( Hulston et al., 2010 ; Yeo et al., 2008 ). In some instances, both exercise capacity ( Hansen et al., 2005 ) and exercise performance ( Cochran et al., 2015 ; Marquet et al., 2016a , 2016b ) have also been augmented with short-term (i.e., 3–10 weeks) train-low approaches, though it is acknowledged that
Sally P. Waterworth, Connor C. Spencer, Aaron L. Porter and James P. Morton
Kenneth Coutts, Donald McKenzie, Christine Loock, Richard Beauchamp and Robert Armstrong
The purpose of this study was to describe the upper body exercise capabilities of youth with spina bifida, which would permit comparison of their abilities to norms. Forty-two children with spina bifida age 7 to 18 years were tested for maximal handgrip strength, anaerobic arm-crank power output, and peak arm-crank oxygen uptake. Analysis of variance was used to compare age, gender, and level of disability differences within the total sample. This analysis indicated no significant effect of level of disability on any of the upper body exercise capacity measures. Significant gender and age effects were noted for grip strength and anaerobic and aerobic capabilities. The sample exhibited handgrip strength comparable to that of nondisabled youth but low anaerobic power and peak oxygen uptake values. Some individual subjects, however, had “normal” values for all tests suggesting that a lower level of participation in regular physical activity rather than spina bifida per se may be responsible for the generally lower physical capacity found in the total sample.
Stuart D.R. Galloway, Matthew J.E. Lott and Lindsay C. Toulouse
The present study aimed to investigate the influence of timing of preexercise carbohydrate feeding (Part A) and carbohydrate concentration (Part B) on short-duration high-intensity exercise capacity. In Part A, 17 males, and in Part B 10 males, performed a peak power output (PPO) test, two familiarization trials at 90% of PPO, and 4 (for Part A) or 3 (for Part B) experimental trials involving exercise capacity tests at 90% PPO. In Part A, the 4 trials were conducted following ingestion of a 6.4% carbohydrate/electrolyte sports drink ingested 30 (C30) or 120 (C120) minutes before exercise, or a flavor-matched placebo administered either 30 (P30) or 120 (P120) minutes before exercise. In Part B, the 3 trials were performed 30 min after ingestion of 0%, 2% or 12% carbohydrate solutions. All trials were performed in a double-blind cross-over design following and overnight fast. Dietary intake and activity in the 2 days before trials was recorded and replicated on each visit. Glucose, lactate, heart rate, and mood/arousal were recorded at intervals during the trials. In Part A, C30 produced the greatest exercise capacity (mean ± SD; 9.0 ± 1.9 min, p < .01) compared with all other trials (7.7 ± 1.5 min P30, 8.0 ± 1.7 min P120, 7.9 ± 1.9 min C120). In Part B, exercise capacity (min) following ingestion of the 2% solution (9.2 ± 2.1) compared with 0% (8.2 ± 0.7) and 12% (8.0 ± 1.3) solutions approached significance (p = .09). This study provides new evidence to suggest that timing of carbohydrate intake is important in short duration high-intensity exercise tasks, but a concentration effect requires further exploration.
Martin J. Barwood, Joe Kupusarevic and Stuart Goodall
Purpose: Exercise performance is impaired in the heat, and a contributing factor to this decrement is thermal discomfort. Menthol spraying of skin is one means of alleviating thermal discomfort but has yet to be shown to be ergogenic using single-spray applications. The authors examined whether repeated menthol spraying could relieve thermal discomfort, reduce perception of exertion, and improve exercise performance in hot (35°C), dry (22% relative humidity) conditions, hypothesizing that it would. Methods: A total of 8 trained cyclists completed 2 separate conditions of fixed-intensity cycling (50% maximal power output) for 45 min before a test to exhaustion (TTE; 70% maximal power output) with 100 mL of menthol spray (0.20% menthol) or control spray applied to the torso after 20 and 40 min. Perceptual (thermal sensation, thermal comfort, and rating of perceived exertion) performance (TTE duration), thermal variables (skin temperature, rectal temperature, and cardiac frequency), and sweating were measured. Data were compared using analysis of variance to .05 alpha level. Results: Menthol spray improved thermal sensation (cold sensation cf warm/hot after first spraying; P = .008) but only descriptively altered thermal comfort (comfortable cf uncomfortable; P = .173). Sweat production (994  mL cf 1180  mL; P = .020) and sweat rate (827  mL·h−1 cf 941  mL·h−1; P = .048) lowered. TTE performance improved (4.6 [1.74] cf 2.4 [1.55] min; P = .004). Menthol-spray effects diminished despite repeated applications, indicating increased contribution of visceral thermoreceptors to thermal perception. Conclusion: Repeated menthol spraying improves exercise capacity but alters thermoregulation, potentially conflicting behavioral and thermoregulatory drivers; care should be taken with its use. Carrying and deploying menthol spray would impose a logistical burden that needs consideration against performance benefit.
