Ambient conditions prior to Tokyo 2020 Olympic and Paralympic games: Considerations for acclimation or acclimatization strategies

The Tokyo Olympics and Paralympic games in 2020 will be held in hot and humid conditions. Heat acclimation (in a climatic chamber) or heat acclimatization (natural environment) is essential to prepare the (endurance) athletes and reduce the performance loss associated with work in the heat. Based on the 1990-2018 hourly meteorological data of...

Acetazolamide improves cerebral oxygenation during exercise at high altitude

Acute mountain sickness is thought to be triggered by cerebral hypoxemia and be prevented by acetazolamide (Actz). The effect of Actz on cerebral oxygenation at altitude remains unknown. In 16 members of the 2005 Dutch Cho Oyu (8201 m, Tibet) expedition, the influence of Actz and exercise (750 mg PO daily) on heart rate, peripheral and regional...

Resistance index of frostbite as a predictor of cold injury in arctic operations

Cold-induced vasodilation (CIVD) is mentioned as a mechanism that may prevent the occurrence of local cold injuries. The magnitude of the CIVD reaction differs considerably between subjects and there were some indications that those subjects with a fast CIVD reaction with high amplitude had a reduced risk for cold injuries. The purpose of this...

Randvoorwaarden aan een verblijf op grote hoogte bij bestaande gezondheidsproblemen [Preconditions for a stay in high altitude areas in the case of existing health problems]

Various symptoms can arise during a stay in high altitude areas (above 2500 m), such as tissue hypoxia and in particular pulmonary and brain oedema. Patients with existing health problems can expect to develop more complaints or more severe complaints at an earlier stage. For a number of these patients a stay in high altitude areas should be...

Aandachtspunten voor een optimale voorbereiding : Inspanning in de warmte (Exercise in a hot environment: Points of special interest for an optimal preparation)

An elevated core temperature is one of the underlying factors responsible for a decrease of performance during exercise in a hot environment. Therefore, strategies that minimise the rise in core temperature during exercise in the heat are likely to be effective in enhancing exercise performance. There are several strategies to minimise this...

Aandachtspunten voor een optimale voorbereiding: Inspanning in de warmte (Exercise in a hot environment: Strategies for an optimal preparation)

One of the underlying factors responsible for performance decrement during exercise in a hot environment appears to be an elevated core temperature. For this reason, strategies that minimise the rise in core temperature during exercise in the heat are likely to be effective in enhancing exercise performance. There are several strategies to...

Finger cold-induced vasodilation: A review

Cold-induced vasodilation (CIVD) in the finger tips generally occurs 5-10 min after the start of local cold exposure of the extremities. This phenomenon is believed to reduce the risk of local cold injuries. However, CIVD is almost absent during hypothermia, when survival of the organism takes precedence over the survival of peripheral tissue....

Temperature limit values for gripping cold surfaces

Objectives. At the request of the European Commission and in the framework of the European Machinery Directive, research was conducted jointly in five different laboratories to develop specifications for surface temperature limit values for the gripping and handling of cold items. Methods. Four hundred and fourteen experiments were run where...

Criteria for estimating acceptable exposure times in hot working environments: A review

Objectives: To revise the criteria used in the present 'Required Sweat Rate' standard ISO 7933 (1989) for the prediction of the maximum duration of work in hot environments. Methods: Review of the literature and in particular, of the bases for the present criteria. Results: A new method is proposed, to take into account the increase in core...

Cold induced peripheral vasodilation at high altitudes- a field study

A significant reduction in cold-induced vasodilation (CIVD) is observed at high altitudes. No agreement is found in the literature about acclimatization effects on CIVD. Two studies were performed to investigate the effect of altitude acclimatization on CIVD. In the first study 13 male subjects immersed the distal phalanx of the left middle...

The relative influence of physical fitness, acclimatization state, anthropometric measures and gender on the individual reaction to heat stress

An experiment was set up to quantify the relative influence of fitness, acclimatization, gender and anthropometric measures on physiological responses to heat stress. For this purpose, 12 male and 12 female subjects were exposed to a neutral [ambient temperature (T(a)) 21°C, relative humidity (r.h. 50%)], a warm, humid (T(a) 34°C, r.h. 80%) and...