Dr Mike Stone presented on Developing Power, and needs no introduction. The presentation outlined three important concepts, strength, explosive strength, and power. Dr Stone identified the underlying mechanisms of strength as motor control, contractile/structural properties, tissue stiffness, and biomechanical/anthropometric aspects. Strength is closely associated with power production and the “ability” to produce force a critical factor in sports performance. Power may be the most important factor in sport and how it is developed may be critical to sport success. P = F x v; P = F x V; P = F x V – theoretically Power can be achieved with each paradigm.
Training should integrate appropriate stimuli at the right time & consider appropriate fatigue management. Dr Stone emphasised the Block Periodisation model of one fitness phase enhancing the next; Strength Endurance – Basic Strength – Power/Speed Training. Take home message – get athletes strong first, then emphasise power.
Coaches should also consider Long Term Athlete Development, and there appear to be critical age developmental periods to train motor skills, this is highly important as future learning of sport related skills will prove difficult.
Dr Stone also cited recent work of colleagues showing strong relationships between maximum strength, RFD, and power output. Prue Cormie identified that among weak athletes, strength training produced as good or better increases in RFD and power than does power training. Stone also identified that stronger athletes have a more “favourable” neuromuscular profile to serve as a basis for increasing power. Stone referred to Michael Keiner’s recent publication that indicate young athletes with 4-5 years training experience should aim to parallel squat a minimum of 2 x body mass. This performance measure has previously shown to correlate well with sprinting, change of direction, and may have advantages in potentiation training.
Dr Stone finished his presentation by critiquing how to actively develop power production, stating it is difficult to separate exercises into general versus specific. Is the squat a general or specific exercise in the case of a countermovement jump or sprint? Are plyometrics (specific?) any better than squats (general?) and it’s effect on power? Evidence exists that combination training (strength + power) including potentiation complexes can produce better results than either alone. There is also data indicating that strength training + reasonable levels of performance practice = superior results (integrated effect). dr Stone finished with a few take home messages:
1. Many types of skills should be trained early in life, otherwise “window” for optimal training may disappear
2. Learning technique incorrectly may be very difficult to correct
3. Technique is relatively stable in advanced athletes
4. Some data suggests that advanced athletes may be able to adjust their skill level to fit the environmental conditions better than lesser athletes
Adding plyometrics does not always appear to offer benefits over well designed strength training programmes, however:
1. During periods when strength training is low – plyometrics may be valuable
2. As a periodic alternative to heavy strength training or higher volumes of strength training – addition of plyometrics may be valuable
3. Consider the use of complexes using plyometrics as the potentiated exercises
4. Consider the use of combination strength-power training (Olympic movements etc)
Dr Bill Sands is a professor at ETSU and previously Recovery Centre Leader, Head of Sport Biomechanics, and Engineering and Senior Physiologist at the USOC. Dr Sands’ presentation was titled ‘Thinking Sensibly About Recovery’. What is fatigue? Defined as “the compensation of deficit states of an organism and, according to the homeostatic principle, a re-establishment of the initial state”. Another quote which stood out was “training plants the seeds, recovery allows the garden to grow, adaptation bears the fruit”. Dr Sands identified a number of methods available to enhance recovery adaptation; rest, increasing comfort, nutrition, reduction of lymphedema, eliminate injury & illness, change hormonal milieu, and parasympathetic reactivation. It seems that popular methods such as cold immersion, and deep massage can appear to be effective, but the question was asked should we interfere with the “natural” healing process? It was recommended that from years of experience in the field, deep massage should only be conducted if athletes have the following day off training.
Recovery is based on replenishing energy and structural substrates (carbohydrates, protein, timing of replenishment); enhancing rest & relaxation (time off, sleep, naps); and increasing blood flow (heat, cold, heat and cold, hydrotherapy, compression). Dr Sands presented a comparison of massage hours from a time period at the USOC; showing that US Olympic medalists used almost three times less massage hours than non-medalists.
It was concluded that focused recovery adaptation efforts may improve performance a little in the short term (hours). It is more likely that these recovery modalities just make athletes feel better. The main recommendation was to plan training, competitions, and rest better. If you over compete + under train, how do you get better?
Dr John Ivy from the University of Texas Austin gave a detailed presentation on ‘The Importance of the Post Exercise Supplement’. John described the post exercise supplement as the second most important meal of the day. The post exercise environment is low in insulin, cortisol is elevated, muscle & liver glycogen reduced, muscle in a catabolic state, and substrate availability is low. There is a need to turn on protein synthesis, and the quicker this can be stimulated, the faster the adaptations.
One of the primary aims post exercise is to increase blood insulin levels. This will stimulate muscle glucose transport, activate muscle glycogen synthesis, stimulate amino acid transport, and stimulate muscle protein synthesis. Carbohydrate plus protein and/or amino acids are critical for recovery and training adaptation. There is a metabolic window post exercise, which begins to close within 45 minutes following exercise, therefore it is crucial to consume supplements as soon as exercise finishes. Muscle glycogen is not only an important fuel source for exercise, it may also be important for control of protein synthesis and therefore training adaptation. Studies have shown that low glycogen stimulates AMPK activity, and in turn decreases protein synthesis, as an increase in AMPK turns off mTOR (critical to protein synthesis).
Data from Dr Ivy’s lab has shown significant decreases in glycogen storage if the post exercise feed is delayed up to 2 hours post exercise when compared to immediately post exercise (1.5g CHO/kg). There also shows to be no difference in glycogen storage of 1.5g CHO/kg vs 3g CHO/kg. It is recommended ~1.2g CHO/kg & 0.4g PRO/kg post exercise as protein/amino acid ingestion increases glucose transport along with insulin.
Dr Ivy presented studies showing that CHO + PRO supplement reduces myoglobin & plasma CK concentrations (indicators of muscle damage).
Dr Ivy finished with some recommendations for amount of protein in a single dose. 20g of protein (8.6g of essential amino acids) maximally stimulates muscle protein synthesis after resistance exercise in young men. It seems older men require increases up to 40g of protein (16.8g of essential amino acids) to maximally stimulate muscle protein synthesis.
A big thanks to the guys at ETSU for all their help over the few days – Howard Gray, Mark South, Liz Casey, Shawn French, Satoshi Mizuguchi, Tim Suchomel, Meg Stone, Mike Ramsey, Ryan Alexander, Ben Gleason, Hugo Santana, Guy Hornsby, Keith Scruggs, and Mark Chaing.