SRM Training System Research Articles

Morphological characteristics and power output in professional road cyclists during the competition phase

Abstract Study aim: The purpose of this study was to investigate changes in the power output and major morphological characteristics during the competition phase. We hypothesised that substantial overloads occurring during this stage cause a decrease in body mass, fat and power output levels in the cyclists. Material and methods: Nine members from an affiliated Professional Cycling Group ActiveJet Team were observed during the period between January and September. Their mean age was calculated as 25.1 ± 1.6 years. Each month the main somatic fea­tures were determined and the BMI and Rohrer index were measured. The level of adipose tissue was checked using the Tanita BC-418 Ma and the Schoeberer Rad Messtechnik SRM training system was employed to record the maximum level of power output. The following tests were used to collect data: Shapiro-Wilk and ANOVA (assessment of the distribution of variables), Duncan (assessment of the changes of variables), and Pearson correlation coefficient (assessment of power dependence and morphological features). A significance coefficient of α = 0.05 was assumed. Results: The research of the studied group revealed a steady decrease in the body mass and fat percentage but no significant differences in power output levels. Its peak was reached in the middle of the starting phase (1195.3 ± 222.3 W) and the lowest level was noted during the last month of our observation (1114.1 ± 152.1 W; D = 81.2 W, p = 0.088). Correlations were found between body mass, fat composition and power output levels: moderate for mass (r = 0.383-0.778) and fat (r = 0.352-0.629) content to power output and small negative for height to power output. In most cases, however, they were either weak or low (r = -0.017-0.339). Conclusions: Significant changes in the morphological characteristics (body weight 70.2 ± 6.4-69.2 ± 5.9 kg, p < 0.001; BMI 21.4 ± 1.9-21.1 ± 1.7, p < 0.001; Rohrer index 1.18 ± 0.11-1.16 ± 0.10, p < 0.001; fat 9.2 ± 3.2-8.2 ± 2.3, p < 0.001) and no differences in power output combined (1151.0 ± 272.4-1114.1 ± 152.1 W, p = 0.434) with medium correlations of these determinants (body height - 2.53-0.354; body weight 0.383-0.778; fat 0.352-0.629) indicate the significance of motor charac­teristics in road racing cyclists. Thus levels in its competency and performance outcomes are determined to a greater extent by factors other than the somatic characteristics.

Mathematical model of track cycling: the individual pursuit

Mathematical modelling has been used to predict the performance of cyclists for a number of years. The aim of this study was to develop a mathematical model for Individual Pursuit (IP) cyclists on an indoor velodrome, taking into account the effects of leaning in the bends and the actual position of the rider on the track using data collected by the SRM training system. This model uses forward integration to predict the velocity of the centre of mass and the finishing time for IP athletes, accurate to within 3% with currently available input data.

Electrically Assisted Cycling

The purpose of this study was to assess the potential of the electrically assisted bicycle (EAB) as a novel tool for meeting the physical activity guidelines in terms of intensity. Twelve habitually active adult subjects were requested to cycle a track of 4.3 km at an intensity they would normally choose for commuter cycling, using three different support settings: no support (NO), eco support (ECO), and power support (POW). For estimating the intensity, the oxygen consumption was measured by using a portable gas-analyzing system, and HR was simultaneously measured. The bicycle was equipped with the SRM Training System to measure subjects' power output, pedaling rate, and the cycle velocity. Mean intensity was 6.1 MET for NO, 5.7 MET for ECO, and 5.2 MET for POW. Intensity was significantly lower in POW compared with that in NO. No differences were found between NO and ECO and between ECO and POW. Mean HR was significantly higher in NO compared with that in ECO and POW. The cycling speed with electrical support settings was significantly higher than cycling in the NO condition. Mean power output during cycling was significantly different among all three conditions. Most power outputs were supplied in the NO condition, and the lowest power output was supplied in the POW condition. Intensity during cycling on an EAB, in all three measured conditions, is sufficiently high to contribute to the physical activity guidelines for moderate-intensity health-enhancing physical activity for adults (cutoff, 3 MET). Further study is needed to conclude whether these results still hold when using the EAB in regular daily life and in subjects with other fitness level.

