The popularity of resistance training has grown immensely over the past 25 years, with extensive research demonstrating that not only is resistance training an effective method to improve neuromuscular function, it can also be equally effective in maintaining or improving individual health status. However, designing a resistance training programme is a complex process that incorporates several acute programme variables and key training principles. The effectiveness of a resistance training programme to achieve a specific training outcome (i.e. muscular endurance, hypertrophy, maximal strength, or power) depends on manipulation of the acute programme variables, these include: (i) muscle action; (ii) loading and volume; (iii) exercise selection and order; (iv) rest periods; (v) repetition velocity; and (vi) frequency. Ultimately, it is the acute programme variables, all of which affect the degree of the resistance training stimuli, that determine the magnitude to which the neuromuscular, neuroendocrine and musculoskeletal systems adapt to both acute and chronic resistance exercise. This article reviews the available research that has examined the application of the acute programme variables and their influence on exercise performance and training adaptations. The concepts presented in this article represent an important approach to effective programme design. Therefore, it is essential for those involved with the prescription of resistance exercise (i.e. strength coaches, rehabilitation specialists, exercise physiologists) to acquire a fundamental understanding of the acute programme variables and the importance of their practical application in programme design.

On two separate occasions, eight subjects controlled speed to run the greatest distance possible in 30 min in a hot, humid environment (ambient temperature 32 degrees C, relative humidity 60%). For the experimental test (precooling), exercise was preceeded by cold-water immersion. Precooling increased the distance run by 304 +/- 166 m (P < 0.05). Precooling decreased the pre-exercise rectal and mean skin temperature by 0.7 degrees C and 5.9 degrees C, respectively (P < 0.05). Rectal and mean skin temperature were decreased up to 20 and 25 min during exercise, respectively (P < 0.05). Mean body temperature decreased from 36.5 +/- 0.1 degrees C to 33.8 +/- 0.2 degrees C following precooling (P < 0.05) and remained lower throughout exercise (P < 0.01) and at the end of exercise (by 0.8 degrees C; P < 0.05). The rate of heat storage at the end of exercise increased from 113 +/- 45 to 249 +/- 55 W.m-2 (P < 0.005). Precooling lowered the heart rate at rest (13%), 5 (9%), and 10 min (10%) exercise (P < 0.05) and increased the end of exercise blood lactate from 4.9 +/- 0.5 to 7.4 +/- 0.9 mmol.L-1 (P < 0.01). The VO2 at 10 and 20 min of exercise and total body sweating are not different between tests. In conclusion, water immersion precooling increased exercise endurance in hot, humid conditions with an enhanced rate of heat storage and decreased thermoregulatory strain.

could be the result of repeated isometric contractions, particularly from the arm and forearm muscles. (Br J Sports Med 1999;33:14-18) Keywords: rock climbing; performance; oxygen uptake; heart rate; lactate Sport climbing is a discipline of rock climbing which is performed indoors and outdoors. Indoor sport climbing is characterised by gymnastic type movements on walls fitted with artificial hand and foot holds and is an internationally contested event. Outdoor sport climbing requires similar movements with the climber guarded from injury during a fall by protection fixed in the rock before ascent. This style of rock climbing and the increased popularity of climbing in recent years have contributed to an increase in the number and difficulty of rock climbing ascents.Although climbers are characterised by low body fat, exceptional power to weight ratios, 1 2 and forearm circulatory adaptations favouring the performance of isometric work, 3 the physiological factors related to sport climbing remain essentially undefined. Previous research suggests that indoor sport climbing is highly anaerobic in nature given the low fraction (∼46%) of running maximum oxygen uptake (Ṽ O 2max ) required for ascents of three to five minutes' duration. 4 However, no study has reported Ṽ O 2 in well trained climbers at diVerent climbing velocities or Ṽ O 2 as peak oxygen uptake (Ṽ O 2climb-peak ) determined during a specific incremental climbing test to exhaustion. Furthermore, no study has reported Ṽ O 2 during an outdoor sport climb or expressed Ṽ O 2 as a percentage of Ṽ O 2climb-peak .Therefore, the purpose of this study was to investigate oxygen consumption during indoor and outdoor sport climbing. During indoor climbing a rock climbing specific ergometer fitted with artificial hand/foot holds was used and climbing velocity incremented until exhaustion to determine Ṽ O 2climb-peak . During the outdoor climb oxygen uptake and the fractional use of a peak oxygen uptake (%Ṽ O 2climb-peak) were investigated. In addition, HR and blood lactate concentrations ([La b ]) were measured. Methods SUBJECTS AND STUDY DESIGNSix men and one woman volunteered as subjects and were all in good health as reported by a medical screening questionnaire. Table 1 gives descriptive characteristics of the subjects. The mean climbing experience of the group was 8.9 (SE 1.2) years, and for individuals the most diYcult outdoor ascent made without preview or fall (on sight ascent) ranged from 6b to 7a. With the numerical scale for climbing diYculty ranging from 5a (novice) to 7c (expert) (UK grading system) the subject sample comprised highly skilled climbers.On one occasion anthropometric measurements were taken, a capillary (finger prick)

