Does dehydration alter the success rate and technique of three-point shooting in elite basketball?

In order to better inform the effects of dehydration and hydration guidelines, we tested the acute effects of a 2% dehydration protocol on performance and technique of 3-point shooting (3PS) in Elite Basketball players (n = 9). The 3PS technique was monitored by using nanotechnology inertial measurement units positioned onto body joints during the exercise. When dehydrated (−2.1% ± 0.5% of body mass), 7 players experienced a slight decrease (−10.0% ± 19.6%, p = 0.16) in success rate, while RPE increased from 9.1 ± 2.6 to 13.0 ± 2.5 in euhydrated (EUH) and dehydrated (DEH) condition respectively (p = 0.003). DEH slightly altered the 3PS technique as the knee angle increased (p = 0.02) at toe-off time and the hip angle decreased during the 3PS (p = 0.01). The speed of ball release tended to be increased (p = 0.05) in DEH compared to EUH. Data from this study suggest that a 2% dehydration is tolerable for elite Basketball players, although a stronger dehydration might accentuate the effects observed

The impact of sleeping with reduced glycogen stores on immunity and sleep in triathletes.

PURPOSE: We investigated the effects of a 3-week dietary periodization on immunity and sleep in triathletes. METHODS: 21 triathletes were divided into two groups with different nutritional guidelines during a 3-week endurance training program including nine twice a day sessions with lowered (SL group) or maintained (CON group) glycogen availability during the overnight recovery period. In addition to performance tests, sleep was monitored every night. Systemic and mucosal immune parameters as well as the incidence of URTI were monitored every week of the training/nutrition protocol. Two-ways ANOVA and effect sizes were used to examine differences in dependent variables between groups at each time point. RESULTS: The SL group significantly improved 10 km running performance (-1 min 13 s, P < 0.01, d = 0.38), whereas no improvement was recorded in the CON group (-2 s, NS). No significant changes in white blood cells counts, plasma cortisol and IL-6 were recorded over the protocol in both groups. The vitamin D status decreased in similar proportions between groups, whereas salivary IgA decreased in the SL group only (P < 0.05, d = 0.23). The incidence of URTI was not altered in both groups. All participants in both groups went to bed earlier during the training program (SL -20 min, CON -27 min, P < 0.05, d = 0.28). In the SL group, only sleep efficiency slightly decreased by 1.1 % (P < 0.05, d = 0.25) and the fragmentation index tended to increase at the end of the protocol (P = 0.06). CONCLUSION: Sleeping and training the next morning regularly with reduced glycogen availability has minimal effects on selected markers of immunity, the incidence of URTI and sleeping patterns in trained athletes

The effects of repeated sprints on the kinematics of 3-point shooting in basketball

Fatigue modifies the kinematics of various sports-related movements. Basketball induces fatigue, however, the effects of fatigue on the kinematics of shooting have never been studied. This study analysed the effects of fatigue induced by repeated sprints on the kinematics of 3-point shooting (3PS) in young, elite basketball players (U18 level). 3D joint angles were calculated at the maximum and minimum heights of the centre of mass during 3PS, using inertial measurement units (Biomech system, Xsens Technologies BV, Enschede, The Netherlands). Height, velocity and the angle of the ball at the time of release were extrapolated from the wrist joint angles. All players performed four 3PS actions in dynamic conditions before and after a fatigue protocol at 70% of their maximal exercise capacity. The fatigue protocol consisted of a shuttle test with repeated 20-m sprints interspersed with sets of 5 jumps. There was no change in the kinematics of 3PS (p > 0.05), or the ball release variables (p > 0.05) following the fatigue protocol. This suggests that elite basketball players are able to cope with physical fatigue while performing coordinated movements such as 3PS

Retraining and nutritional strategy of an endurance master athlete following hip arthroplasty: a case study

Retraining and resuming competition following surgery is challenging for athletes due to the prolonged period of reduced physical activity and subsequent alteration of body composition and physical performance. This is even more challenging for master athletes who endure the additional effect of aging. Within this context, the purpose of this study was to evaluate the feasibility and benefits that evidence-based nutritional and training recommendations could have on the time course of reconditioning and retraining following hip arthroplasty in an endurance master triathlete. During 38 weeks (from 6 weeks prior to surgery through to the return to competition in week 32), the athlete was provided with detailed training and nutritional recommendations. Dietary intake (via the remote food photographic method), body composition (via DXA), peak oxygen uptake (VO2peak), peak power output (PPO), cycling efficiency (GE), and energy availability (EA) were assessed 6 weeks pre- and 8, 12, 18, 21, and 25-weeks post-surgery. Training load was quantified (via TRIMP score and energy expenditure) daily during the retraining. Total body mass increased by 8.2 kg (attributable to a 3.5–4.6 kg increase in fat mass and lean mass, respectively) between week −6 and 8 despite a reduction in carbohydrate (CHO) intake post-surgery (<3.0 g/kg body mass/day). This was accompanied with a decrease in VO2peak, PPO, and GE due to a drop in training load. From week 7, the athlete resumed training and was advised to increase gradually CHO intake according to the demands of training. Eventually the athlete was able to return to competition in week 32 with a higher PPO, improved VO2peak, and GE. Throughout retraining, EA was maintained around 30 kcal/kg Lean Body Mass/day, protein intake was high (~2 g/kg/day) while CHO intake was periodized. Such dietary conditions allowed the athlete to maintain and even increase lean mass, which represents a major challenge with aging. Data reported in this study show, for the first time, the conditions required to recover and return to endurance competition following hip surgery