Assessment Influence on Peak Power Output and Road Cycling Performance Prediction

The influence of cycling assessment on peak power output and road-based cycling performance prediction was evaluated in twelve well-trained amateur cyclists (mean ± SD; age, 35 ± 8 yr; body mass, 74.1 ± 6.7 kg; stature: 181 ± 6 cm). Determining peak power output, cyclists completed a graded i) ramp assessment on a Kingcycle air-braked ergometer (PPOKING), ii) continuous assessment on a SRM electromagnetically-braked ergometer (PPOSRM), and iii) discontinuous assessment on a Monark friction-braked ergometer (PPOMON). Furthermore, a 40-km road-based individual cycle race was completed. Throughout each, power was measured using an SRM Training System. Despite no differences (p > 0.05) in V̇DO2peak across graded assessments, PPOKING (387 ± 49W) was 3.6% higher (p < 0.05) than PPOSRM (373 ± 38W) and 9% higher (p < 0.05) than PPOMON (352 ± 41W). Relating assessment-derived peak power output with road-based performance (mean power: 288 ± 36W; mean time 62:00 ± 3:13 min:sec), PPOKING (r = 0.94: p < 0.001), PPOSRM (r = 0.87; p< 0.001) and PPOMON (r = 0.90; p < 0.001) were strongly correlated to mean power, but not time (PPOKING; r = −0.41; p > 0.05: PPOSRM; r = −0.42; p > 0.05: PPOMON; r = −0.41: p > 0.05). Independent of determination, peak power output was strongly related to performance power and may provide effective means of obtained training and racing intensities.

Electrical Assisted Cycling: Energy Expenditure, Heart Rate and Power Output

PURPOSE: To assess the potential of an electric bicycle as a novel device for meeting the physical activity guidelines, in terms of energy expenditure (EE). Does the self selected physiological load of electric assisted cycling meet the recommended intensity standards for health enhancing physical activity (4 MET for moderate intensity and 55% of the maximum heart rate for vigorous intensity)? METHODS: 12 habitually active subjects (age 32-60 years; 6M, 6F) were requested to cycle a track of 4.3 km at an intensity they would normally choose for cycling to work, under three different conditions: no support, eco support and power support. EE (K4b2 Cosmed, Italy) was estimated and heart rate (Polar S810i Electro, Finland) was measured. The bicycle was equipped with the SRM Training System (Schoberer Rad Messtechnik, Germany) to measure power output, pedalling rate and cycle velocity. RESULTS: For unsupported cycling (UN) EE was 6.1 ± 1.6 Metabolic Equivalent (MET), for cycling with Eco support (ECO) EE was 5.7 ± 1.2 and for cycling with Power support (POWER) EE was 5.2 ± 1.4. EE was significantly lower with POWER compared to UN. No differences were found between UN and ECO and ECO and POWER. Mean heart rate was 124 ± 23 (74 ± 14% of the estimated maximum heart rate (HRmax)), 116 ± 22 (69 ± 13% HRmax) and 112 ± 23 beats per minute (67% ± 14% HRmax) for UN, ECO and POWER respectively. Mean heart rate was significantly higher for UN compared to ECO and POWER. No differences were found between ECO and POWER. Mean power output was 118 ± 31, 102 ± 25 and 94 ± 29 Watt for UN, ECO and POWER respectively and was significantly different between all three conditions. Mean pedaling rate was 55 ± 6, 52 ± 6 and 49 ± 7 (rpm) for UN, ECO and POWER respectively. Mean pedaling rate was significantly higher for UN compared to ECO and POWER. No differences were found between the two conditions with support. Mean cycling speed was 19.6 ± 2.4, 21.1 ± 2.2 and 23.4 ± 1.7 km/h for UN, ECO and POWER respectively and differed significantly between the three conditions. CONCLUSIONS: EE during electrical assisted cycling, in all three measured conditions, is sufficiently high to meet both moderate and vigorous intensity standards of the physical activity guidelines for adults. A higher speed was achieved while cycling with support, but less power was produced compared to unsupported cycling.

Comparison of different theoretical models estimating peak power output and maximal oxygen uptake in trained and elite triathletes and endurance cyclists in the velodrome

The aim of this study was to assess which of the equations that estimate peak power output and maximal oxygen uptake ([Vdot]O2max) in the velodrome adapt best to the measurements made by reference systems. Thirty-four endurance cyclists and triathletes performed one incremental test in the laboratory and two tests in the velodrome. Maximal oxygen uptake and peak power output were measured with an indirect calorimetry system in the laboratory and with the SRM training system in the velodrome. The peak power output and [Vdot]O2max of the field test were estimated by means of different equations. The agreement between the estimated and the reference values was assessed with the Bland-Altman method. The equation of Olds et al. (1995) showed the best agreement with respect to the peak power output reference values, and that of McCole et al. (1990) was the only equation to show good agreement with respect to the [Vdot]O2max reference values. The [Vdot]O2max values showed a higher coefficient of determination with respect to maximal aerobic speed when they were expressed in relative terms. In conclusion, the equations of Olds et al. (1995) and McCole et al. (1990) were best at estimating peak power output and [Vdot]O2max in the velodrome, respectively.

