The effects of resistance training on aerobic and anaerobic power of young boys

A 4-wk interval-type training program incorporating omni-kinetic equipment and stationary cycling elicited an increase in the absolute and relative VO2max of an active group of young boys. The improvement in aerobic function was independent of the training protocols of high velocity-low resistance and low velocity-high resistance. However, the training programs failed to increase anaerobic function as measured by an "all-out" cycle test in which power output was calculated in watts and watts per kilogram for 0- to 15-s and 15- to 30-s work periods. Changes in aerobic and anaerobic functions were independent of physiological maturity as determined by serum testosterone level (ng X dl-1).     

Effect of training on anaerobic threshold, maximal aerobic power and anaerobic performance of preadolescent boys

To evaluate the effect of a 9-week interval training program on aerobic capacity, anaerobic capacity, and indices of anaerobic threshold of preadolescent boys, 28 10.2- to 11.6-year-old boys were tested. The test included laboratory evaluation of anaerobic capacity (Wingate anaerobic test) and evaluation of VO2 max and anaerobic threshold indices from a graded exercise test and measurement of blood lactate. The tests also included a 1200-m run to investigate the relationship of laboratory fitness indices, VO2 max, anaerobic threshold indices, and indices of anaerobic capacity to the performance of the run. It was found that in 10- to 11-year-old boys, a 9-week interval training increased the indices of anaerobic capacity: mean power by 10% and peak power by 14%. No change was found in percent fatigue. The training also increased VO2 max by 7% in absolute terms and by 8%/kg body weight. A significant increase was also found in the running velocity at the anaerobic threshold (running velocity at inflection point of lactate accumulation curve), but in relative terms (percent of VO2 max), the anaerobic threshold decreased by approximately 4.4%. It is concluded that proper training may improve maximal aerobic power and anaerobic capacity of preadolescent boys. It is also concluded that anaerobic threshold measures are less sensitive to the training regimen than VO2 max and that the 1200-m running performance is strongly associated with both aerobic and anaerobic capacities and less with the anaerobic threshold, which in preadolescent boys seems to be higher than in adults.     

Effect of a 13-week aerobic training programme on the maximal power developed during a force-velocity test in prepubertal boys and girls.

The present study was undertaken in order to evaluate the effect of an aerobic training programme on the maximal power (Pmax) developed during a short-term exercise test in prepubertal children. Thirty-three 10-11 year old boys and girls were investigated: 17 (TG) participated twice a week (1 h per session) in a 13-week running programme and 16 (CG) served as a control group. Pmax was measured during a force-velocity test conducted on a friction-loaded cycle ergometer. The force (Fopt) and velocity (Vopt) at which Pmax was obtained were determined. Lower limb muscle mass (LMM) was evaluated by means of dual X-ray absorptiometry. Following training, Pmax increased even when muscle mass change due to the growth process was taken into account (Pmax W: + 23 %, W x kg(-1) LMM: + 18%, p < 0.001). The increase in Fopt was principally responsible for such an improvement since no alteration was noticed for Vopt after training. As for Pmax, Fopt was still greater following training when LMM was taken into account (p < 0.01). Furthermore, no changes were noticed for CG for all variables evaluated during the anaerobic test after the study period. Differences between TG and CG regarding Pmax and Fopt were obtained after training only. In conclusion this study highlights the effectiveness of an aerobic training programme to improve the maximal power during short-term exercise in prepubertal children.     

Effects of resistive training on lipoprotein-lipid profiles: a comparison to aerobic exercise training

A recent surge of cross-sectional and longitudinal studies dealing with resistive training and lipid profiles have produced conflicting results. The majority of cross-sectional studies demonstrate a reduced HDL cholesterol level or elevated total cholesterol to HDL ratio in strength trained athletes as compared with endurance trained athletes. Because of selection biases from many of these studies, there is a lack of control for factors that may influence lipids and lipoproteins, such as age, body composition, diet, and anabolic-androgenic steroid use. Most investigators have reported improved lipoprotein-lipid profiles from resistive training programs. However, many of these studies have design flaws or limitations that make their conclusions questionable. The most serious design flaws include the combination of no control group and only one blood sample taken before and after training, the use of subjects who have low risk profiles, and the lack of control for dietary effects. In a recent study in which we attempted to control for these factors, no changes in lipid profiles were observed after 20 wk of resistive training among individuals at risk for coronary heart disease (CHD). A group serving as reference controls who participated in aerobic-type exercise training during the same time period reduced their plasma triglyceride levels but did not alter their cholesterol or lipoprotein levels. No changes in any lipids or lipoproteins were observed in a group of inactive controls. Thus, resistive training does not appear to alter lipoprotein-lipid profiles among individuals at risk for CHD.     

