Sports Coach Logo Sports Coach Logo

            topics

 

text Translator

 

 

site search facility

 


 

 


 

What the experts say

Nigel Hetherington reviews the latest research material relating to coaching, exercise physiology and athletic development.

Firing orders can be effective!

Specific sequences of muscle coordination exist in movements of every sport. In particular, sports involving repetitive movement patterns such as rowing may rely more heavily on coordinated muscle contraction sequencing in order to produce optimal performance. Fatigue patterns of the major muscles engaged during the rowing stroke in rowers of varying abilities were studied[1] during a 6-minute continuous maximal rowing effort on a Concept II rowing ergometer. Sixteen male rowers were categorized into 5 groups based on years of training and their average pace of the 6-minute continuous maximal rowing effort. Continuous surface electromyography signals, recorded from 8 different muscle groups, were used to investigate the influence of local muscle fatigue on optimal muscle coordination sequences during the rowing exercise. Rowers who performed better on the ergometer test and had more rowing experience tended to portray muscle recruitment patterning, which alternately emphasized different major muscle groups in a form of sharing of workload. This sharing allowed mean peak frequency restitution to take place in some muscles, while others took on more of the workload. The muscles of rowers with less experience and lower levels of performance did not appear to exhibit this same phenomenon known as biodynamic compensation. If coaches have a clearer picture of the fatigue patterns and recruitment strategies occurring in their athletes during a maximal effort row, strength training program adaptations could be made to compensate for weaker areas, which may assist rowers in attaining and sustaining more optimal patterns and strategies throughout the exercise effort.

Considerations for maximizing strength training

The influences of age and gender were studied[2] on regional changes in 1RM strength using 10 young men (20-30 years), 8 young women (20-30 years), 11 older men (65-75 years), and 10 older women (65-75 years) before and after a 24-week whole-body strength training program. Changes in 1RM strength were analyzed for each individual exercise, as well as by calculating a total body score (TBS), an upper body score (UBS), and a lower body score (LBS). The effect of age and gender on changes in 1RM strength was analyzed statistically. When changes in strength for individual exercises were analyzed, the chest press, lat pull-down, shoulder press, and triceps pushdown were affected by both age and gender, while the biceps curls were only influenced by age. For the lower body, the leg press changes in 1RM strength were influenced by age, while leg extension was influenced by gender. Total body score, UBS, and LBS showed significant increases with 24 weeks of ST in all cases. Changes in TBS and UBS were affected by age and gender. Younger subjects showed a greater increase in strength than older subjects, and men showed a greater increase in strength compared with women. Changes in LBS were affected by age, with younger subjects showing a greater increase in strength compared with the older subjects, but not by gender. These data indicate that regional increases in strength are differentially affected by age and gender.

Bodybuilders, athletes, and recreational lifters select a grip width during the bench press that they believe will produce a greater force output. Research[3] has demonstrated that a wide grip (>1.5 shoulder width) may increase the risk of shoulder injury, including anterior shoulder instability, atraumatic osteolysis of distal clavicle, and pectoralis major rupture. Reducing grip width to 1.5 biacromial width appears to reduce this risk and does not affect muscle recruitment patterns, only resulting in a ±5% difference in one repetition maximum.

Jump in plyometrics understanding

Planning of the intensity and volume of plyometric exercises are usually based simply upon estimations rather than empirical evidence. A study[4] sought to quantify a variety of such exercises based on forces placed upon the knee. Six plyometrically trained athletes performed depth jumps from 46 and 61 cm, a pike jump, tuck jump, single-leg jump, countermovement jump, squat jump, and a squat jump holding dumbbells equal to 30% of their 1RM. Ground reaction forces were recorded using a force plate and video analysis of markers placed on the left hip, knee, lateral malleolus (head of fibula or 'ankle bone'), and fifth metatarsal were used to estimate rate of eccentric force development, peak ground reaction forces, ground reaction forces relative to body weight, knee joint reaction forces, and knee joint reaction forces relative to body weight for each plyometric exercise. Results indicated that there were quantitative differences between plyometric exercises in the rate of force development during landing and the forces placed on the knee, though peak ground reaction forces associated with landing may not differ.