Aleksandar Sovtic, Predrag Minic, Jovan Kosutic, Gordana Markovic-Sovtic and Milan Gajic
The modified Chrispin-Norman radiography score (CNS) is used in evaluation of radiographic changes in children with cystic fibrosis (CF). We evaluated the correlation of modified CNS with peak exercise capacity (Wpeak) and ventilatory efficiency (reflected by breathing reserve index—BRI) during progressive cardiopulmonary exercise testing (CPET). Thirty-six children aged 8–17 years were stratified according to their CNS into 3 groups: mild (<10), moderate (10–15), and severe (>15). CPET was performed on a cycle ergometer. Lung function tests included spirometry and whole-body plethysmography. Patients with higher CNS had lower FEV1 (p < .001), Wpeak predicted (%; p = .01) and lower mean peak oxygen consumption (VO2peak/kg; p = .014). The BRI at the anaerobic threshold and at Wpeak was elevated in patients with the highest CNS values (p < .001). The modified CNS correlates moderately with Wpeak (R = −0.443; p = .007) and BRI (R = −0.419; p = .011). Stepwise multiple linear regression showed that RV/TLC was the best predictor of Wpeak/pred (%; B = −0.165; b = −0.494; R2 = .244; p = .002). Children with CF who have high modified CNS exhibit decreased exercise tolerance and ventilatory inefficacy during progressive effort.
Conor Taylor, Daniel Higham, Graeme L. Close and James P. Morton
The aim of this study was to test the hypothesis that adding caffeine to postexercise carbohydrate (CHO) feedings improves subsequent high-intensity interval-running capacity compared with CHO alone. In a repeated-measures design, 6 men performed a glycogen-depleting exercise protocol until volitional exhaustion in the morning. Immediately after and at 1, 2, and 3 hr postexercise, participants consumed 1.2 g/kg body mass CHO of a 15% CHO solution, a similar CHO solution but with addition of 8 mg/kg body mass of caffeine (CHO+CAFF), or an equivalent volume of flavored water only (WAT). After the 4-hr recovery period, participants performed the Loughborough Intermittent Shuttle Test (LIST) to volitional exhaustion as a measure of high-intensity interval-running capacity. Average blood glucose values during the 4-hr recovery period were higher in the CHO conditions (p < .005) than in the WAT trial (4.6 ± 0.3 mmol/L), although there was no difference (p = .46) between CHO (6.2 ± 0.8 mmol/L) and CHO+CAFF (6.7 ± 1.0 mmol/L). Exercise capacity during the LIST was significantly longer in the CHO+CAFF trial (48 ± 15 min) than in the CHO (32 ± 15 min, p = .04) and WAT conditions (19 ± 6 min, p = .001). All 6 participants improved performance in CHO+CAFF compared with CHO (95% CI for mean difference = 1–32 min). The study provides novel data by demonstrating that adding caffeine to postexercise CHO feeding improves subsequent high-intensity interval-running capacity, a finding that may be related to higher rates of postexercise muscle glycogen resynthesis previously observed under similar feeding conditions.
Kym Joanne Price, Brett Ashley Gordon, Kim Gray, Kerri Gergely, Stephen Richard Bird and Amanda Clare Benson
during recovery ( Ades et al., 2006 ; Oldridge & Stump, 2004 ). Therefore, patients entering cardiac rehabilitation have a considerably lower (by approximately 60% in males) exercise capacity than age-matched individuals free of coronary heart disease ( Ades et al., 2006 ). This concurs with self
Ítalo Ribeiro Lemes, Xuemei Sui, Stacy L. Fritz, Paul F. Beattie, Carl J. Lavie, Bruna Camilo Turi-Lynch and Steven N. Blair
capacity less than 9.0 METs. These results suggest that an exercise capacity of at least 9.0 METs is needed to provide protective benefits. Chronic musculoskeletal conditions are recognized health issues that affect people across the world. In Thailand, a chronic condition, such as low back pain, is a
Michael Barker, Ulrich Merz, Minou S. Hertl and Gerhard Heimann
Pulmonary function and exercise performance were evaluated in a cohort of 26 children born prematurely at very low birth weight (VLBW) and compared to healthy term controls (age 8-14 years). Children with a history of bronchopulmonary dysplasia (BPD) had slightly lower lung resting function than those without BPD or controls. Oxygen uptake kinetics in the aerobic range were similar in all three groups. With incremental exercise, however, preterm children with and without BPD demonstrated ventilatory limitation with significantly lower peak work rates. A closer pulmonary follow-up including an exercise test may thus appear warranted after preterm delivery at VLBW.
Amanda Claassen, Estelle V. Lambert, Andrew N. Bosch, Ian M. Rodger, Alan St. Clair Gibson and Timothy D. Noakes
The impact of altered blood glucose concentrations on exercise metabolism and performance after a low carbohydrate (CHO) diet was investigated. In random order, 1 wk apart, 9 trained men underwent euglycemic (CI) or placebo (PI) clamps, while performing up to 150 min of cycling at 70% VO2max, after 48 h on a low CHO diet. The range in improvement in endurance capacity with glucose infusion was large (28 ± 26%, P < 0.05). Fifty-six percent of subjects in CI failed to complete 150 min of exercise despite maintenance of euglycemia, while only 2 subjects in PI completed 150 min of exercise, despite being hypoglycemic. Total CHO oxidation remained similar between trials. Despite longer exercise times in CI, similar amounts of muscle glycogen were used to PI. Maintenance of euglycemia in the CHO-depleted state might have an ergogenic effect, however, the effect is highly variable between individuals and independent of changes in CHO oxidation.