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- Sjöström, Rita, et al.
(author)
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Qualitative identification and characterisation of self-reported symptoms arising in humans during experimental exposure to cold air
- 2019
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In: International Journal of Circumpolar Health. - : Taylor & Francis. - 1239-9736 .- 2242-3982. ; 78:1
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Journal article (peer-reviewed)abstract
- Background: Exposure to cold air is associated with increased morbidity and mortality in the general population. It is difficult to study the effects of whole-body exposure to cold air under controlled conditions in real life. Objectives: The aim of this study was to (1) explore and describe the experience of symptoms in humans during experimental and controlled exposures to cold air, by using controlled environmental chamber exposures and qualitative methodology, and to (2) categorise the symptoms. Method: The study used a randomised, double blind design, in which 34 subjects undertook rest and moderate-intensity exercise in an environmental chamber set to two or three different temperatures (0, -10, and -17 degrees C) on separate occasions. During the chamber exposures, subjects were interviewed. Qualitative content analysis was selected as the method of analysis. Findings: Subjects reported 50 distinct symptoms during the exposures. The symptoms were grouped into ten sub-categories and two major categories; airway versus whole-body symptoms. Conclusion: We have identified a broad range of symptoms in humans undertaking rest and moderate-intensity exercise at sub-zero temperatures. The symptoms and their categories may well be used to more extensively and quantitatively map cold-induced morbidity.
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- Ahokas, Essi K., et al.
(author)
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A post-exercise infrared sauna session improves recovery of neuromuscular performance and muscle soreness after resistance exercise training
- 2023
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In: Biology of Sport. - : Termedia Sp. z.o.o.. - 0860-021X .- 2083-1862. ; 40:3, s. 681-689
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Journal article (peer-reviewed)abstract
- : The aim of this study was to investigate effects of a single infrared sauna (IRS) session on postexercise recovery of neuromuscular performance, autonomic nervous system function, subjective sleep quality, and muscle soreness. Male basketball players (n = 16) performed two trials consisting of a complex resistance exercise protocol (maximal strength with plyometrics), followed by either 20 min passive recovery (PAS) or IRS (temperature 43±5°C), in a randomized crossover design, with trials separated by one week. Recovery of neuromuscular performance was assessed using 20 m maximal sprint, maximal countermovement-jump (CMJ), and isometric leg press tests, performed 14 hours after exercise. Heart rate (HR), heart rate variability (HRV), sleep diary, muscle soreness, and indirect muscle damage markers were measured pre and post exercise. The decrease in CMJ performance from pre- to post-exercise was attenuated after IRS compared to PAS (p < 0.01). The IRS session resulted in higher HR and lower root mean square of successive differences between normal heartbeats (RMSSD), and high and low frequency power, compared to PAS (p < 0.002). Post-exercise night-time HR and HRV did not differ following IRS vs. PAS. Muscle soreness was less severe, and perceived recovery was higher after IRS compared to PAS (p < 0.01). Post-exercise IRS attenuated the drop in explosive performance and decreased subjective muscle soreness after resistance training, which may enhance mood, readiness, and physical performance of an athlete. A single IRS session had no detrimental effects on recovery of the autonomic nervous system.
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- Ahokas, E K, et al.
(author)
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Minimal effect of water immersion on markers of inflammation and muscle damage after intensive exercise
- 2019
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In: Proc Physiol Soc 44.
