Part 1 - Critique Analysis of the selection of tests used on a 1500 meters female athlete.  Maximal Oxygen Uptake (VO2 Max)

When an individuals resting metabolic rate is increased due to exercise the relevant muscles need adequate amounts of oxygen. Whilst the metabolic rate is at rest, the consumption of oxygen is minimal, indicating that the cardiorespiratory system is working at a sub maximal capacity. VO2 max is defined as the maximal rate at which an individual can take up and utilise oxygen whilst breathing air at sea level (Astrand 1986). In practical terms, it is a measure of cardiovascular function, which provides an indicator of the athletes endurance capabilities. When determining VO2 max in an incremental exercise test to volitional exhaustion, the following criteria should be considered in adults:

• A plateau in the oxygen uptake/exercise intensity relationship.
• A final respiratory exchange value of 1.15 L/min or above.
• A final heart rate of within 10 b.min-1 of the age related maximum.
• A post exercise (4 5 min) blood lacked a concentration of 8mmol.11 or more. (Eston and Reilly, 1996)

Protocol

Exhaustion should be the key element of the testing; this should be achieved within 9-15 minutes of continuous exercise. Guidelines for measuring VO2 max have been established according to running speeds and power output (British Association of Sport Science, 1988). Eston and Reilly, (1996) suggests that, one of the general recommendations for the assessment of VO2 max is that the subject should perform rhythmic exercise which requires a large muscle mass. A discontinuous protocol where exercise intensity should be increased at the end of each three-minute period. Extrapolation of expired air and heart rate should be collected during the final minute of each stage.

Validity

Vo2 max is a direct test and some would say has gold standard criterion, in the correct conditions, of cardiorespiratory fitness. Eston and Reilly (1996) consider it to be,

"& the single physiological variable which best defines the functional capacity of the cardiovascular and respiratory systems."

Normalisation of data should occur by taking the absolute value and then converting it to a value relevant to body weight. Therefore, Vo2 max ml. kg.-1 min.-1 should be considered.

Reliability

The reliability of the test is sound, with a correlation coefficient R-value of 0.85.

Specificity

Cardiovascular and respiratory functions are of fundamental importance to middle distance runners. As VO2 max is a direct indication of this. However, an important consideration for the external validity of the test, is that the subject is tested using a treadmill.

Preset of Blood Lactate Accumulation

Measuring blood lactate concentration during sub maximal exercise intensity can indicate anaerobic metabolism within the muscle. The term "onset of blood lactate accumulation" (OBLA) refers to systematic increasing in blood lactate equal to or greater than 4.0 mmols (Sjodin and Jacobs, 1981).

"Blood lactate levels provide a useful indication of energy derived from anaerobic glycolysis during exercise." (Bonifazi, 1993)

When an athlete is engaged in a test of progressively increasing intensity, a point is reached where effort can no longer be sustained by aerobic means. Thus anaerobic metabolism can be supervenes (Shephard, 1992).

Protocol

The protocol consists of 16 minutes continuous running on a treadmill during which running speeds is increased every four minutes. Lactate concentration is measured in blood samples obtained at the end of each four minutes stage for the subsequent determination of the running speed equipment to a reference concentration of 4mmol.l-1. Extrapolation of expired air, heart rate and blood sample should be collected during the final minute of each stage between 3-4, 7-8,11-12, and 15-16 minutes. However, is important note that this particular test had no blood sample between the 15-16 minutes stage.

Validity

In the obsession of obtaining data on the aerobic performance capabilities of an athlete, OBLA has a direct methodological approach. However, when analysing the absolute data it is extremely important to take into consideration the velocity of the onset of blood lactate accumulation (VOBLA). It also successfully predicts the subjects aerobic capacity by taking into account the level of exercise intensity achieved at the point of OBLA.

Reliability

The reliability of the test is sound, with a correlation coefficient R-value of 0.93.

