A strong foundation in physical conditioning and sport-specific experience, in addition to a bespoke and periodized training and nutrition program, are essential for athlete development. Once these underpinning factors are accounted for, and the athlete reaches a training maturity and competition level where marginal gains determine success, a role may exist for the use of evidence-based performance supplements. However, it is important that any decisions surrounding performance supplements are made in consideration of robust information that suggests the use of a product is safe, legal, and effective. The following review focuses on the current evidence-base for a number of common (and emerging) performance supplements used in sport. The supplements discussed here are separated into three categories based on the level of evidence supporting their use for enhancing sports performance: (1) established (caffeine, creatine, nitrate, beta-alanine, bicarbonate); (2) equivocal (citrate, phosphate, carnitine); and (3) developing. Within each section, the relevant performance type, the potential mechanisms of action, and the most common protocols used in the supplement dosing schedule are summarized.

These results suggest that "higher may not be better," as a simulated altitude of 4000 m may potentially blunt absolute training quality. Therefore, it is recommended that a moderate simulated altitude (2000-3000 m) be employed when implementing intermittent hypoxic repeat-sprint training for team-sport athletes.

Scott, BR, Peiffer, JJ, and Goods, PSR. The effects of supplementary low-load blood flow restriction training on morphological and performance-based adaptations in team sport athletes. J Strength Cond Res 31(8): 2147-2154, 2017-Low-load resistance training with blood flow restriction (BFR) may be a method to enhance muscular development even in trained athletes. This study aimed to assess whether supplemental low-load BFR training can improve muscle size, strength, and physical performance characteristics in team sport athletes. Twenty-one semiprofessional Australian football athletes were assessed for 3-repetition maximum (3RM) and muscular endurance in the back squat, vastus lateralis muscle architecture, and performance in sprint and vertical jump tasks. Participants then undertook a 5-week training program, consisting of normal high-load resistance training supplemented by low-load squats with (LLBFR) or without (LL) BFR. Participants also performed regular conditioning and football training during this period. After the training intervention, participants again completed the pretraining testing battery. Squat 3RM and endurance increased from pretraining levels in both LL (3RM = 12.5% increase; endurance = 24.1% increase; p ≤ 0.007) and LLBFR (3RM = 12.3% increase; endurance = 21.2% increase; p = 0.007) groups, though there were no between-group differences. No post-training changes were observed for muscle architecture, or performance in sprinting and jumping tasks. Although squat 3RM and endurance performance increased in both groups, adding BFR during supplemental exercise did not enhance these responses. Similarly, there were no large differences in the assessments of sprint, acceleration, and jumping performance between the groups after training. These findings suggest that although LLBFR did not negatively affect adaptive responses to resistance training, this training strategy may not provide added benefit for healthy Australian football athletes already undertaking a rigorous training schedule.

With minimal costs and travel constraints for athletes, the “living low-training high” (LLTH) approach is becoming an important intervention for modern sport. The popularity of the LLTH model of altitude training is also associated with the fact that it only causes a slight disturbance to athletes' usual daily routine, allowing them to maintain their regular lifestyle in their home environment. In this perspective article, we discuss the evolving boundaries of the LLTH paradigm and its practical applications for athletes. Passive modalities include intermittent hypoxic exposure at rest (IHE) and Ischemic preconditioning (IPC). Active modalities use either local [blood flow restricted (BFR) exercise] and/or systemic hypoxia [continuous low-intensity training in hypoxia (CHT), interval hypoxic training (IHT), repeated-sprint training in hypoxia (RSH), sprint interval training in hypoxia (SIH) and resistance training in hypoxia (RTH)]. A combination of hypoxic methods targeting different attributes also represents an attractive solution. In conclusion, a growing number of LLTH altitude training methods exists that include the application of systemic and local hypoxia stimuli, or a combination of both, for performance enhancement in many disciplines.