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Conference paper (peer-reviewed)abstract
- Water immersion methods, such as cold water immersion and contrast water therapy are popular recovery interventions after athletic training and competition. Nevertheless, post-exercise cold water immersion may actually inhibit hypertrophic signalling pathways and muscle adaptation to training (1). It is has been commonly assumed that the mechanism of impaired training adaptation is mediated by blunted inflammatory responses to muscle-damaging exercise, although this assumption has been questioned by recent data (2). A weakness of previous studies is omission of active recovery in water immersion interventions, which would arguably be utilised in addition to water immersion by athletic populations. The aim of this study was to compare the influence of three water immersion methods, performed after active recovery, on inflammatory responses to muscle-damaging exercise. Nine male participants (age 20-35 y) performed an intensive exercise protocol, consisting of maximal jumps and sprinting, on four occasions. After each trial, participants completed one of four recovery protocols in a randomised, crossover design (ACT, active recovery only, 10 min cycling; heart rate 120-140 b/min; CWI, active recovery followed by 10 min cold water immersion, 10°C; TWI, active recovery followed by 10 min temperate water immersion, 24°C and CWT, active recovery followed by contrast water therapy, 10 min alternating 10°C and 38°C in 1 min cycles). The study was conducted in accordance with the Declaration of Helsinki and approved by the local ethical review board. Venous blood samples were collected pre-exercise and 5 min, 60 min, 24 h, 48 h and 96 h post-exercise, then analysed for myocyte chemoattractant protein 1 (MCP-1) and creatine kinase (CK) using ELISA and high-sensitivity C-reactive protein (hs-CRP) using a chemiluminescence assay. Two-way repeated measures ANOVA was used to compare biomarker concentrations between groups over time. There were no differences in biomarker concentrations during exercise and recovery between groups across the six time points, however main effects of time were present for all three markers (MCP-1: F(2.32, 18.56) = 23.1, p < 0.0001; CK: F(2.059, 16.47) = 8.74, p = 0.002; hs-CRP: F(1.07, 8.57 = 13.8, p = 0.005). Tukey’s post-hoc analysis of simple time effects revealed increases in MCP-1 at post-5 min versus pre in all groups except CWT. In TWI and CWI, MCP-1 was still elevated above pre at 60 min post-exercise. hs-CRP peaked at 24 h post-exercise in all groups. CK was elevated at post-60 versus pre in all groups and at post-24 except in CWT. Our findings suggest that use of cold or thermoneutral water immersion in combination with active recovery may slightly prolong the immediate post-exercise elevation in MCP-1 but have minimal overall effect on markers of inflammation and muscle damage.
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- Ahokas, Essi K., et al.
(author)
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Nocturnal Heart Rate Variability in Women Discordant for Hormonal Contraceptive Use
- 2023
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In: Medicine & Science in Sports & Exercise. - : Ovid Technologies (Wolters Kluwer Health). - 0195-9131 .- 1530-0315. ; 55:7, s. 1342-1349
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Journal article (peer-reviewed)abstract
- Purpose The aim of this study was to investigate within-cycle differences in nocturnal heart rate (HR) and heart rate variability (HRV) in naturally menstruating women (NM) and women using combined hormonal contraceptives (CU) or progestin-only hormonal contraceptives (PU).Methods Physically active participants were recruited into three groups: NM (n = 19), CU (n = 11), and PU (n = 12). Participants’ HR and HRV (with Bodyguard 2 HRV monitor), and blood hormones were monitored during one menstrual cycle (MC) (NM-group) or for 4 weeks (CU and PU-groups). Estradiol, progesterone, and luteinizing hormone were analyzed from fasting blood samples collected four times in the NM (M1 = bleeding, M2 = follicular phase, M3 = ovulation, and M4 = luteal phase) and PU groups (M1 = lowest E2; M2 = M1 + 7 days; M3 = M1 + 14 days; M4 = M1 + 21 days) and twice in the CU group (active and inactive pill phases). After every blood sample, nightly HR and HRV were recorded and examined as an average from two nights.Results Hormonal concentrations differed (p < 0.05) between MC phases in the NM- and PU-groups, but not (p ≥ 0.116) between the active and inactive phases in the CU-group. In the NM- and PU-groups, some of the HRV values were higher, while in the NM-group, HR was lower during M2 compared to M3 (p < 0.049) and M4 (p < 0.035). In the CU-group, HRV values (p = 0.014-0.038) were higher, and HR was lower (p = 0.038) in the inactive phase compared to the first week of the active phase.Conclusions The MC and hormonal cycle phases influence autonomic nervous system balance, which is reflected in measurements of nocturnal HR and HRV. This should be considered when monitoring recovery in physically active individuals.
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- Ahokas, E. K., et al.