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The aim of this study was to establish the effect that pre-cooling the skin without a concomitant reduction in core temperature has on subsequent self-paced cycling performance under warm humid (31 degrees C and 60% relative humidity) conditions. Seven moderately trained males performed a 30 min self-paced cycling trial on two separate occasions. The conditions were counterbalanced as control or whole-body pre-cooling by water immersion so that resting skin temperature was reduced by approximately 5-6 degrees C. After pre-cooling, mean skin temperature was lower throughout exercise and rectal temperature was lower (P < 0.05) between 15 and 25 min of exercise. Consequently, heat storage increased (P < 0.003) from 84.0+/-8.8 W x m(-2) to 153+/-13.1 W x m(-2) (mean +/- s(mean)) after pre-cooling, while total body sweat fell from 1.7+/-0.1 l x h(-1) to 1.2+/-0.1 l h(-1) (P < 0.05). The distance cycled increased from 14.9+/-0.8 to 15.8+/-0.7 km (P < 0.05) after pre-cooling. The results indicate that skin pre-cooling in the absence of a reduced rectal temperature is effective in reducing thermal strain and increasing the distance cycled in 30 min under warm humid conditions.

The aim of this study was to determine whether pre-cooling procedures improve both maximal sprint and sub-maximal work during intermittent-sprint exercise. Nine male rugby players performed a familiarisation session and three testing sessions of a 2 x 30-min intermittent sprint protocol, which consisted of a 15-m sprint every min separated by free-paced hard-running, jogging and walking in 32 degrees C and 30% humidity. The three sessions included a control condition, Ice-vest condition and Ice-bath/Ice-vest condition, with respective cooling interventions imposed for 15-min pre-exercise and 10-min at half-time. Performance measures of sprint time and % decline and distance covered during sub-maximal exercise were recorded, while physiological measures of core temperature (T (core)), mean skin temperature (T (skin)), heart rate, heat storage, nude mass, rate of perceived exertion, rate of thermal comfort and capillary blood measures of lactate [La(-)], pH, Sodium (Na(+)) and Potassium (K(+)) were recorded. Results for exercise performance indicated no significant differences between conditions for the time or % decline in 15-m sprint efforts or the distance covered during sub-maximal work bouts; however, large effect size data indicated a greater distance covered during hard running following Ice-bath cooling. Further, lowered T (core), T (skin), heart rate, sweat loss and thermal comfort following Ice-bath cooling than Ice-vest or Control conditions were present, with no differences present in capillary blood measures of [La(-)], pH, K(+) or Na(+). As such, the ergogenic benefits of effective pre-cooling procedures in warm conditions for team-sports may be predominantly evident during sub-maximal bouts of exercise.

The purpose of this study was to examine and describe the neuromuscular changes associated with fatigue using a self-paced cycling protocol of 60-min duration, under warm, humid conditions. Eleven subjects [mean (SE) age 21.8 (0.8) years; height 174.9 (3.0) cm; body mass 74.8 (2.7) kg; maximum oxygen consumption 50.3 (1.8) ml.kg.min-1] performed one 60-min self-paced cycling time trial punctuated with six 1-min "all out" sprints at 10-min intervals, while 4 subjects repeated the trial for the purpose of determining reproducibility. Power output, integrated electromyographic signal (IEMG), and mean percentile frequency shifts (MPFS) were recorded at the mid-point of each sprint. There were no differences between trials for EMG variables, distance cycled, mean heart rate, and subjective rating of perceived exertion for the subjects who repeated the trial (n = 4). The results from the repeated trials suggest that neuromuscular responses to self-paced cycling are reproducible between trials. The mean heart rate for the 11 subjects was 163.6 (0.71) beats.min-1. Values for power output and IEMG expressed as a percentage of that recorded for the initial sprint decreased during sprints 2-5, with normalised values being 94%, 91%, 87% and 87%, respectively, and 71%, 71%, 73%, and 77%, respectively. However, during the final sprint normalised power output and IEMG increased to 94% and 90% of initial values, respectively. MPFS displayed an increase with time; however, this was not significant (P = 0.06). The main finding of this investigation is the ability of subjects to return power output to near initial values during the final of six maximal effort sprints that were included as part of a self-paced cycling protocol. This appears to be due to a combination of changes in neuromuscular recruitment, central or peripheral control systems, or the EMG signal itself. Further investigations in which changes in multiple physiological systems are assessed systematically are required so that the underlying mechanisms related to the development of fatigue during normal dynamic movements such as cycling can be more clearly delineated.

A relationship between precooling volume and exercise performance seems apparent, as larger surface area coverage augmented subsequent free-paced exercise capacity, in conjunction with greater suppression of physiological load. Maintenance of maximal voluntary contraction with precooling despite increased work output suggests the role of centrally mediated mechanisms in exercise pacing regulation and subsequent performance.