Metabolic demands of intense aerobic interval training in competitive cyclists

PURPOSE: To investigate the metabolic demands of a single session of intense aerobic interval training in highly trained competitive endurance cyclists. METHODS: Seven cyclists (peak O2 uptake [VO2 peak] 5.14 +/- 0.23 L x min(-1), mean +/-SD) performed 8 x 5 min work bouts at 86 +/- 2% of VO2 peak with 60-s recovery. Muscle biopsies were taken from the vastus lateralis immediately before and after the training session, whereas pulmonary gas exchange and venous blood were sampled at regular intervals throughout exercise. RESULTS: Muscle glycogen concentration decreased from 501 +/- 91 to 243 +/- 51 mmol x kg (-1) dry mass (P < 0.01). High rates of total carbohydrate oxidation were maintained throughout exercise (340 micromol.kg(-1).min(-1)), whereas fat oxidation increased from 16 +/- 8 during the first to 25 +/- 13 micromol x kg(-1) x min(-1) during the seventh work bout (P < 0.05). Blood lactate concentration remained between 5 and 6 mM throughout exercise, whereas muscle lactate increased from 6 +/- 1 at rest to 32 +/- 12 mmol x kg(-1) d.m. immediately after the training session (P < 0.01). Although muscle pH decreased from 7.09 +/- 0.06 at rest to 7.01 +/- 0.03 at the end of the session (P < 0.01), blood pH was similar after the first and seventh work bouts (7.34). Arterial oxygen saturation (% S(P)O2) fell to 95.6 +/- 1% during the first work bout and remained at 94% throughout exercise: the 60-s rest intervals were adequate to restore % S(P)O2) to 97%. CONCLUSION: Highly trained cyclists are able to sustain high steady state aerobic power outputs that are associated with high rates of glycogenolysis and total energy expenditure similar to those experienced during a 60-min competitive ride.     

Muscle structure and aerobic performance capacity in recruit training school

The aerobic performance capacity (VO2 max) and muscle ultrastructural composition was analyzed in 18 subjects undergoing basic training in the Swiss army. Three groups were selected based on their sports activity. Group S contained subjects that had a previous systematic background in sports activities and trained regularly at least three times per week. A second group consisted of subjects that had no previous training and were subjected to an additional, individually adjusted endurance exercise (three times per week) for the first 8 weeks of their service period (group T). The control group (C) had no previous training and followed only the regular military duties. VO2 max was found to be significantly higher in group S at the beginning of the military service. However, VO2 max did not change significantly during the service period in any of the groups, Muscle mitochondria showed a significant change (+19%) only in group T. Heart rate recordings indicated that despite "strenuous" military activity, heart rates rarely reached levels sufficient for an increase in aerobic performance capacity.     

One-year aerobic interval training in outpatients with schizophrenia: A randomized controlled trial

