Effects of training and competition on the sleep of elite athletes: a systematic review and meta-analysis.

OBJECTIVES: To characterise the sleep of elite athletes and to identify factors associated with training and competition that negatively affect sleep. DESIGN: Prognosis systematic review. DATA SOURCES: Three databases (PubMed, SCOPUS and SPORTDiscus) were searched from inception to 26 February 2018. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Included studies objectively reported total sleep time (TST) and/or sleep efficiency (SE) in elite athletes. Studies were required to be observational or to include an observational trial. RESULTS: Fifty-four studies were included. During training, many studies reported athletes were unable to achieve TST (n=23/41) and/or SE (n=16/37) recommendations. On the night of competition, most studies reported athletes were unable to achieve TST (n=14/18) and/or SE (n=10/16) recommendations. TST was shorter (60 min) the night of competition compared with previous nights. SE was lower (1%) the night of competition compared with the previous night. TST was shorter the night of night competition (start ≥18:00; 80 min) and day competition (20 min) compared with the previous night. SE was lower (3%-4%) the night of night competition but unchanged the night of day competition compared with previous nights. Early morning training (start <07:00), increases in training load (>25%), late night/early morning travel departure times, eastward air travel and altitude ascent impaired sleep. CONCLUSION: Athletes were often unable to achieve sleep recommendations during training or competition periods. Sleep was impaired the night of competition compared with previous nights. Early morning training, increases in training load, travel departure times, jet lag and altitude can impair athletes' sleep. PROSPERO REGISTRATION NUMBER: CRD42017074367.

Blood flow restriction walking and physical function in older adults: A randomized control trial.

OBJECTIVES: The progressive age-related declines in muscle health and physical function in older adults are related to muscle size and strength. Walking with an applied blood flow restriction is an alternative to maintain muscle volume in older adults to increase the value for time spent walking. Therefore, the aim of this study was to examine the effect of adding blood flow restriction to low-intensity walking on clinical measures of physical function. DESIGN/METHODS: Sedentary older men and women were randomised to either a low-intensity blood flow restriction walking group (BFRW; n=10), or a non-blood flow restriction walking control group (CON; n=9). Participants were assessed at baseline, three-weeks and six-weeks for the 30second sit to stand, six-minute walk test, timed up and go, and a modified Queen's College step test. While a rating of perceived exertion (RPE) for training sessions at baseline, three-weeks and six-weeks. RESULTS: BFRW typically resulted in a 2.5-4.5 fold greater improvement in performance on all measures of physical function compared with CON among these older adults. However, RPE was greater for BFRW at all time points (for baseline, three-weeks, six-weeks: 14±0; 11±0; 11±0) compared with CON (8±0; 7±0; 8±0), despite declining across the study for BFRW. CONCLUSIONS: The greater improvement in physical function with blood flow restriction demonstrates how this addition can increase the quality of simple walking exercise for populations that may be contraindicated to heavy-load resistance training.

Corticomotor Excitability is Increased Following an Acute Bout of Blood Flow Restriction Resistance Exercise.

We used transcranial magnetic stimulation (TMS) to investigate whether an acute bout of resistance exercise with blood flow restriction (BFR) stimulated changes in corticomotor excitability (motor evoked potential, MEP) and short-interval intracortical inhibition (SICI), and compared the responses to two traditional resistance exercise methods. Ten males completed four unilateral elbow flexion exercise trials in a balanced, randomized crossover design: (1) heavy-load (HL: 80% one-repetition maximum [1-RM]); (2) light-load (LL; 20% 1-RM) and two other light-load trials with BFR applied; (3) continuously at 80% resting systolic blood pressure (BFR-C); or (4) intermittently at 130% resting systolic blood pressure (BFR-I). MEP amplitude and SICI were measured using TMS at baseline, and at four time-points over a 60 min post-exercise period. MEP amplitude increased rapidly (within 5 min post-exercise) for BFR-C and remained elevated for 60 min post-exercise compared with all other trials. MEP amplitudes increased for up to 20 and 40 min for LL and BFR-I, respectively. These findings provide evidence that BFR resistance exercise can modulate corticomotor excitability, possibly due to altered sensory feedback via group III and IV afferents. This response may be an acute indication of neuromuscular adaptations that underpin changes in muscle strength following a BFR resistance training programme.