Supplements

A study[5] measured the effects creatine (Cr) loading on thermoregulatory responses during intermittent sprint exercise in a hot/humid environment. 10 acclimatized men performed 2 familiarization sessions of an exercise test consisting of a 30-minute low-intensity warm-up followed by 6 x 10 second maximal sprints on a cycle ergometer in the heat (35°C, 60% relative humidity). Subjects then participated in 2 different weeks of supplementation. The first week, subjects ingested 5g of a placebo (P, maltodextrin) in 4 flavored drinks (20 g total) per day for 6 days and were retested on day 7. The second week was similar to the first except a similar dose (4 x 5 g/day) of creatine monohydrate (Cr) replaced maltodextrin in the flavored drinks. Six days of Cr supplementation produced a significant increase in body weight (+1.30 ± 0.63 kg), whereas the P did not (+0.11 ± 0.52 kg). Compared to pre-exercise measures, the exercise test in the heat produced a significant increase in core temperature, a loss of body water determined by body weight change during exercise, and a relative change in plasma volume (%PVC); however, these were not significantly different between P and Cr. Sprint performance was enhanced by Cr loading. Peak power and mean power were significantly higher during the intermittent sprint exercise test following 6 days of Cr supplementation. It appears that ingestion of Cr for 6 days does not produce any different thermoregulatory responses to intermittent sprint exercise but may augment sprint exercise performance in the heat.

Studies have demonstrated increases in peak torque (PT) and decreases in acceleration time (ACC) after only 2 days of resistance training, and other studies have reported improvements in isokinetic performance after 5 days of creatine supplementation. Consequently, there may be a combined benefit of creatine supplementation and short-term resistance training for eliciting rapid increases in muscle strength, which may be important for short-term rehabilitation and return-to-play for previously injured athletes. A study[6] examined the effects of 3 days of isokinetic resistance training combined with 8 days of creatine monohydrate supplementation on the vastus lateralis (outer quadriceps) during maximal concentric isokinetic leg extension muscle actions. Subjects were randomly assigned to either the creatine or placebo group. Two servings per day were administered on days 1-6, with only 1 serving on days 7-8. Before (day 1) and after (day 9) the prescribed resistance training, maximal voluntary concentric isokinetic leg extensions were performed on a dynamometer. The results indicated that 3 days of isokinetic resistance training was sufficient to elicit small, but significant, improvements in peak strength (PT) and ACC for both groups. Although the greater relative improvements in PT and ACC for the CRE group were not statistically significant, these findings may be useful for rehabilitation or strength and conditioning professionals who may need to rapidly increase the strength of a patient or athlete within 9 days.

An investigation[7] examined the effects of a protease supplement on selected markers of muscle damage and delayed-onset muscle soreness (DOMS). Subjects were tested for unilateral isometric forearm flexion strength, hanging joint angle, relaxed arm circumference, subjective pain rating, and plasma creatine kinase activity and myoglobin concentration. The testing occurred before, immediately after, and 24, 48 and 72 hours after a bout of eccentric exercise. During these tests, the subjects in one group ingested a protease supplement. The subjects in the other group took microcrystalline cellulose (placebo). The results provided initial evidence that the protease supplement may be useful for reducing strength loss immediately after eccentric exercise and for aiding in short-term strength recovery. The protease supplement had no effect, however, on the perception of pain associated with DOMS or the blood markers of muscle damage.

Investigators have reported improved endurance performance and attenuated post-exercise muscle damage with carbohydrate-protein beverages (CHO+P) versus carbohydrate-only beverages (CHO). However, these benefits have been demonstrated only when CHO+P was administered in beverage-form, and exclusively in male subjects. A study[8] determined if an oral CHO+P gel improved endurance performance and post-exercise muscle damage compared to a CHO gel, and determined if responses were similar between genders.