Although aerobic interval training (AIT) is recognized to attenuate the risk of cardiovascular disease (CVD) and premature mortality, it appears that it rarely arrives at patients’ doorsteps. Thus, this study investigated 1-year effects and feasibility of AIT delivered with adherence support in collaborative care of outpatients with schizophrenia. Forty-eight outpatients (28 men, 35 [31-38] (mean [95% confidence intervals]) years; 20 women, 36 [30-41] years) with schizophrenia spectrum disorders (ICD-10) were randomized to either a collaborative care group provided with municipal transportation service and training supervision (walking/running 4 × 4 minutes at ~90% of peak heart rate; HR_peak) 2 d wk⁻¹ at the clinic (TG) or a control group (CG) given 2 introductory AIT sessions and advised to continue training. Directly assessed peak oxygen uptake () increased in the TG after 3 months (2.3 [0.6-4.4] mL kg⁻¹ min⁻¹, Cohen's d = 0.33[−4.63 to 4.30], P = 0.04), 6 months (2.7 [0.5-4.8] mL kg⁻¹ min⁻¹, Cohen's d = 0.42[−4.73 to 4.11], P = 0.02) and 1 year (4.6 [2.3-6.8] mL kg⁻¹ min⁻¹, Cohen's d = 0.70[−4.31 to 4.10], P < 0.001) compared to the CG. One-year cardiac effects revealed higher HR_peak (7 [2-11] b min⁻¹, Cohen's d = 0.34[−8.48 to 8.65], P = 0.01), while peak stroke volume tended to be higher (0.9 [−0.2 to 2.0] mL b⁻¹, Cohen's d = 0.35[−1.62 to 2.01], P = 0.11) in the TG compared to the CG. Conventional risk factors (body weight, waist circumference, blood pressure, and lipids/glucose) remained unaltered in both groups. One-year AIT adherence rates were 15/25 (TG; different from CG: P < 0.001) and 0/23 (CG). AIT was successfully included in long-term collaborative care of outpatients with schizophrenia and yielded improved , advocating this model for aerobic capacity improvement and CVD risk reduction in future treatment.     

The effectiveness of a training programme upon maximum aerobic power.

Forty-two trained and untrained young Chinese subjects of both sexes were employed for this study. Maximal oxygen uptake and anaerobic threshold were measured with the Beckman Metabolic Measurement Cart (MMC) during incremental work test. Skinfold thickness was measured using a skinfold caliper. Body density was calculated with skinfold thickness according to the formula of Suzuki et al (1975). % fat was calculated with the equation given by Brozek et al (1963). % fat of trained subjects was significantly lower than untrained subjects in both sexes. Maximal aerobic power of trained subjects was greater than untrained subjects in both sexes. VO2 at "AT" in trained subjects was greater than untrained subjects in both sexes. Anaerobic threshold might be a valid and useful physiological index for evaluation of physical fitness in various subjects.     

Intraindividual allometric development of aerobic power in 8- to 16-year-old boys

PURPOSE: The aims of this study are two-fold: first, to analyze intraindividual allometric development of aerobic power of 73 boys followed at annual intervals from 8 to 16 yr, and second, to relate scaled aerobic power with level of habitual physical activity and biological maturity status. METHODS: Peak VO2 (treadmill), height, and body mass were measured. Biological maturity was based on age at peak height velocity (PHV) and level of physical activity was based on five assessments between 11 and 15 yr and at 17 yr. Interindividual and intraindividual allometric coefficients were calculated. Multilevel modeling was applied to verify if maturity status and activity explain a significant proportion of peak VO2 after controlling for other explanatory characteristics. RESULTS: At most age levels, interindividual allometry coefficients for body mass exceed k = 0.750. Intraindividual coefficients of peak VO2 by body mass vary widely and range from k' = 0.555 to k' = 1.178. Late maturing boys have smaller k' coefficients than early maturing boys. CONCLUSION: Peak VO2 is largely explained by body mass, but activity level and its interaction with maturity status contribute independently to peak VO2 even after adjusting for body mass.     

Influence of continuous and interval training on oxygen uptake on-kinetics

PURPOSE: To examine the relative effectiveness of moderate-intensity continuous training and high-intensity interval training on pulmonary O2 uptake (VO2) kinetics at the onset of moderate- and severe-intensity cycle exercise in previously sedentary subjects. METHODS: Twenty-three healthy subjects (11 males; mean +/- SD age 24 +/- 5 yr; VO2peak 34.3 +/- 5.5 mL x kg(-1) x min(-1)) were assigned to one of three groups: a continuous training group that completed three to four sessions per week of 30-min duration at 60% VO2peak (LO); an interval training group that completed three to four sessions per week involving 20 x 1-min exercise bouts at 90% VO2peak separated by 1-min rest periods (HI); or a control group (CON). Before and after the 6-wk intervention period, all subjects completed a series of step exercise tests to moderate and severe work rates during which pulmonary VO2 was measured breath-by-breath. RESULTS: ANOVA revealed that continuous and interval training were similarly effective in reducing the phase II VO2 time constant during moderate (LO: from 31 +/- 8 to 23 +/- 5 s; HI: from 32 +/- 9 to 21 +/- 4 s; both P < 0.05; CON: from 30 +/- 6 to 29 +/- 7 s; NSD) and severe exercise (LO: from 35 +/- 6 to 24 +/- 7 s; HI: from 32 +/- 11 to 24 +/- 7 s; both P < 0.05; CON: from 27 +/- 7 to 25 +/- 5 s; NSD) and in reducing the amplitude of the VO2 slow component (LO: from 0.38 +/- 0.10 to 0.29 +/- 0.09 L x min(-1); HI: from 0.41 +/- 0.28 to 0.30 +/- 0.28 L x min(-1); both P < 0.05; CON: from 0.54 +/- 0.22 to 0.66 +/- 0.38 L.min; NSD). CONCLUSIONS: Six weeks of low-intensity continuous training and high-intensity interval training were similarly effective in enhancing VO2 on-kinetics following step transitions to moderate and severe exercise in previously untrained subjects.     

