Cost of locomotion during loaded marching in the heat
Notice bibliographique
Résumé
Although exercise in the heat and its effect on thermoregulatory responses has been well studied, limited information is available concerning the effect of high environmental temperatures on thermoregulatory responses, cardiovascular strain and cost of locomotion during loaded marching in the heat. Members of the armed forces are wearing protective equipment like bulletproof vests, helmets and tactical vests while performing a loaded march, often in high environmental temperatures, which could potential expose the individual uncompensable heat stress. Therefore, the purpose of this study was to investigate the effect of elevated environmental temperature on core and body temperature, heart rate and cost of locomotion in military service members during a 5 km loaded march. Participants were seven service members of the Canadian Armed Forces Light Infantry (age 24±6 years, height 178±5 cm, weight 78.8±14.7 kg, VO2max 49.2±5.6 ml·min −1 ·kg −1 , lean body mass 66.3±8.3 kg, body fat % 14.9±6.5), who performed a loaded march carrying 35 kg of equipment, under two environmental conditions ( NORMAL 21°C and 50 relative humidity (RH), and HOT 30°C and 50% RH). Treadmill speed was set to 5.17km/h and the incline was set to 1% to simulate level ground walking. The 35 kg external load consisted of military boots, uniform, helmet, fragmentation vest, tactical vest, a Colt 7 replica rubber rifle and a loaded day pack. Participants walked on the treadmill for 60 min, or until voluntary termination. Heart rate was measured using a Garmin 310xt heart rate monitor, while energy expenditure was calculated from O2 consumption and CO2 production, using an open circuit flow through metabolic system. Cost of locomotion was calculated as energy expended per kg weight (body weight and external load) per kilometer walked (J·kg −1 ·km −1 ). Core temperature was measured using a telemetric pill (Jonah Temperature Capsule). All participants completed the loaded march in the normal condition, however one participant was unable to complete the full hour in the HOT condition due to gastric distress. Heart rate was significantly higher from 25 min until the end of the loaded march when participants performed the loaded march in the HOT condition compared to NORMAL . Heart rate during the last 5 min in the HOT condition was 152±11 bpm, compared to 136.9±13.2 bpm in the NORMAL condition. Core temperature was significantly higher in the HOT condition compared to NORMAL , and was 38.2±0.5°C in the HOT condition compared to 37.7±0.3°C in the NORMAL condition after 60 min of loaded march. Cost of locomotion (J·kg −1 ·km −1 ) was also affected by environmental temperature, and was significantly higher in the HOT condition compared to NORMAL (AUC hot 165.5±10.4 vs normal 152. ±8.9). The results from this study shows that performing a loaded march at 30°C and 50% RH wearing military protective equipment lead to uncompensable heat stress, causing an increase in core temperature and heart rate (cardiovascular strain). We also observed that the uncompensable heat stress caused an increase in the cost of locomotion without changing any factors other than environmental temperature.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,002 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».