1.
Effects of Low Versus Moderate Glycemic Index Diets on Aerobic Capacity in Endurance Runners: Three-Week Randomized Controlled Crossover Trial.
Durkalec-Michalski, K, Zawieja, EE, Zawieja, BE, Jurkowska, D, Buchowski, MS, Jeszka, J
Nutrients. 2018;10(3)
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During athletic performance, adequate amounts of carbohydrates are required to prolong the onset of fatigue. Research on whether the glycaemic index (GI) of ingested carbohydrates effects performance has been explored but has produced equivocal results. The aim of this randomised crossover study was to assess the effect of low- and moderate- GI diets on the aerobic capacity and endurance performance in 21 runners. Participants consumed a low- and moderate- GI, high carbohydrate and nutrient balanced diets for three weeks each with a two-week washout period. Aerobic capacity and body composition were measured at the beginning and end of each diet period through various athletic performance tests. This study found that after a low-GI, high-carbohydrate diet, improvements were seen in time to exhaustion and running performance. Gas exchange was improved by both diets. The low-GI carbohydrate diet helped athletes to maintain a more stable blood glucose concentration during exertion tests. Based on these results the authors suggest considering GI when planning a diet for performance athletes, and also urge further research be completed to better understand the effects of long-term GI diets with regards to exercise performance.
Abstract
The glycemic index (GI) of ingested carbohydrates may influence substrate oxidation during exercise and athletic performance. Therefore, the aim of this study was to assess the effect of low- and moderate-GI three-week diets on aerobic capacity and endurance performance in runners. We conducted a randomized crossover feeding study of matched diets differing only in GI (low vs. moderate) in 21 endurance-trained runners. Each participant consumed both, low- (LGI) and moderate-GI (MGI) high-carbohydrate (~60%) and nutrient-balanced diets for three weeks each. At the beginning and end of each diet, participants had their aerobic capacity and body composition measured and performed a 12-min running test. After LGI, time to exhaustion during incremental cycling test (ICT) and distance covered in the 12-min run were significantly increased. The MGI diet led to an increase in maximal oxygen uptake ( V ˙ O₂max), but no performance benefits were found after the MGI diet. The LGI and MGI diets improved time and workload at gas exchange threshold (GET) during ICT. The results indicate that a three-week high-carbohydrate LGI diet resulted in a small but significant improvement in athletic performance in endurance runners. Observed increase in V ˙ O₂max on MGI diet did not affect performance.
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Does adapted physical activity‑based rehabilitation improve mental and physical functioning? A randomized trial.
Røe, C, Preede, L, Dalen, H, Bautz-Holter, E, Nyquist, A, Sandvik, L, Saebu, M
European journal of physical and rehabilitation medicine. 2018;54(3):419-427
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Physical and mental functioning is reduced in people with chronic disability. Adapted physical activity (APA) programmes have been developed to facilitate physical activity in this population, but the mental effects have not yet been addressed. The aim of this study was to determine both the physical and mental effects of an APA programme in 202 patients with chronic disability. Participants were randomised to either join an in-patient APA rehabilitation programme or a waitlist control group. Those in the APA programme received 2-5 hours of guided activity every day for 6 days a week, as well as 1-3 hours of a social or cultural activities. Various questionnaires were completed at baseline and at the end of the intervention. This study found participants receiving the APA rehabilitation programme showed improvements in physical functioning, motivation, self-efficacy (a feeling that 'I can do' an action), pain and fatigue compared with the waitlist group. Based on these results, the authors conclude physical activity should be considered during the development of rehabilitation strategies for people with chronic disabilities.
Abstract
BACKGROUND Persons with chronic disabilities face a wide variety of problems with functioning that affect their level of physical activity and participation. We have limited knowledge about the effect of adapted physical activity (APA)-based rehabilitation on perceived mental and physical functioning. AIM: The main aim of this study was to evaluate the effect of APA‑based rehabilitation compared to waiting‑list on perceived mental and physical functioning. Secondly, we wanted to assess whether improvement in self‑efficacy, motivation, pain and fatigue during rehabilitation was related to the effect of the intervention. DESIGN Randomized controlled trial. SETTING In‑patient rehabilitation Center. POPULATION All subjects above 17 years who were referred by their physician to BHC between July 1, 2010 and August 1, 2012 without major cognitive or language problems were eligible for the study (N.=321). METHODS Persons above 17 years (men and women) with chronic disabilities who applied for a rehabilitation stay, were randomized to an adapted physical activity‑based rehabilitation intervention (N.=304) or waiting‑list with delayed rehabilitation. A total of 246 consented and were allocated to four week intervention or a waiting‑list control group. The main outcome was physical and mental functioning evaluated four weeks after rehabilitation using the Medical Outcomes Study 12-Item Short‑Form Health Survey (SF-12). RESULTS Compared to waiting‑list the adapted physical activity‑based intervention improved physical and mental functioning. Improvement in physical functioning during rehabilitation was related to reduced pain, improved motivation and self‑efficacy. CONCLUSIONS The results indicate that an adapted physical activity‑based rehabilitation program improves functioning. Improved efficacy for managing disability may mediate the improvement in mental functioning. CLINICAL REHABILITATION IMPACT Adapted physical activity‑based rehabilitation should be considered during the development of rehabilitation strategies for people with chronic disabilities. Motivational and self‑efficacy aspects must be addressed when organizing and evaluating rehabilitation programs.