Adaptations to aerobic interval training: interactive effects of exercise intensity and total work duration

To compare the effects of three 7‐week interval training programs varying in work period duration but matched for effort in trained recreational cyclists. Thirty‐five cyclists (29 male, 6 female, VO_2peak 52 ± 6 mL kg/min) were randomized to four training groups with equivalent training the previous 2 months (～6 h/wk, ～1.5 int. session/wk). Low only (n=8) trained 4–6 sessions/wk at a low‐intensity. Three groups (n=9 each) trained 2 sessions/wk × 7 wk: 4 × 4 min, 4 × 8 min, or 4 × 16 min, plus 2–3 weekly low‐intensity bouts. Interval sessions were prescribed at the maximal tolerable intensity. Interval training was performed at 88 ± 2, 90 ± 2, and 94 ± 2% of HR_peak and 4.9, 9.6, and 13.2 mmol/L blood lactate in 4 × 16, 4 × 8, and 4 × 4 min groups, respectively (both P<0.001). 4 × 8min training induced greater overall gains in VO₂peak, power@VO₂peak, and power@4 mM bLa‐ (Mean ± 95%CI): 11.4 (8.0–14.9), vs 4.2 (0.4–8.0), 5.6 (2.1–9.1), and 5.5% (2.0–9.0) in Low, 4 × 16, and 4 × 4 min groups, respectively (P<0.02 for 4 × 8 min vs all other groups). Interval training intensity and accumulated duration interact to influence the adaptive response. Accumulating 32 min of work at 90% HR max induces greater adaptive gains than accumulating 16 min of work at ～95% HR max despite lower RPE.     

Sensitivity of maximal aerobic power to training is genotype-dependent

Ten pairs of monozygotic twins of both sexes were submitted to a 20-wk endurance-training program, four and five times per week, 40 min per session, at an average of 80% of the maximal heart rate reserve. Testing and training were performed on cycle ergometers. Maximal aerobic power (MAP in ml O2 X min-1 X kg-1) and ventilatory aerobic (VAT) and anaerobic (VANT) thresholds (ml O2 X min-1 X kg-1) were measured before and after the training program, as well as during the 7th and 14th week to adjust training to changes in maximal heart rate. Considering the 20 individuals as a group, training significantly (P less than or equal to 0.01) increased MAP (from 44 +/- 6 to 50 +/- 6), VAT (25 +/- 3 to 30 +/- 4), and VANT (36 +/- 5 to 42 +/- 6). Thus, MAP improved by 12% of the pre-test value, while mean changes in VAT and VANT reached 20% and 17%, respectively. There were, however, considerable interindividual differences in training gains as exemplified by a range of about 0% to 41% for MAP. Differences in the MAP response to training were not distributed randomly among the twin pairs. Thus, intraclass correlations computed with the amount of improvement in MAP (ml O2 X min-1 X kg-1) reached 0.74 (P less than 0.01) indicating that members of the same twin-pair yielded approximately the same response to training. The same coefficient reached 0.43 and 0.24 for VAT and VANT, respectively (P greater than 0.05). These results suggest that there are considerable individual differences in the adaptive capacity to short-term endurance training. Moreover, sensitivity of maximal aerobic power to such training is largely genotype-dependent.     