Thirteen trained cyclists completed two timed cycle-trials to volitional exhaustion at 75% of O2peak. At 15-minute intervals throughout these rides, subjects received CHO or CHO+P gels, which were matched for carbohydrate content. Subjects rode 13% longer when utilizing the CHO+P gel (116.6 ± 28.5 minutes) versus the CHO gel (102.8 ± 25.0 minutes). In addition, men (101.8 ± 24.6; 114.8 ± 26.2) and women (104.4 ± 28.6; 119.6 ± 34.9) responded similarly to the CHO and CHO+P trials, with no significant treatment-by-gender effect. Post exercise creatine kinease (CK) was not significantly different between treatments. However, CK increased significantly following exercise in the CHO trial but not the CHO+P trial. Therefore, to prolong endurance performance and prevent increases in muscle damage, it is recommended that male and female cyclists consume CHO+P gels rather than CHO gels during and immediately following exercise.

These data indicate that carbohydrate supplementation attenuates perceived exertion during prolonged intermittent exercise and recovery.

More on warm-ups

The effect of 6 warm-up protocols, with and without stretches, were studied[9] on 2 different power manoeuvres: a 30-m sprint run and a vertical countermovement jump (CJ). The 6 protocols were: walk plus run (WR); WR plus exercises including small jumps (EJ); WR plus dynamic active stretch plus exercises with small jumps (DAEJ); WR plus dynamic active stretch (DA); WR plus static stretch plus exercises with small jumps (SSEJ); and WR plus static stretch (SS). Subjects performed each of 6 randomly ordered exercise routines prior to randomly ordered sprint and vertical jump field tests; each routine and subsequent test was performed on separate days. The WR protocol produced higher jumps than did SS, and DAEJ produced higher jumps than did SS. There were no significant differences among the 6 protocols on sprint run performance. No significant interaction occurred between gender and protocol. There were significant differences between men and women on CJ and sprint trials; as expected, in general men ran faster and jumped higher than the women did. The data indicate that a warm-up including static stretching may negatively impact jump performance, but not sprint time.

Balance volume and intensity for best results in endurance

A study[10] compared the effect of 2 training programs differing in the relative contribution of training volume; 'clearly below' vs. 'within' the lactate threshold/maximal lactate steady state region on performance in endurance runners. Twelve sub-elite endurance runners (track specialists with cross-country experience) were randomly assigned to a training program emphasizing low-intensity (sub-threshold) (Z1) or moderately high-intensity (between thresholds) (Z2) training intensities. At the start of the study, the subjects performed a maximal exercise test to determine ventilatory (VT) and respiratory compensation thresholds (RCT), which allowed training to be controlled based on heart rate during each training session over a 5-month training period. Subjects performed a simulated 10.4-km cross-country race before and after the training period. Training was quantified based on the cumulative time spent in 3 intensity zones: zone 1 (low intensity; <VT), zone 2 (moderate intensity; between VT and RCT), and zone 3 (high intensity;> RCT). The contribution of total training time spent in zones 1 and 2 was controlled to have relatively more low-intensity training in Z1 (80.5 ± 1.8% and 11.8 ± 2.0%, respectively) than in Z2 (66.8 ± 1.1% and 24.7 ± 1.5%, respectively), whereas the contribution of high-intensity (zone 3) training was similar (8.3 ± 0.7% [Z1] and 8.5 ± 1.0% [Z2]). The magnitude of the improvement in running performance was significantly greater in Z1 (-157 ± 13 seconds) than in Z2 (-121.5 ± 7.1 seconds). These results provide experimental evidence supporting the value of a relatively large percentage of low-intensity training over a long period ( 5 months), provided that the contribution of high-intensity training remains sufficient.

Right down to the core

A review[11] critically examined core stability training to determine useful applications for sports conditioning programs. Based on the current literature, prescription of core stability exercises should vary based on the phase of training and the health status of the athlete. During pre-season and in-season mesocycles, free weight exercises performed while standing on a stable surface are recommended for increases in core strength and power. Free weight exercises performed in this manner are specific to the core stability requirements of sports-related skills due to moderate levels of instability and high levels of force production. Conversely, during postseason and off-season mesocycles, Swiss ball exercises involving isometric muscle actions, small loads, and long tension times are recommended for increases in core endurance. Furthermore, balance board and stability disc exercises, performed in conjunction with plyometric exercises, are recommended to improve proprioceptive and reactive capabilities, which may reduce the likelihood of lower extremity injuries.