Specificity

When dealing with middle distance runners, it is of fundamental importance that the coach or sport scientist understands the emphasis which must be placed upon the athletes anaerobic capacity.

"& measures of running economy can be made at the same time as the establishment of blood lactate responses. These are used for the determination of the exercise intensity corresponding to the OBLA." (Eston and Reilly, 1996)

Multigym Strength Evaluation

There is controversy regarding testing muscle strength. This is because the complexity of extrapolating data has been shown to vary considerably between studies. However, limited research has been carried out on the one repetition maximum using multigym equipment.

Protocol

The protocol must assess the ability of the athlete to be able to lift the maximum amount of weight over one repetition. To achieved this the subject has to go through a trial and error phase whilst weight is being added to achieve, in the subjects opinion, the one repetition maximum.

Validity

In this indirect test of strength many questions remain unanswered to the validity of the test. Thus, very poor validity is expected. This due to many different factors such as the quality of the technique and biomechanically factors such as limb length difference.

Reliability

The test and re-test ability is extremely questionable due to the trial and error method and the familliazation of the technique.

Specificity

The test used has some similar characteristics to that of running when looking at the close kinetic chain. However, due to the stable nature of equipment used the proprioception has been eliminated which is a key element of running. The following areas were assessed: shoulder press, lat pulldown, bicep curl, leg press, and bench press. The running technique is predominantly focusing on the leg action and to some degree the shoulder. Hence, the test should try to focus on these areas and disregard the bench press, lat pulldown, and bicep curl as they are not applicable to the middle distance runner.

Haemoglobin

Biochemical analyses of haemoglobin concentrations are usually used for medical evaluation. Whereby abnormally low measurements have been found to have a significant indication for the presence of anaemia. Erythrocytes are found to contain large amounts of haemoglobin. Marieb (1995) suggests that,

"Oxygen transport is the major function of erythrocytes. In the lungs, oxygen binds to iron atoms in haemoglobin molecules, producing oxyhaemoglobin. In body tissues, oxygen dissociates from iron, producing deoxyhaemoglobin." (Marieb, 1995)

Validity

As biochemical analysis is directly use by the medical profession to test haemoglobin the assumption is that is both valid and reliable. It is worth noting that increased levels of Iron deficiencies are associated with sweating and the luteal phase of the menstrual cycle. Therefore, is extremely important to know exactly when the sample was taken for analysis. Further, it must be known at what level of exercise intensity was the blood sample taken and exactly what stage of the menstrual cycle was the subject at?

Specificity

Endurance training has shown to have no significant effect on haemoglobin concentration in the blood. Anaemia can be detected in haemoglobin samples. The normal count for a female is 12 to 16 g per 100ml of blood.

Body Fat %

This indirect measurement of subcutaneous body fat using double skin fold was applied. The application of callipers which applies a constant pressure over a given range of skin thickness. Methods have varied in the skin fold sites with regression equations determined to predict the critical value.

Validity & Reliability

Trained testers have been shown to produce highly reliable skin fold measurements. With correlation coefficient R-values ranging from r =0.90 to r =0.97 (Wilmore, 1992). However, many authors have expressed concerns over the controversial site location. Pollock & Jackson (1984) suggested it is,

" &now recognised that the relationship between the sum of the skin folds and total body density is curvilinear, and not linear as was assumed in most original multiple regression equations".

Estimation of the percentage body fat for skin fold measurements have an error about 4%.

Specificity

It is important to determine the body fat percentage of endurance athletes. It is also understood that high levels of fat stores are associated with inactive subjects. Therefore, in elite endurance athletes the objective is to achieve low body weight percentage of fat.

"Endurance athletes attempt to minimise their fat stores, because excessive weight negatively affects performance."