Power Output during the Tour de France

The aim of this study was to evaluate the demands of riding a "Grand Tour" by monitoring both heart rate and power output in 15 professional cyclists. SRM power output profiles (SRM Trainingsystem, Jülich, Germany) were collected during 148 mass start stages during the 2005 Tour de France and analyzed to establish average power, heart rate (HR) and cadence produced in different terrain categories (flat [FLT]; semi-mountainous [SMT]; mountainous [MT]). The maximal mean power (MMP) for progressively longer durations was quantified. Average HR was similar between FLT (133 +/- 10 bpm) and SMT (134 +/- 8 bpm) but higher during MT (140 +/- 3 bpm). Average power output revealed a similar trend (FLT 218 +/- 21 W [3.1 +/- 0.3 W/kg], SMT 228 +/- 22 W [3.3 +/- 0.3 W/kg], and MT 234 +/- 13 W [3.3 +/- 0.2 W/kg]). Cadence during MT was approximately 6 - 7 rpm lower (81 +/- 15 rpm) compared to FLT or SMT. During MT stages, the MMP for 1800 sec. was highest (394 W vs. 342 W) but the MMP 15 was lower (836 W vs. 895 W) compared to FLT. The data document comprehensively the power output demands during the Tour de France.

Laboratory versus Outdoor Cycling Conditions: Differences in Pedaling Biomechanics

The aim of our study was to compare crank torque profile and perceived exertion between the Monark ergometer (818 E) and two outdoor cycling conditions: level ground and uphill road cycling. Seven male cyclists performed seven tests in seated position at different pedaling cadences: (a) in the laboratory at 60, 80, and 100 rpm; (b) on level terrain at 80 and 100 rpm; and (c) on uphill terrain (9.25% grade) at 60 and 80 rpm. The cyclists exercised for 1 min at their maximal aerobic power. The Monark ergometer and the bicycle were equipped with the SRM Training System (Schoberer, Germany) for the measurement of power output (W), torque (Nxm), pedaling cadence (rpm), and cycling velocity (kmxh-1). The most important findings of this study indicate that at maximal aerobic power the crank torque profiles in the Monark ergometer (818 E) were significantly different (especially on dead points of the crank cycle) and generate a higher perceived exertion compared with road cycling conditions.

Comparison of nine theoretical models for estimating the mechanical power output in cycling

Objective: To assess which of the equations used to estimate mechanical power output for a wide aerobic range of exercise intensities gives the closest value to that measured with the...

Energy Intake and Energy Expenditure of Elite Cyclists During Preseason Training

In the last years, the interest in sport nutrition has increased. The purpose of this study was to quantify the nutritional status of eleven cyclists of a professional team (age: 28.7+/-4.2 yr; height: 181.0+/-4.2 cm; weight: 71.0+/-5.2 kg; body fat: 10.2+/-2.4%), during basic pre-season training. The athletes trained on five days (160 km per day) and respected one rest-day (33 km). The food of the cyclists, which was chosen by the riders themselves, was weighed and recorded for six days, the protocols were analysed through the PRODI 4.3 EXPERT database. The daily energy intake which averaged 13.5 MJ (59% carbohydrates, 19% proteins, and 21% fat), was compared to the mean daily consumption of energy (19.1 MJ), which was calculated from the basal metabolic rate and the energy turnover while training (directly measured through the SRM Training system). The daily energy expenditure was 30% higher than the daily energy intake. The analysis of the food diary showed that these experienced riders composed a carbohydrate-rich and low-fat diet by themselves as recommended for high-performance endurance athletes. When compared to nutritional guidelines, the composition of the diet in the present study can be considered as adequate.

Effects on the crank torque profile when changing pedalling cadence in level ground and uphill road cycling

Despite the importance of uphill cycling performance during cycling competitions, there is very little research investigating uphill cycling, particularly concerning field studies. The lack of research is partly due to the difficulties in obtaining data in the field. The aim of this study was to analyse the crank torque in road cycling on level and uphill using different pedalling cadences in the seated position. Seven male cyclists performed four tests in the seated position (1) on level ground at 80 and 100rpm, and (2) on uphill road cycling (9.25% grade) at 60 and 80rpm.The cyclists exercised for 1min at their maximal aerobic power. The bicycle was equipped with the SRM Training System (Schoberer, Germany) for the measurement of power output (W), torque (Nm), pedalling cadence (rpm), and cycling velocity (kmh−1). The most important finding of this study indicated that at maximal aerobic power the crank torque profile (relationship between torque and crank angle) varied substantially according to the pedalling cadence and with a minor effect according to the terrain. At the same power output and pedalling cadence (80rpm) the torque at a 45°crank angle tended (p<0.06) to be higher (+26%) during uphill cycling compared to level cycling. During uphill cycling at 60rpm the peak torque was increased by 42% compared with level ground cycling at 100rpm.When the pedalling cadence was modified, most of the variations in the crank torque profile were localised in the power output sector (45° to 135°).