Enhanced Endurance Performance by Periodization of CHO Intake: "sleep low" strategy

Purpose: We investigated the effect of a chronic dietary periodization strategy on endurance performance in trained athletes. Methods: 21 triathletes (V[Combining Dot Above]O2max: 58.7 +/- 5.7 mL[middle dot]min-1[middle dot]kg-1) were divided into 2 groups: a "sleep-low" (SL, n = 11) and a control group (CON, n = 10) consumed the same daily carbohydrate (CHO) intake (6 g[middle dot]kg-1[middle dot]d-1) but with different timing over the day to manipulate CHO availability before and after training sessions. The "sleep low" strategy consisted of a 3-week training/diet intervention comprising three blocks of diet/exercise manipulations: 1) "train-high" interval training sessions (HIT) in the evening with high-CHO availability; 2) overnight CHO restriction ("sleeping-low"), and 3) "train-low" sessions with low endogenous and exogenous CHO availability. The CON group followed the same training program but with high CHO availability throughout training sessions (no CHO restriction overnight, training sessions with exogenous CHO provision). Results: There was a significant improvement in delta efficiency during submaximal cycling for SL versus CON (CON: +1.4 +/- 9.3 %, SL: +11 +/- 15 %, P<0.05). SL also improved supra-maximal cycling to exhaustion at 150% of peak aerobic power (CON: +1.63 +/- 12.4 %, SL: +12.5 +/- 19.0 %; P = 0.06) and 10 km running performance (CON: -0.10 +/- 2.03 %, SL: -2.9 +/- 2.15 %; P < 0.05). Fat mass was decreased in SL (CON: -2.6 +/- 7.4; SL: -8.5 +/- 7.4 %PRE, P < 0.01), but not lean mass (CON: -0.22 +/- 1.0; SL: -0.16 +/- 1.7 %PRE). Conclusion: Short-term periodization of dietary CHO availability around selected training sessions promoted significant improvements in submaximal cycling economy, as well as supra-maximal cycling capacity and 10 km running time in trained endurance athletes

Effect of dehydration on performance and technique of three-point shooting in Elite Basketball.

Basketball play is classically accompanied with a significant loss of body water with a potential negative impact on both physical and cognitive performance 1. Very few studies have examined the impact of dehydration on biomechanical adjustments required to score in basketball, though joints angles, the position of the centre of mass and ball release parameters (i.e. height, release speed and angle) are among the best predictive factors of success in basketball shooting 2. Dehydration might alter the biomechanical requirements of successful shots and especially three-point shots (3PS) which generate 16% of points scored during a match. However, only 35% of 3PS are successful in game. Within this framework we analysed the effects of a controlled dehydration protocol on the success and technique of 3PS in elite basketball players. Changes in shooting technique were analysed through changes in body kinematics (i.e. 3D angles of the ankle, knee, hip, shoulder, elbow and wrist, and the height of the centre of mass) and ball release parameters (i.e. height, velocity and angle of the ball at release) of 3PS in a dynamic playing condition

Three weeks of a home-based "sleep low-train low" intervention improves functional threshold power in trained cyclists: A feasibility study.

BACKGROUND: "Sleep Low-Train Low" is a training-nutrition strategy intended to purposefully reduce muscle glycogen availability around specific exercise sessions, potentially amplifying the training stimulus via augmented cell signalling. The aim of this study was to assess the feasibility of a 3-week home-based "sleep low-train low" programme and its effects on cycling performance in trained athletes. METHODS: Fifty-five trained athletes (Functional Threshold Power [FTP]: 258 ± 52W) completed a home-based cycling training program consisting of evening high-intensity training (6 × 5 min at 105% FTP), followed by low-intensity training (1 hr at 75% FTP) the next morning, three times weekly for three consecutive weeks. Participant's daily carbohydrate (CHO) intake (6 g·kg-1·d-1) was matched but timed differently to manipulate CHO availability around exercise: no CHO consumption post- HIT until post-LIT sessions [Sleep Low (SL), n = 28] or CHO consumption evenly distributed throughout the day [Control (CON), n = 27]. Sessions were monitored remotely via power data uploaded to an online training platform, with performance tests conducted pre-, post-intervention. RESULTS: LIT exercise intensity reduced by 3% across week 1, 3 and 2% in week 2 (P < 0.01) with elevated RPE in SL vs. CON (P < 0.01). SL enhanced FTP by +5.5% vs. +1.2% in CON (P < 0.01). Comparable increases in 5-min peak power output (PPO) were observed between groups (P < 0.01) with +2.3% and +2.7% in SL and CON, respectively (P = 0.77). SL 1-min PPO was unchanged (+0.8%) whilst CON improved by +3.9% (P = 0.0144). CONCLUSION: Despite reduced relative training intensity, our data demonstrate short-term "sleep low-train low" intervention improves FTP compared with typically "normal" CHO availability during exercise. Importantly, training was completed unsupervised at home (during the COVID-19 pandemic), thus demonstrating the feasibility of completing a "sleep low-train low" protocol under non-laboratory conditions

