Effects of a short-term aquatic exercise intervention on symptoms and exercise capacity in individuals with chronic fatigue syndrome/myalgic encephalomyelitis: a pilot study.

PURPOSE: This pilot pre-and post-intervention study investigated the effects of a short-term aquatic exercise programme on physiological outcomes, symptoms and exercise capacity in women with chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME). METHODS: Eleven women (54.8 ± 12.4 year) volunteered for the 5-week program; an initial 20-min aquatic exercise session then two self-paced 20-min sessions per week for 4 weeks. Pre- and post-intervention outcomes were physiological measures, 6 min Walk Test (6MWT), perceived exertion (RPE), hand grip strength, Sit-to-Stand, Sit-Reach test, Apley's shoulder test, FACIT questionnaire, and 24-h post-test tiredness and pain scores (0-10 visual analogue scale). Heart rates, RPE, 24- and 48-h post-session tiredness/pain scores were recorded each session. RESULTS: 6MWT distance increased by 60.8 m (p = 0.006), left hand grip strength by 6 kg (p = 0.038), Sit-Reach test by 4.0 cm (p = 0.017), right shoulder flexibility by 2.9 cm (p = 0.026), FACIT scores by 8.2 (p = 0.041); 24-h post-test tiredness and pain decreased by 1.5 and 1.6, respectively (p = 0.002). There were significant post-intervention increases in exercising heart rates (6MWT 4- and 6-min time points), oxygen saturation at 2-min, and reduced RPE at 4-min. Weekly resting and exercising heart rates increased significantly during the study but RPE decreased; immediately post- and 24-h post-session tiredness decreased significantly. There were no reports of symptom exacerbation. CONCLUSIONS: Five weeks of low-moderate intensity aquatic exercise significantly improved exercise capacity, RPE and fatigue. This exercise mode exercise may potentially be a manageable and safe physical activity for CFS/ME patients.

The acute effect of mouth only breathing on time to completion, heart rate, rate of perceived exertion, blood lactate, and ventilatory measures during a high-intensity shuttle run sequence.

This study investigated the effect of restricting nasal breathing during a series of 20-m shuttle runs. Ten male participants (mean age = 21.7 ± 2.4 years, height = 1.80 ± 0.62 m, mass = 79.2 ± 10.4 kg, sum of 4 skinfolds = 54.5 ± 7.8 mm) were required to either (a) dive on the ground and complete a rolling sequence (condition = GRD) or (b) complete the shuttles while staying on their feet and tagging the line with 1 foot, at the end of each 20-m segment (condition = STD). The shuttle runs were completed with and without a nose clip (no clip = nc; with a clip = clip) under 4 different trial conditions in a randomized order (GRDnc; GRDclip; STDnc; and STDclip), requiring the participants to return on 4 separate occasions separated by 5-7 days. Heart rate was recorded throughout each trial, and the rate of perceived exertion (RPE) was measured at the completion of each shuttle sequence. Pretrial and posttrial lactate and respiratory function measures were also recorded. The general linear model with repeated measures analysis indicated that there was a significant effect for Roll (GRD > STD) (p ≤ 0.05) but not for Clip (p > 0.05) on total time to completion in the trials. There was no significant interaction of the conditions (Roll × Clip) for RPE (p > 0.05). Similarly, there was no significant effect for blood lactate measured 3 minutes post the last shuttle for Roll (p > 0.05) and Clip (p > 0.05). There was a significant main effect on the HR across all 6 time points (i.e., pre, intervals 1-4 and 10 minutes post) (p ≤ 0.05) and for Roll (GRD > STD) (p ≤ 0.05), but not for Clip (p > 0.05). No significant effect of Roll or Clip was found for any of the recorded ventilation measures (p > 0.05). On the basis of these findings, the use of restricted nasal breathing, while performing a high-intensity shuttle sequence as a method of increasing the acute training effect on athletes, is questionable, so strength and conditioning coaches should carefully consider their rationale for using such a training strategy.

The Emerging Role of Hypoxic Training for the Equine Athlete.

This paper provides a comprehensive discussion on the physiological impacts of hypoxic training, its benefits to endurance performance, and a rationale for utilizing it to improve performance in the equine athlete. All exercise-induced training adaptations are governed by genetics. Exercise prescriptions can be tailored to elicit the desired physiological adaptations. Although the application of hypoxic stimuli on its own is not ideal to promote favorable molecular responses, exercise training under hypoxic conditions provides an optimal environment for maximizing physiological adaptations to enhance endurance performance. The combination of exercise training and hypoxia increases the activity of the hypoxia-inducible factor (HIF) pathway compared to training under normoxic conditions. Hypoxia-inducible factor-1 alpha (HIF-1α) is known as a master regulator of the expression of genes since over 100 genes are responsive to HIF-1α. For instance, HIF-1-inducible genes include those critical to erythropoiesis, angiogenesis, glucose metabolism, mitochondrial biogenesis, and glucose transport, all of which are intergral in physiological adaptations for endurance performance. Further, hypoxic training could conceivably have a role in equine rehabilitation when high-impact training is contraindicated but a quality training stimulus is desired. This is achievable through purpose-built equine motorized treadmills inside commercial hypoxic chambers.

The effects of moderate intensity training in a hypoxic environment on transcriptional responses in Thoroughbred horses.

This study investigated the effects of six weeks of normobaric hypoxic training on transcriptional expression of the genes associated with mitochondrial and glycolytic activities in Thoroughbred horses. Eight horses were divided into two groups of four. They completed an identical incremental, moderate intensity training program, except that one group trained in a hypoxic chamber with 15% oxygen for 30 min on alternate days except Sundays (HT), while the other group trained in normal air (NC). Prior to and post training, heart rate and blood lactate were measured during an incremental treadmill test. Muscle biopsy samples were taken prior to and 24 h post the training period for qPCR analysis of mRNA changes in VEGF, PPARγ, HIF-1α, PGC-1α, COX4, AK3, LDH, PFK, PKm and SOD-2. No significant differences between the HT and NC were detected by independent-samples t-test with Bonferroni correction for multiple comparisons (P>0.05) in relative changes of mRNA abundance. There were no significant differences between groups for heart rate and blood lactate during the treadmill test. The outcomes indicated that this hypoxia training program did not cause a significant variation in basal level expression of the selected mRNAs in Thoroughbreds as compared with normoxic training.