Background The health benefits of 150 min a week of moderate-to-vigorous-intensity physical activity (MVPA) in older adults, as currently recommended, are well established, but the suggested dose in older adults is often not reached. Objectives We aimed to determine whether a lower dose of MVPA was effective in reducing mortality, in participants older than 60 years. Methods The PubMed and Embase databases were searched from inception to February 2015. Only prospective cohorts were included. Risk ratios of death were established into four doses based on weekly Metabolic Equivalent of Task (MET)-minutes, defined as inactive (reference), low (1–499), medium (500–999) or high (≥1000). Data were pooled and analysed through a random effects model using comprehensive meta-analysis software. Results Of the 835 reports screened, nine cohort studies remained, totalling 122 417 participants, with a mean follow-up of 9.8±2.7 years and 18 122 reported deaths (14.8%). A low dose of MVPA resulted in a 22% reduction in mortality risk (RR=0.78 (95% CI 0.71 to 0.87) p<0.0001). MVPA beyond this threshold brought further benefits, reaching a 28% reduction in all-cause mortality in older adults who followed the current recommendations (RR=0.72 (95% CI 0.65 to 0.80) p<0.0001) and a 35% reduction beyond 1000 MET-min per week (RR=0.65 (95% CI 0.61 to 0.70) p<0.0001). Conclusions A dose of MVPA below current recommendations reduced mortality by 22% in older adults. A further increase in physical activity dose improved these benefits in a linear fashion. Older adults should be encouraged to include even low doses of MVPA in their daily lives.

Information about the influence of different practice levels on physical characteristics of a large number of soccer players is lacking. Therefore we assessed muscular strength and anaerobic power of elite, subelite and amateur soccer players to clarify what parameters distinguish the top players from the less successful. We tested 95 soccer players from the French first division (elite), second division (subelite), and amateurs and determined the isokinetic strength of the knee extensor and flexor muscles at angular velocities from - 120 ° · s^-1 to 300 ° · s^-1. Vertical jump, 10 m sprint, 30 m sprint and maximum ball speed during shooting were also measured. The elite players had higher knee flexor torque than the amateurs at all angular velocities (p < 0.05), except at 300 ° · s^-1. The hamstring/quadriceps ratios proposed with two different methods were significantly lower in the amateur group than in the elite group (p < 0.05), except at 300 ° · s^-1. Maximum ball speed during shooting and speed over 30 m sprint were not different between elite, subelite, and amateur players while speed over a 10 m sprint was significantly slower in amateur players and faster in the elite group (p < 0.05). Although performance in soccer is not determined only by measurable variables, professional players differ from amateurs in terms of knee flexor muscle strength and short-distance sprinting speed. Based on these findings we conclude that hamstring strength is extremely important in soccer players for joint stabilization during various tasks, notably in eccentric action. Further, short-sprinting performance may mirror actual game situations at high level and could be an important determinant of match-winning actions.

This study analyzes stroke phases and arm and leg coordination during front crawl swimming as a function of swim velocity and performance level. Forty-three swimmers constituted three groups based on performance level. All swam at three different swim velocities, corresponding to the paces appropriate for the 800 m, 100 m, and 50 m. The different stroke phases and the arm and leg coordination were identified by video analysis. Arm coordination was quantified using a new index of coordination (IdC), which expresses the three major modalities opposition, catch-up and superposition. Opposition, where one arm begins the pull phase when the other is finishing the push phase; catch up, which has a lag time (LT) between propulsive phases of the two arms; and superposition, which describes an overlap in the propulsive phases. The IdC is an index which characterizes coordination patterns by measure of LT between propulsive phases of each arm. The most important results showed that duration of the propulsive phases (B + C) increased significantly with increasing velocity: 43.1 ± 3.3 % for V800; 46.5 ± 3 % for V100 and 49 ± 3 % for V50. The arm and leg synchronization was modified in the sense of an increase in six-beat kick. The IdC increased significantly with velocity: IdCV800 = - 7.6 ± 6.4 %; IdCV100 = - 3.2 ± 5.1 % and IdCV50 = - 0.9 ± 5.6 %. IdC increased also significantly with performance level: IdCG3 = - 6.07 ± 5.3 %; IdCG2 = - 3.9 ± 4.2 % and IdCG1 = - 1.76 ± 5.6 % for the mean of the 3 velocity. The two extreme IdC were IdCG3V800 = - 9.4 ± 5.4 % and IdCG1V50 = + 2.53 ± 4.4 %.

The relationships between the mean intensity of a training season, training volume and frequency, and the variations in performance were studied in a group of 18 elite swimmers. Additionally, differences between the swimmers who improved their personal record of the previous year during the follow-up training season (G1R, n = 8) and those who did not (GNI, n = 10) were investigated. The improvement in performance during the follow-up season was significantly correlated with the mean intensity of the training season (r = 0.69, p < 0.01), but not with training volume or frequency. The performance improvement during the follow-up season was negatively related to the initial performance level (r = 0.90, p < 0.01). The decline in performance during detraining from the previous year was less for the GIR than for the GNI (6.21 ± 2.30% vs. 9.79 ± 2.18%, p < 0.01). The present findings suggest that training intensity is the key factor in performance improvement in a group of elite swimmers. Factors such as previous detraining and initial performance level could jeopardize success in spite of a good adaptation to training. Key words: intensity, detraining, dry land training, blood lactate, exercise

Aim:To determine if there are correlations between the physical fitness of young soccer players assessed by field and laboratory testing.Methods:Thirty four male soccer players took part in the study (mean (SD) age 17.5 (1.1) years, height 177.8 (6.7) cm, weight 70.5 (6.4) kg). Maximal oxygen uptake (Vo₂max) during treadmill running and vertical jump height on a force platform were measured in the laboratory. Field tests consisted of a soccer specific endurance test (Bangsbo test) and 30 m sprint with 10 m lap times.Results:The Bangsbo test correlated with the lowest velocity associated with Vo₂max(vVo₂max;R² = 0.55, p<0.001), but not with Vo₂max. Sprint times at 30 m and 20 m were related to peak extension velocity and peak extension force measured during vertical jumping, but not to vertical jump height per se. The jumping force and velocity could explain 46% of the 30 m sprint performance (R² = 0.46, p<0.001).Conclusion:The Bangsbo test and 30 m sprint test correlate withvVo₂maxand vertical jump force and velocity respectively. The Bangsbo test does not give a good estimate of Vo₂maxin young soccer players.

This study investigated the effect of training on performance and assessed the response to taper in elite swimmers (N = 18), using a mathematical model that links training with performance and estimates the negative and positive influences of training, NI and PI. Variations in training, performance, NI, and PI were studied during 3-, 4-, and 6-wk tapers. The fit between modeled and actual performance was significant for 17 subjects; r² ranged from 0.45 to 0.85, P < 0.05. Training was progressively reduced during tapers. Performance improved during the first two tapers: 2.90 ± 1.50% (P < 0.01) and 3.20 ± 1.70% (P < 0.01). Performance improvement in the third taper was not significant (1.81 ± 1.73%). NI was reduced during the first two tapers (P < 0.01 and P < 0.05, respectively), but not during the third. PI did not change significantly during tapers. Thus, the present results show that the model used is a valuable method to describe the effects of training on performance. Performance improvement during taper was attributed to a reduction in NI. PI did not improve with taper, but it was not compromised by the reduced training periods.