Eureka!

And finally, though it may be about peaking for a thrower I thought this statement from a recent paper[12] summed up almost all the physicality based objectives of coaching quite succinctly:

"Specificity is a vital concept in track and field training for the {throwing} events. Specific physiological/performance characteristics can be developed by emphasizing specific training variables. Exercises must be specifically designed for the demands of the event. Effective program design must address energetics, mechanics, and coordination characteristics specific to {throwing}. The goal of final preparation in the competition phase is to develop speed strength and to maximize fitness, to fine-tune skills but minimize fatigue on the day of the competition."


References

  1. So RCH et al. 'Application of surface electromyography in assessing muscle recruitment patterns in a six-minute continuous rowing effort'. J. Strength Cond. Res. 21(3):724-730. 2007
  2. Lemmer JT et al. 'Age and sex differentially affect regional changes in 1 repetition maximum strength' J. Strength Cond. Res. 21(3):731-737. 2007
  3. Green CM and Comfort P 'The Affect of Grip Width on Bench Press Performance and Risk of Injury' Strength and Conditioning Journal: Vol. 29, No. 5, pp. 10-14
  4. Jensen RL and Ebben WP 'Quantifying plyometric intensity via rate of force development, knee joint, and ground reaction forces' J. Strength Cond. Res. 21(3):763-767. 2007
  5. Wright GA et al. 'The effects of creatine loading on thermoregulation and intermittent sprint exercise performance in a hot humid environment' J. Strength Cond. Res. 21(3):655-660. 2007
  6. Cramer JT et al. 'Effects of creatine supplementation and three days of resistance training on muscle strength, power output, and neuromuscular function' J. Strength Cond. Res. 21(3):668-677. 2007
  7. Beck TW et al. 'Effects of a protease supplement on eccentric exercise-induced markers of delayed-onset muscle soreness and muscle damage' J. Strength Cond. Res. 21(3):661-667. 2007
  8. Saunders MJ et al. 'Consumption of an oral carbohydrate-protein gel improves cycling endurance and prevents post-exercise muscle damage' J. Strength Cond. Res. 21(3):678-684. 2007
  9. Vetter RE 'Effects of six warm-up protocols on sprint and jump performance' J. Strength Cond. Res. 21(3):819-823. 2007
  10. Esteve-Lanao J et al. 'Impact of training intensity distribution on performance in endurance athletes' J. Strength Cond. Res. 21(3):943-949. 2007
  11. Willardson JM 'Core stability training: Applications to sports conditioning programs'. J. Strength Cond. Res. 21(3):979-985. 2007
  12. Judge LW 'Developing Speed Strength: In-Season Training Program for the Collegiate Thrower' Strength and Conditioning Journal: Vol. 29, No. 5, pp. 42-54.

Article Reference

This article first appeared in:

  • HETHERINGTON, N. (2007) What the experts say. Brian Mackenzie's Successful Coaching, (ISSN 1745-7513/ 47/ November), p. 15-18

Page Reference

If you quote information from this page in your work then the reference for this page is:

  • HETHERINGTON, N. (2007) What the experts say [WWW] Available from: https://www.brianmac.co.uk/articles/scni47a7.htm [Accessed

About the Author

Nigel Hetherington was the Head Track & Field Coach at the internationally acclaimed Singapore Sports School. He is a former National Performance Development Manager for Scottish Athletics and National Sprints Coach for Wales. Qualified and highly active as a British Athletics level 4 performance coach in all events he has coached athletes to National and International honours in sprints, hurdles as well as a World Record holder in the Paralympic shot. He has 10 years experience as senior coach educator and assessor trainer on behalf of British Athletics. Nigel is also an experienced athlete in sprint (World Masters Championship level) and endurance (3-hour marathon runner plus completed the 24 hour 'Bob Graham Round' ultra-endurance event up and down 42 mountain peaks in the English Lake District). He is a chartered chemist with 26 years' experience in scientific research and publishing.

Related Pages

The following Sports Coach pages provide additional information on this topic: