Effects of Pollen Extract Upon Adolescent Swimmers
Key words: Performance, Swimming, Pollen, Diet.
The sporting situation is an intensely competitive one in which athletes will search for any improvement in performance, however small it may be. Accordingly, a wide range of ergogenic aids in the form in this field. One of the more recent innovations in the use of a pollen extract which has been claimed to produce improvements in athletic performance. This product has been marketed as T-60, containing pollen extract as well as vitamins B, C, and E. The two main beneficial effects of this product have been claimed to be an increased resistance of respiratory tract infection (Lindal, 1978; Mark-Vendel, 1978) and an effect on protein synthesis (Dubrisay, 1972). A large number of the studies carried out in this area have been rather poorly controlled, and it was the aim of the present study to determine whether or not administration of a pollen extract could influence performance.
Twenty young competitive swimmers were used as subjects, comprising 16 males and 4 females. Mean age of the subjects was 15.7 years (range 11.5 to 20 years). All subjects were training on a daily basis, and all had been training for some months prior to the beginning of the test period. Subjects were divided into two groups, each containing 8 males and 2 females, the selection being random otherwise. A series of test as detailed below was then performed on each subject. These tests were repeated after a six-week period during which subject ingested either T-60 or placebo (cod-liver oil Capsules). Treatment administration was performed on a double blind basis in order to minimize any subjective bias. Differences between groups were assessed by the student's t-test, and differences within each group as a result of treatment were assessed by a paired t-test.
Height and weight were recorded, in addition to percentage body fat according to the method of Durin and Rahaman (1967). Right and left-hand grip strength measurements were made using a grip dynamometer (Takentiki Vogyo, Japan). Quadriceps isometric strength (MVC) and endurance time at 50% of MVC were measured using an isometric chair constructed after the manner of Thorstensson (1976).
Maximum oxygen uptake (VO2 max) was assessed by using stepwise increases in workload on friction braked Monark bicycle ergometer. The attainment of VO2 max was established according to the leveling off criterion of Astrad and Salrin (1961). Respiratory variables were assessed on a P.K. Morgan automatic gas analysis system comprising a Fleisch pneumotachograph, paramagnetic O2 analyzer and infra-red CO2 analyzer.
Vital capacity (VC) and forced expiratory volume (FEV1) was obtained using a Vitalograph spirometer.
Haemoglobin (Hb) concentration was estimated by conversion to cyanmethaemoglbin using Drakin's regent (BDH); haematocrit was obtained using a Hawksley micro-haematocrit system.
Results are presented in summary in Table 1.
Comparison of T-60 and placebo groups. Values are means ± Sem. The right hand column shows the differences between the changes observed in the two groups. A full explanation of the tests employed is given in the text.
Body weight and height increased in both groups during the test periods (p. <0.01). There were no differences between groups either before or after the test period. There were no differences in body fat content between the groups, and no change took place in either group.
Strength and Endurance Test
No significant changes took places in right hand-grip strength, isometric leg strength and isometric endurance time, with no difference between the groups. However left hand-grip strength showed significant improvement in both groups (p < 0.05 in both groups). No differences, however, were found to exist between the groups.
A significant decrease (p< 0.05) in blood hemoglobin concentrations took place during the trial period with mean (±SD) reductions of 1.05 ± 0.91 and 0.61 ± 0.67 g/100mls for placebo group and T-60 group respectively.
The haematocrit (percentage) was found to decrease in the T-60 group significantly (p < 0.05); however there were no differences between the two groups.
The VO2 max, expressed in 1/min, showed a significant improvement in both the T-60 and placebo group (p< .051); with mean (± SD) increase of 0.27 ± 0.09 and 0.24 ± 0.09 1/min respectively. If allowance is made for the increase in body weight, which occurred during the test period, this increase in VO2 max, expressed in ml/kg/min does not assume statistical significance.
Vital capacity increased considerably in the group taking T-60 (p < 0.05); a small increase was also observed in the control group, but this did not attain statistical significance. No significant difference was found between the groups.
Forced expiratory volume in 1 second was not found to change in either group nor was any significant difference found between the groups.
The subjects used for the present study were healthy adolescents differing from the normal population only in that they were all engaged on a strenuous program of physical training. They may thus be considered to represent the group at which the beneficial effects of pollen supplementation are aimed.
If the body weight and height of these subjects are compared with non-athletic children of comparable age, almost all were heavier and taller than average (Bayer and Bayler, 1976); this is in agreement with results obtained by Eriksson et al (1977) for a comparable population of swimmers. The results did not indicate that administration of T-60 had any effect on body weight, height or body fat content. It would not, however, be expected that any such effects would become apparent within the time scale of this experiment.
The normal training program undertaken by the subjects included two weight-training sessions weekly, with the aim of increasing muscular strength. In spite of this, there were no significant increases in either group recorded for right hand grip strength or for quadriceps strength. In contrast to this finding the left-hand grip strength showed comparable increases in both groups. This may be explained by the fact that the left-hand strength is generally weaker than the right; any bilateral training carried out would thus represent a greater stimulus to the left side and consequently produce a greater improvement in performance.
The significance of the changes in vital capacity is not immediately clear. The results show an increase in VC in the T-60 group but not in the placebo group. This change, however, is not sufficiently large to cause a significant difference to exist between the two groups. The values obtained for all subjects in the present study are higher than those of normal adolescents (Engstrom et al, 1962). This finding is in agreement with other results obtained from swimmers (Andrews et al, 1972; Eriksson et al, 1977) and is also in agreement with the suggestion that a large VC is required for success in competitive swimming (Astrand et al, 1963).
A high correlation has also been shown to exist between VO2 max recorded during work on a bicycle erometer and swimming performance (Astrand et al, 1964). Although both groups recorded a higher value for VO2 max following the test period there was no difference between the two groups, and the difference can therefore be ascribed to the effects of the training regimen.
The VO2 max, when related to body weight, did not increase significantly; it seems probable, however, that the absolute aerobic power is of greater relevance to swimmers as the body weight is reduced to a large extent by submersion.
The changes in hematological variables (Hb and Hct) which were recorded would appear to be a little consequences, and probably reflect the haemadilution which normally accompanies a period of physical training.
The results would appear to indicate that there is no beneficial effect to be obtained by administration of pollen extract to swimmers. Before this conclusion can be stated with any certainty however, two points must be borne in mind. The first of these is that the present test lasted only six weeks; by comparison with the time scale which most training programs are conducted, this is an extremely short space of time and may not be of sufficient duration to produce a measurable effect. Secondly, it was noted that the placebo group, during the six week experimental period, missed a total of 27 day's training through illness while T-60 group missed 4 days in total. All days missed in both groups were the result of upper respiratory tract infections. Because of the small numbers involved, these data are not readily amenable to statistical evaluation. They do, however, suggest that the swimmers taking T-60 might expect to miss only 1 day in 105 due to upper respiratory tract infection; this compares extremely favorably with the placebo group who might expect to miss 1 day in 16. Such a difference expected to have important consequences for the athlete whose performance is dependent on the ability to engage in consistent physical training.
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