Professor Anthony J Sargeant directed the Amsterdam Research Group who carried out this research.

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This research was part of the PhD thesis of JG Beltman carried out in the department established and directed by Professor Tony Sargeant. It applied techniques for the analysis of high energy phophates in human muscle fibre fragments developed by Arnold de Haan with techniques established by another of Professor Sargeant’s PhD students, Jose Sant’Ana Perreira (sadly deceased) for the characterization of human muscle fibre fragments dissected from needle biopsies.
Acta Physiologica Scandanavica. 2004 Feb;180(2):187-93

AIM: This methodological study investigated the number of brief maximal voluntary isometric contractions (MVC) needed to show evidence of fibre activation, as indicated by changes in the phosphocreatine to creatine (PCr/Cr) ratio.

METHODS: Subjects performed series of four, seven and/or 10 MVC (1 s on, 1 s off) of the m. quadriceps (60 degrees -flexion angle).

Biopsy samples of the m. vastus lateralis were taken at rest and immediately post-exercise. Single muscle fibres were dissected from the freeze-dried samples and classified as types I, IIA or IIAX, using mATPase stainings. Fragments of characterized fibres were analysed for PCr and Cr content. Analyses of variance were performed to investigate changes in PCr/Cr per fibre group over time, followed by Bonferroni post-hoc test  (P<0.01). The fifth percentile of resting values of each fibre group was determined.

RESULTS: Mean PCr/Cr ratio after four, seven and 10 MVCs were significantly lower for all fibre groups (P < 0.01). The mean decreases were 44, 64 and 76%, respectively. However, only after seven and 10 contractions PCr/Cr ratios of all, but three type I and two type IIAX fibres, individual fibres were below the fifth percentile.

CONCLUSION: In very short duration exercise, involving seven brief maximal voluntary contractions, changes in the PCr/Cr ratio indicated activation of different characterized muscle fibre fragments. The results suggest that this approach may be useful for investigating the pattern of fibre type activation in exercise of very short duration

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Research directed by Professor Anthony J Sargeant into stair descent in the elderly

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Many elderly people have falls while descending stairs. Such falls often result in serious injury and can lead to premature death. This research set out to look at the extent to which knee and ankle movement was different between young and elderly subjects. The results suggests that exercise to maintain a large range of joint motion may be important in the prevention of falls in the elderly.
European Journal of Applied Physiology. 2004 Mar;91(2-3):287-95

A major factor limiting mobility in elderly subjects is their difficulty with descending steps but the physiological and biomechanical basis of this problem is not well understood. To address this question we have compared the kinematics of stepping down in six elderly male subjects and six weight- and height-matched younger subjects. Five reflective markers were positioned on the lower limbs and subjects were filmed stepping down from four heights (200, 250, 300, and 335 mm).

Maximum angular displacements for the knee and ankle of the supporting limb were expressed as a percentage of each subject’s passive range of motion (ROM). Time spent in ‘foot flat’ during single support was also compared. The results show the elderly subjects sustained dorsiflexion and a ‘foot flat’ position of the support limb for a significantly (P<0.05) longer period than the young (approximately 20%). Consequently, elderly subjects utilised a greater percentage of their passive ankle ROM compared to the young (elderly approximately 200%; young approximately 125%). We conclude that the elderly maintained a ‘foot flat’ position for a longer period possibly to increase the time spent on a larger base of support. These results suggest that exercise prescription in the elderly should include stretching in order to increase the ROM at the ankle joint

Human exercise performance of military personnel

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Research conducted by Professor Anthony J Sargeant as part of his PhD thesis at the Joint Services Medical Rehabilitation Unit of the British Armed Forces. He applied the one-leg vs two-leg model that he developed and introduced as a way of exploring central and peripheral limits to exercise performance to young male service personnel undergoing residential rehabilitation following fracture of the leg.

Scandanavian Journal of Rehabilitation Medicine
Scand J Rehabil Med. 1975;7(2):45-50

Twenty-five patients with healed fractures of the lower limb and nine normal control subjects were measured anthropometrically and during maximal and submaximal one- and two-leg bicycle exercise. Oxygen intake at a given submaximal work level of 450 kmp min-1 and cardiac frequency at an oxygen intake of 1.5 I min-1 were significantly higher (p less than 0.001) in the injured compared with the uninjured limbs of the patients and normal subjects. The maximum aerobic power of the injured and uninjured limbs of the patients and normal subjects. The maximum aerobic power of the injured and uninjured limbs of the patients were 18.8% (0.44 I min-1) and 25.6% (0.61 I min-1) respectively lower than the right and left legs of the control subjects. The corresponding value for 2-leg work was 17.6% (0.51 I min-1). The deterioration in 1-leg performance of the patients was associated with a concomitant decrease in leg muscle (plus bone) volume. In 2-leg work this factor was also probably combined with a deterioration in performance due to general cardiovascular deconditioning

Research by Professor Anthony J Sargeant into estimating human fat, muscle and bone volumes.

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This preliminary report to the Physiological Society describes research which formed part of the PhD of Tony Sargeant. It was carried out before the days of CT or MRI scanning and involves many hours of meticulous measurements from conventional X-rays and anthropometry.
Journal of Physiology. 1975 Jan;244(1):13P-14P

A research report of methodologies for the assessment of limb tissues (fat, muscle, bone).

Research into recruitment of different human muscle fibre types by the research group directed by Anthony J Sargeant

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This research was part of a long term interest of Professor Anthony J Sargeant in the extent to which different muscle fibre types are recruited to meet the demand for mechanical output in human exercise. The research was carried out under his direction by members of his research group in Amsterdam where JG Beltman was his PhD student.
European Journal of Applied Physiology. 2004 Aug;92(4-5):485-92

This study investigated the recruitment of type I, IIA and IIAX fibres after seven isometric contractions at 40, 70 and 100% maximal voluntary knee extension torque (MVC, 1 s on/1 s off). Biopsies of the vastus lateralis muscle were collected from seven subjects at rest and immediately post-exercise. Fibre fragments were dissected from the freeze-dried samples and characterized as type I, IIA and IIAX using mATPase staining.

Phosphocreatine (PCr) and creatine (Cr) content were measured in the remaining part of characterized fibres. A decline in the ratio of PCr to Cr (PCr/Cr) was used as an indication of activation. The mean peak torques were, respectively, 39 (2), 72 (2) and 87 (6)% MVC. Cumulative distributions of type I and IIA fibres were significantly shifted to lower PCr/Cr ratios at all intensities (Kolmogorov-Smirnov test, P<0.05). The cumulative distribution of type IIAX fibres showed a significant leftward shift only at 87% MVC ( P<0.05). A hierarchical order of fibre activation with increasing intensity of exercise was found, with some indication of rate coding for type I and IIA fibres. Evidence for activation of type IIAX fibres was only found at 87% MVC.

Research into central and peripheral determinants of Maximum Oxygen Uptake

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This research proposed and carried out by Professor Anthony J Sargeant examined the central and peripheral limitations and and changes in maximum oxygen uptake when different muscle mass was involved.
Journal of Physiology. 1975 Jan;244(1):50P

The first preliminary publication of research initiated by Anthony J Sargeant as part of his PhD thesis

This research which formed part of the PhD thesis of Professor Anthony J Sargeant was given at a Physiological Society Meeting

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Preliminary report of one part of the research that formed the PHd thesis of Anthony J Sargeant