(author)
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Water immersion methods do not alter muscle damage and inflammation biomarkers after high-intensity sprinting and jumping exercise
- 2020
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In: European Journal of Applied Physiology. - : Springer Science and Business Media LLC. - 1439-6319 .- 1439-6327. ; 120, s. 2625-2634
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Journal article (peer-reviewed)abstract
- Purpose: The aim of this study was to compare the efficacy of three water immersion interventions performed after active recovery compared to active recovery only on the resolution of inflammation and markers of muscle damage post-exercise. Methods: Nine physically active men (n = 9; age 20‒35 years) performed an intensive loading protocol, including maximal jumps and sprinting on four occasions. After each trial, one of three recovery interventions (10 min duration) was used in a random order: cold-water immersion (CWI, 10 °C), thermoneutral water immersion (TWI, 24 °C), contrast water therapy (CWT, alternately 10 °C and 38 °C). All of these methods were performed after an active recovery (10 min bicycle ergometer), and were compared to active recovery only (ACT). 5 min, 1, 24, 48, and 96 h after exercise bouts, immune response and recovery were assessed through leukocyte subsets, monocyte chemoattractant protein-1, myoglobin and high-sensitivity C-reactive protein concentrations. Results: Significant changes in all blood markers occurred at post-loading (p < 0.05), but there were no significant differences observed in the recovery between methods. However, retrospective analysis revealed significant trial-order effects for myoglobin and neutrophils (p < 0.01). Only lymphocytes displayed satisfactory reliability in the exercise response, with intraclass correlation coefficient > 0.5. Conclusions: The recovery methods did not affect the resolution of inflammatory and immune responses after high-intensity sprinting and jumping exercise. It is notable that the biomarker responses were variable within individuals. Thus, the lack of differences between recovery methods may have been influenced by the reliability of exercise-induced biomarker responses.
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| 8. |
- Ahokas, Essi, et al.
(author)
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Menstruation has no effect on heart rate variability and subjective sleep quality of physically active women
- 2021
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Conference paper (other academic/artistic)abstract
- INTRODUCTION:Subjective sleep quality may decrease during menstruation, although the duration and composition of sleep remains relatively stable across the menstrual cycle (MC) (1). Recording heart rate variability (HRV) is a tool to monitor the autonomic nervous system and recovery of the body. Meta-analytical data has not revealed significant changes in HRV from the early follicular phase (menses) to the mid-follicular phase (2). However, reduced HRV-values were observed during menses compared to follicular phase in women with pain during menses (dysmenorrhea) (3). Only a few studies have examined effects of the MC on nocturnal HRV. The aim of this study was to investigate how menses and associated pain affects nocturnal HRV and subjective sleep quality.METHODS:Participants included 14 healthy, physically active women, who did not use hormonal contraception. During one MC, participants completed a diary of sleep, MC and related symptoms. HRV was registered every night (Bodyguard 2, Firstbeat Technologies Ltd., Finland). HRV-data (RMSSD and LF/HF-ratio) were analyzed for two nights after a blood sample and over a four-hour period beginning 30 min after bedtime. Only the menses (M) and mid-follicular phases (FP) are used in this study. Blood samples (estradiol, E2, and progesterone, P4) were collected during M (day 2-3 of the MC) and FP (day 7-10) to ensure normal hormonal function associated with the MC (4).RESULTS:E2 was higher (p=0.012) during FP (267±150 pmol/L) compared to M (143±88 pmol/L), but P4 remained stable (p=0.103). Mean heart rate (HRmean) was higher during M (54±8 beats/min) compared to FP (52±7 beats/min, p=0.022). However, HRV-variables did not differ between M and FP (RMSSD: 76.7±34.5 to 77.3±27.0 ms, p=0.872; LF/HF: 1.416±1.380 to 1.273±0.769, p=0.826). Subjectively-assessed sleep quality remained unchanged between M and FP (p=0.349). The change in RMSSD and HRmean between M and FP did not differ (RMSSD: p=0.728; HRmean: p=0.149) between participants with and without menstrual pains.CONCLUSION:Menses has no effect on nocturnal HRV and subjective sleep quality of physically active women, though the higher nocturnal HRmean during M may indicate decreased recovery during menses.REFERENCES:1. Driver, H.S., Werth, E., et al. The Menstrual Cycle Effects on Sleep. Sleep Med Clin 2008, 3:1–11.2. Schmalenberger, K.M., Eisenlohr-Moul, T.M., et al. A Systematic Review and Meta-Analysis of Within-Person Changes in Cardiac Vagal Activity across the Menstrual Cycle: Implications for Female Health and Future Studies. J Clin Med 2019, 8:1946.3. Jayamala, A.K., Preethi, B.L., et al. Comparative Analysis of Heart Rate Variability During Different Phases of Menstrual Cycle in Eumenorrhea & Dysmenorrhea Subjects. Exp Clin Physiol Biochem 2017, 1.4. Elliot-Sale, K.J., Minahan, C.L., et al. Methodological Considerations for Studies in Sport and Exercise Science with Women as Participants: A Working Guide for Standards of Practice for Research on Women. Sports Med 2021, 51:843–861.