Environmental heat stress offsets adaptation associated with carbohydrate periodization in trained male triathletes

Purpose: Carbohydrate (CHO) intake periodization via the sleep low train low (SL-TL) diet–exercise model increases fat oxidation during exercise and may enhance endurance-training adaptation and performance. Conversely, training under environmental heat stress increases CHO oxidation, but the potential of combined SL-TL and heat stress to enhance metabolic and performance outcomes is unknown. Methods: Twenty-three endurance-trained males were randomly assigned to either control (n = 7, CON), SL-TL (n = 8, SLTemp) or SL-TL + heat stress (n = 8, SLHeat) groups and prescribed identical 2-week cycling training interventions. CON and SLTemp completed all sessions at 20°C, but SLHeat at 35°C. All groups consumed matched CHO intake (6 g·kg−1·day−1) but timed differently to promote low CHO availability overnight and during morning exercise in both SL groups. Submaximal substrate utilization was assessed (at 20°C), and 30-min performance tests (at 20 and 35°C) were performed Pre-, Post-, and 1-week post-intervention (Post+1). Results: SLTemp improved fat oxidation rates at 60% MAP (~66% VO2peak) at Post+1 compared with CON (p < 0.01). Compared with SLTemp, fat oxidation rates were significantly lower in SLHeat at Post (p = 0.02) and Post+1 (p < 0.05). Compared with CON, performance was improved at Post in SLTemp in temperate conditions. Performance was not different between any groups or time points in hot conditions. Conclusion: SL-TL enhanced metabolic adaptation and performance compared with CON and combined SL-TL and heat stress. Additional environmental heat stress may impair positive adaptations associated with SL-TL

Effects of Post-Exercise Protein Intake on Muscle Mass and Strength During Resistance Training: is There an Optimal Ratio Between Fast and Slow Proteins?

While effects of the two classes of proteins found in milk (i.e. soluble proteins, including whey, and casein) on muscle protein synthesis have been well investigated after a single bout of resistance exercise (RE), the combined effects of these two proteins on the muscle responses to resistance training (RT) have not yet been investigated. Therefore, the aim of this study was to examine the effects of protein supplementation varying by the ratio between milk soluble proteins (fast-digested protein) and casein (slow-digested protein) on the muscle to a 9-week RT program. In a double-blind protocol, 31 resistance-trained men, were assigned to 3 groups receiving a drink containing 20g of protein comprising either 100% of fast protein (FP(100), n=10), 50% of fast and 50% of slow proteins (FP(50), n=11) or 20% of fast protein and 80% of casein (FP(20), n=10) at the end of training bouts. Body composition (DXA), and maximal strength in dynamic and isometric were analyzed before and after RT. Moreover, blood plasma aminoacidemia kinetic after RE was measured. The results showed a higher leucine bioavailability after ingestion of FP(100) and FP(50) drinks, when compared with FP(20) (p<0.05). However, the RT-induced changes in lean body mass (p<0.01), dynamic (p<0.01), and isometric muscle strength (p<0.05) increased similarly in all experimental groups. To conclude, compared to the FP(20) group, the higher rise in plasma amino acids following the ingestion of FP(100) and FP(50) did not lead to higher muscle long-term adaptations

Acute heat stress amplifies exercise‐induced metabolomic perturbations and reveals variation in circulating amino acids in endurance‐trained males

Using untargeted metabolomics, we aimed to characterise the systemic impact of environmental heat stress during exercise. Twenty-three trained male triathletes (◂◽.▸ = 64.8 ± 9.2 ml kg min−1) completed a 30-min exercise test in hot (35°C) and temperate (21°C) conditions. Venous blood samples were collected immediately pre- and post-exercise, and the serum fraction was assessed via untargeted 1H-NMR metabolomics. Data were analysed via uni- and multivariate analyses to identify differences between conditions. Mean power output was higher in temperate (231 ± 36 W) versus hot (223 ± 31 W) conditions (P 0.05). Environmental heat stress increased glycolytic metabolite abundance and led to distinct alterations in the circulating amino acid availability, including increased alanine, glutamine, leucine and isoleucine. The data highlight the need for additional exercise nutrition and metabolism research, specifically focusing on protein requirements for exercise under heat stress