01) greater than during T - PE. However, the body temperatures at the end of the two tests were identical. The rate of decrease of body temperature, measured after 30 minutes of recovery, was higher for T + PE than T - PE. The duration of work was increased by PE for 25 (80.65%) subjects and decreased for 6 (19.35%). We conclude that preliminary exercise allows better adjustment of thermohydric regulation by moderating the rise in body temperature and increasing water loss during physical work. For most subjects, these adjustments allow improved endurance.

[Functional and immunologic involvement in human African trypanosomiasis caused by Trypanosoma gambiense]. / Atteintes fonctionnelles et immunologiques au cours de la trypanosomiase humaine africaine à Trypanosoma gambiense.

In the first phase of our study, a group of 58 patients were investigated: electromyographic abnormalities were recorded in 52%, electrocardiographic abnormalities in 48%, electroencephalographic abnormalities in 47%, spirographic abnormalities in 31%. Impairments of central nervous system occur classically in Trypanosoma gambiense infection, while cardiac damage is more frequent in T. rhodesiense infection. Noted lesions are due to an immunological mechanism. In the second phase, 25 patients and controls from the same area were investigated. We tried to confirm existence and pathogeny of cardiac impairments in T. gambiense infection: incidence, symptoms, clinical and electrocardiographic signs, disturbances of cardiac rythm. There were ST segment, T wave and PR interval changes. Chest X ray showed cardiomegaly. Echocardiography revealed right ventricular dilatation. There were pericardial effusion and thickening. The immunological tests showed significantly higher IgM and immunoconglutinin levels in the patient group together with the presence of anti-heart antibodies of the IgM and IgG class. Our results suggest that cardiac impairments may be due to immune complexes.