Developing explosive power: A comparison of technique and training

The influence of contraction type and movement type on power output of the upper body musculature was investigated across loads of 30-80% 1RM. Twenty seven males (21.9+/-3.1 years, 89.0+/-12.5 kg, 86.32+/-13.66 kg 1RM) of an athletic background but with no weight training experience in the previous six months volunteered for the study. The results were compared using multivariate analysis of variance with repeated measures (p< or =0.05). It was found that the combinations of load, movement and contraction type affected mean and peak power in different capacities. Mean power output for rebound motion was 11.7% greater than concentric only motion. The effect of the rebound was to produce greater peak accelerations (38.5%--mean across loads), greater initial force and peak forces (14.1%--mean across loads) and early termination of the concentric phase. Peak power output was most influenced by the ability to release the bar, the greater mean velocities across all loads (4.4% average velocity and 6.7% peak velocity) attained using such a technique appeared the dominating influence. Loads of 50-70% 1RM were found to maximize mean and peak power. Loading the neuromuscular system to maximize mean or peak power output necessitates an understanding of the force-velocity characteristics of the training movement and the requirements of the individual related to the athletic performance and their training status.     

Interval training for performance: a scientific and empirical practice. Special recommendations for middle- and long-distance running. Part I: aerobic interval training

This article traces the history of scientific and empirical interval training. Scientific research has shed some light on the choice of intensity, work duration and rest periods in so-called 'interval training'. Interval training involves repeated short to long bouts of rather high intensity exercise (equal or superior to maximal lactate steady-state velocity) interspersed with recovery periods (light exercise or rest). Interval training was first described by Reindell and Roskamm and was popularised in the 1950s by the Olympic champion, Emil Zatopek. Since then middle- and long- distance runners have used this technique to train at velocities close to their own specific competition velocity. In fact, trainers have used specific velocities from 800 to 5000m to calibrate interval training without taking into account physiological markers. However, outside of the competition season it seems better to refer to the velocities associated with particular physiological responses in the range from maximal lactate steady state to the absolute maximal velocity. The range of velocities used in a race must be taken into consideration, since even world records are not run at a constant pace.     

Specificity of arm training on aerobic power during swimming and running

The specificity of aerobic training for upper-body exercise requiring differing amounts of muscle mass was evaluated in 25 college-aged male recreational swimmers who were randomly assigned to either a non-training control group (N = 9), a 10-wk swim(S)-training group (N = 9), or a group that trained with a standard swim-bench pulley system (SB; N = 7). For all subjects prior to training, tethered-swimming peak VO2 averaged 19% below treadmill values (P less than 0.01), while SB-ergometry peak VO2 was 50% and 39% below running and swimming values, respectively (P less than 0.01). Significant (P less than 0.01) increases of peak VO2 in tethered swimming (11%) and SB (21%) were observed for the SB-trained group, while the S-trained group improved (P less than 0.01) 18% and 19% on the tethered swimming and SB tests, respectively. No changes were observed during treadmill running, and the control subjects remained unchanged on all measures. Comparisons between training groups indicated that although both groups improved to a similar extent when measured on the swim bench, the 0.53 l X min-1 improvement in tethered-swimming peak VO2 for the S-trained group was greater (P less than 0.05) than the 0.32 l X min-1 increase noted for the SB-trained group. The comparisons between SB and S exercise vs treadmill exercise support the specificity of aerobic improvement with training and suggest that local adaptations contribute significantly to improvements in peak VO2. Furthermore, the present data indicate that SB exercise activates a considerable portion of the musculature involved in swimming, and that aerobic improvements with SB training are directly transferred to swimming.     

A comparison of single-versus multi-modal exercise programs: effects on aerobic power