(Wilmore, 1992)

Modifications of Testing Protocol of Muscle Strength and Body Fat %

Muscle Strength

Instead of multigym strength assessment the screening programme should adopt an isokinetic dynamometer to measure muscle strength. This would give the coach/sport scientist a direct insight of muscle imbalance and deficiencies. It would be far more beneficial to have an understanding of the hip, knee (extension and flexion), and ankle (plantar flexor and dorsiflexor) relevant muscle groups. From this a direct measure of peak torque normalised to body weight can be extrapolated.

Body Fats %

It would be beneficial to begin by abolishing the skin fold protocol altogether and use a relatively welcomed approach of hydrostatic weighing. This is a method of measuring body volume in which the athlete is weighed while submerged underwater. The difference between the scale weight on land and the underwater weight (corrected for water density) equals body volume. This value must be further corrected to account for any air in the body. The reliability of the test is sound, with a correlation coefficient R value of 0.94. It is an indirect method of calculating hold body volume which is also good indicator, of body fat. With none of the problems associated with location of measuring body fat.

Part 2 - Interpretation of Results

Onset of Blood Lactate Accumulation

Demographic data has been used to represent OBLA which in some situations can be constructed with the running speed equivalent of 2mmol.l-l and 4mmol.l-l. Because the direct absolute value of blood lactate concentration has been compared to it by indirect measures of exercise intensity using heart rate. It is has been recommended that presenting the data by joining the data points with straight line. The red dotted line indicates the anaerobic threshold. This is the point at which the aerobic energy system can no longer supply most of the demands of the body for adenosine triphosphate. At this point of 4mmol. of lactate concentration the heart rate was at 158bpm. The study also needs to address VOBLA. Due to lack of data provided Va max (maximal aerobic running velocity) cannot be attained which has been used by many other authors

(Fric et at, 1988; Bonifazi et al, 1993).

Maximal Oxygen Uptake (VO2 Max)

The absolute value of the VO2 max was at 3.5 L/min. Normalisation of the data to body weight is achieved by using the following formula:

3.5L/min. x1000ml

48.4ml.min-1 .kg-1

______________

=

72.3kg

Deason et al.,(1991) assessed 11 elite female middle distance runners. All test were performed on a level treadmill with the athletes producing a VO2 max of 61.6 ml.min-1 .kg-1. The VO2 max of the elite athletes is considerably higher than the subjects this should be the focusing point when determining the appropriate training method.

Multigym Strength Evaluation

Shoulder Press

Bicep Curl

Lat Pulldown

Leg

Bench Press

The above values were recorded for the subject. Limited research has been carried out on this indirect multigym assessment of strength. When comparing the subjects leg press values of 80 kgs the values look fairly normal for an untrained athlete. However, Staron et al. (1991) suggests that prior to a 20 week strength training programme to assess adaptations to strength. Female athletes were producing leg press values of 130 kgs and post 20 week training in the region of 280 kg.

Haemogobin

The subjects haemoglobin concentration was measured at 10.6 g.100ml.-1.

From these results we can conclude the levels are below expected norms. The standards vary between gender and age, but in women a value greater than 12.0 g. 100ml.-1 is expected. There is a condition known as sport's anaemia. When studying the epidemiology of sports anaemia it has been made fully clear that iron deficiencies are the primary factors. Marieb (1995) suggest that it can result from,

"& inadequate intake of iron containing foods and impaired iron absorption& the obvious treatment is iron supplements, but if chronic hemorrhage is the cause, blood transfusion may also be needed".

In this case as suggested the obvious treatment is iron supplementation. This is in order to be able to compete at a competitive level. The subject will also have to train harder aerobically.

Body Fat %

In order to calculate the body fat% from skin fold measurements the Durnin Womersley (1974) for site method was used, the results were as follows.

After feeding the result into the database a body fat measurement of 23.3% was indicated. Results in body fat is considered to be high. Wilmore (1988) suggest that, ideal body fat for a runner at this distance should be 15.5%. Yet again we can conclude in order for the subject to compete competitively she will have to train aerobically in order to achieve her goals.