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- Ainegren, Mats, 1963-, et al.
(author)
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Breathing resistance in heat and moisture exchanging devices
- 2022
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In: Proceedings of the Institution of Mechanical Engineers, Part P. - : Sage Publications. - 1754-3371. ; 236:2, s. 97-105
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Journal article (peer-reviewed)abstract
- The purpose of this study was to investigate the resistance to breathing (RES) in heat and moisture exchanging devices (HME) intended for use during physical activity in the cold. RES was investigated for seventeen HMEs, including different types of filters. In addition, the influence of headwind on RES was tested using four representative HMEs. HMEs were mounted to the face of an artificial head manufactured from ABS plastic. The HMEs were connected to a mechanical lung simulator, which delivered standardised inspiratory and expiratory air flow rates (V⋅, L/s). The delta pressure (Δp, Pa) between ambient air and the air inside the HME was measured, whereupon RES was calculated. The results showed significant (p < 0.05) differences in RES between HMEs from different manufacturers, while the difference was smaller, and in some cases not significant (p > 0.05), between different models/filters within the same brand. The results also showed that RES was highly influenced by different ventilations and headwind conditions. RES increased with increased V⋅ and, when a headwind was introduced, RES decreased during inspiration and increased during expiration. Calculations showed that the oxygen and energy cost for breathing through an HME was very small for most of the tested models. The effect of HME dead space on pulmonary gas fractions depends on the tidal volume. At large tidal volumes and ventilations, the effect of HMEs on pulmonary gas fractions becomes relatively small.
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- Blakeson, Magdalene C., et al.
(author)
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Illness Incidence, Psychological Characteristics, and Sleep in Dogsled Drivers During the Iditarod Trail Sled Dog Race
- 2022
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In: Wilderness & environmental medicine (Print). - : Elsevier BV. - 1080-6032 .- 1545-1534. ; 33:1, s. 92-96
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Journal article (peer-reviewed)abstract
- Introduction: Every March, dogsled drivers (mushers) compete in a 1569-km race across Alaska, involving physical exertion, mental exertion, and sleep deprivation for up to 2 wk. These factors may increase mushers’ vulnerability to illness, making them a relevant study population for acute infection risk factors. Specifically, the influence of psychological factors on illness risk during prolonged physical exertion has rarely been investigated. The aim of this study was to examine the relationship between psychological characteristics, sleep deprivation, and illness incidence in Iditarod mushers. Methods: Fourteen mushers completed 4 psychological instruments to assess state and trait anxiety, resilience and perceived stress, and self-reported upper respiratory symptoms (URS) in the month before the race. Mushers self-reported sleep duration and URS during the race. Results: State and trait anxiety, resilience, and perceived stress did not differ between mushers with and without pre- and in-race URS (P>0.05). However, all mushers who reported in-race URS had reported URS ≤9 d before the race, and the onset of symptoms during the race typically occurred shortly after a rest period. Sleep duration was higher in mushers who reported in-race URS, both before (4.9±0.3 h, P=0.016) and during illness (5.9±1.3 h, P=0.006), vs mushers without in-race URS (3.4±0.8 h). Conclusions: This study highlights recent illness, rest periods, and greater sleep requirements as potential risk factors for URS onset during a multiday endurance challenge, whereas psychological factors were not associated with URS.
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