The purpose of this study was to compare the effects of a 10-week single mode (SM) training program (walk/jog) versus a multimode (MM) training program (walk/jog, cycle, arm crank) on peak aerobic power (VO2 peak) during three ergometry modes. Twenty Ss were stratified initially according to gender and then randomly assigned to either of the treatment groups. Seven additional Ss served as controls. Peak VO2 was determined during treadmill running, cycle ergometry and arm crank ergometry prior to and after ten weeks of training. Training for the SM group (N = 9) consisted of walk/jog three days per week for five weeks at approximately 50-60% peak VO2 and an energy cost of approximately 2400 kJ per week, then increased to approximately 3200 kJ for the duration of the study. Training for the MM group (N = 8) was isoenergetic to the SM group. However, the training differed in that subjects exercised one day walk/jog, one day cycling, and one day arm cranking. Controls were tested twice with no treatment between. Post-training VO2 peaks for the three ergometry modes were analyzed with an analysis of covariance, utilizing pre-training scores as a statistical covariate. The post-training SM VO2 was found to be significantly greater than either the MM or C when testing on the treadmill. No other comparison was statistically significant. These data support the concept that a conditioning program can become sufficiently variable so that expected increases in aerobic power are not produced, despite the fact that isoenergetic training is undertaken.(ABSTRACT TRUNCATED AT 250 WORDS)     

Cardiorespiratory fitness and aerobic performance adaptations to a 4-week sprint interval training in young healthy untrained females

Purpose

The aim of this study was to test the effects of sprint interval training (SIT) on cardiorespiratory fitness and aerobic performance measures in young females.

Methods

Eight healthy, untrained females (age 21 ± 1 years; height 165 ± 5 cm; body mass 63 ± 6 kg) completed cycling peak oxygen uptake (\( \dot{V}{\text{O}}_{2} \) peak), 10-km cycling time trial (TT) and critical power (CP) tests pre- and post-SIT. SIT protocol included 4 × 30-s “all-out” cycling efforts against 7 % body mass interspersed with 4 min of active recovery performed twice per week for 4 weeks (eight sessions in total).

Results

There was no significant difference in \( \dot{V}{\text{O}}_{2} \) peak following SIT compared to the control period (control period: 31.7 ± 3.0 ml kg^?1 min^?1; post-SIT: 30.9 ± 4.5 ml kg^?1 min^?1; p > 0.05), but SIT significantly improved time to exhaustion (TTE) (control period: 710 ± 101 s; post-SIT: 798 ± 127 s; p = 0.00), 10-km cycling TT (control period: 1055 ± 129 s; post-SIT: 997 ± 110 s; p = 0.004) and CP (control period: 1.8 ± 0.3 W kg^?1; post-SIT: 2.3 ± 0.6 W kg^?1; p = 0.01).

Conclusions

These results demonstrate that young untrained females are responsive to SIT as measured by TTE, 10-km cycling TT and CP tests. However, eight sessions of SIT over 4 weeks are not enough to provide sufficient training stimulus to increase \( \dot{V}{\text{O}}_{2} \) peak.

     

Comparison of short-term aerobic training and high aerobic power on tolerance to uncompensable heat stress.

This study investigated whether, in subjects of moderate aerobic fitness, short-term aerobic training could replicate the improved physiological responses to exercise-heat stress observed in individuals with a high level of aerobic fitness. Males of moderate (MF; <50 ml x kg(-1) min(-1) VO2peak, n = 8) and high (HF; >55 ml x kg(-1) x min(-1) VO2peak, n = 8) aerobic fitness walked at 3.5 km x h(-1) in the heat (40 degrees C, 30% relative humidity) wearing nuclear, biological, and chemical protective clothing. Tests were conducted once on HF subjects and on MF subjects before (MF-Pre) and after (MF-Post) a 2-week program 6 d x week(-1) of daily aerobic training (1 h treadmill exercise at 65% VO2peak for 12 d, 22 degrees C, 40% relative humidity). The training significantly increased VO2peak by 6.5%, while heart rate (fc) and rectal temperature (Tre) rise decreased during exercise in a thermoneutral environment. HF had lower body mass and body fat content than MF, and VO2peak remained lower in MF pre-or post-training. In the heat, MF-Post had a decreased skin temperature (Tsk) and an increased sweat rate compared with MF-Pre, but no changes were observed in fc, Tre, or tolerance time (TT). No significant differences during the first 60 min in Tre and fc were observed between the MF-Post and the HF subjects, though the HF subjects exhibited a lower Tsk. The endpoint Tre, deltaTre, and TT remained significantly higher in HF than in either the MF-Pre or MF-Post subjects. It was concluded that, in preparation for exercise in an uncompensable heat stress environment, short-term aerobic training offers little, if any, benefit and is not an adequate substitute for a high level of aerobic fitness resulting from habitual exercise and training.