Part 3 - Implementation to Training

Aerobic Training

As the aerobic demands are high for 1500 m, high intensity type training should take place. This will enable many physiologically unique adaptations to occur to the athlete. Enhancing the efficiency of the cardiovascular and cardiorespiratory systems to a level which is required to be competitive.

"This will increase both the number of capillary per muscle fibre and the number of capillaries recruit given cross-sectional area of muscle (Wilmore, 1994)".

With the female athlete indicating VO2 max levels of an untrained individual, it will be extremely advantageous to concentrate on aerobic training. This will also positively effect the body fat percentage. Carbohydrate intake should also be increased with a decrease in fat intake.

Interval training should consist of, 20 repetitions with a 15 seconds rest period of which 4 sets of 400 m should be applied. The intensity of which should be carried out at a constant level of around 80%. This percentage level can be determined by asking the athlete to perform her personal best.

Strength Training

As strength training is not highly required in middle distance runners. It would be far more advantageous to focus on muscle endurance. However, peak torque measurements are beneficial in determining muscle imbalances. The lower extremity needs to be considered with endurance training exercise. The subject should be advised to work at 60 to 65% of her maximum. This consist of five sets of which 15 repetitions should be carried out.

References

Astrand, P.O. and Rodahi, K. (1986) 3^rd ed. Textbook of Work Physiology. McGraw Hill, New York.

Bonifazi, M., Martelli, G., Marugo, L., Sardella, F. and Carli, G. (1993) Blood lactate accumulation in top level swimmers following competition. The journal of sports medicine and physical fitness. Vol. 33. Pp 13-18.

Deason, J. Powers, S.J., Lawler, J. Ayers, D. and Stuart, M. K. (1991). Physiological correlates to 800 meter running performance. The journal of sports medicine and physical fitness. Vol. 31. Pp 499-504.

Eston, R. and Reilly, T. (1996). Kinanthropometry and exercise physiology laboratory manual. Test producers and data. Published by, E & FN Spon.

Fric, J., Fric, Jr. J., Boldt, F., Stoboy, W., Meller, F. Feldt, and Drygas. (1988) Reproductive ill attained of post exercise lactate and anaerobic thresholds. International journal of sports medicine. Vol. 9. Pp. 310-312.

Hale, T., Armstrong, N., Hardman, A., Philip, J., Sharp, C. and Winter, E. (1992). British Association of Sports and Exercise Sciences, 2nd ed. Position Statement on the Physiological Assessment of the Elite Competitor. White Lane Press.

Maried, E.N. (1995). Human Anatomy and Physiology. 3^rd ed. Published by, Benjamin and Cunnings Publishing Company, Inc. Pp.592-610.

Shephard, R.J. (1992). Muscular Endurance and Blood Lactate. Cited in, Shephard, R.J. and Ĺstrand, P.O. Endurance in Sport. Published by, Blackwell Scientific Publications. Pp 215-255.

Sjodin, B. and Jacobs, I. (1981). Onset of blood lactate accumulation and marathon running performance. International journal of sports medicine. Vol. 2. Pp. 234-248.

Staron, R.S., Leonardi, M.J., Karapondo, D.L., Malickly, E.S., Falkael, J.E., Hagerman, F.C. and Hikidia, R.S. (1991). Strength skeletal muscle adaptations in heavy resistance trained women after detraining and retraining. Journal of Applied Physiology. Vol. 70. Pp 631-640.

Öberg, B., Bergman, T. and Tropp, H. (1987). Testing of isokinetic muscle strength in the ankle. Medical Science of Sport. Vol. 19. Pp 318-323.

Pollock, M.L and Jackson, A.S. (1984). Research progress in validation of clinical methods of assessing body composition. Medical Science of Sport. Vol. 16. Pp 606-613.

Wilmore, J.H. and Costill, D.L. (1994). Physiology of Sport and Exercise. Published by, Human Kinetics.