Pierre-Marie Leprêtre

Health benefits of physical activity in older patients: a review

As the number of elderly persons in our country increases, more attention is being given to geriatric healthcare needs and successful ageing is becoming an important topic in medical literature. Concept of successful ageing is in first line on a preventive approach of care for older people. Promotion of regular physical activity is one of the main non‐pharmaceutical measures proposed to older subjects as low rate of physical activity is frequently noticed in this age group. Moderate but regular physical activity is associated with a reduction in total mortality among older people, a positive effect on primary prevention of coronary heart disease and a significant benefit on the lipid profile. Improving body composition with a reduction in fat mass, reducing blood pressure and prevention of stroke, as well as type 2 diabetes, are also well established. Prevention of some cancers (especially that of breast and colon), increasing bone density and prevention of falls are also reported. Moreover, some longitudinal studies suggest that physical activity is linked to a reduced risk of developing dementia and Alzheimer’s disease in particular.

Impact of short‐term aerobic interval training on maximal exercise in sedentary aged subjects

Background:  Ageing is known to be associated with a decrease in peak oxygen consumption (VO2peak) and maximal tolerated power (MTP). Regular physical exercise is the most appropriate to improve aerobic capacity, but its effect still remained discussed in old people.

Effect of a short-term intermittent exercise-training programme on the pulse wave velocity and arterial pressure: a prospective study among 71 healthy older subjects.

Aims of the study:  Stiffening of large arteries has been associated with increased cardiovascular outcomes among older subjects. Endurance exercises might attenuate artery stiffness, but little is known about the effects of intermittent training programme. We evaluate the effect of a short Intermittent Work Exercise Training Program (IWEP) on arterial stiffness estimated by the measure of the pulse wave velocity (PWV).

Effects of sports drinks on the maintenance of physical performance during 3 tennis matches: a randomized controlled study

BackgroundTennis tournaments often involve playing several consecutive matches interspersed with short periods of recovery.ObjectiveThe objective of this study was firstly to assess the impact of several successive tennis matches on the physical performance of competitive players and secondly to evaluate the potential of sports drinks to minimize the fatigue induced by repeated matches.MethodsThis was a crossover, randomized controlled study. Eight male regionally-ranked tennis players participated in this study. Players underwent a series of physical tests to assess their strength, speed, power and endurance following the completion of three tennis matches each of two hours duration played over three consecutive half-days (1.5éday period for each condition). In the first condition the players consumed a sports drink before, during and after each match; in the second, they drank an identical volume of placebo water. The results obtained were compared with the third `resté condition in which the subjects did not play any tennis. Main outcomes measured were maximal isometric strength and fatigability of knee and elbow extensors, 20-m sprint speed, jumping height, specific repeated sprint ability test and hand grip strength.ResultsThe physical test results for the lower limbs showed no significant differences between the three conditions. Conversely, on the upper limbs the EMG data showed greater fatigue of the triceps brachii in the placebo condition compared to the rest condition, while the ingestion of sports drinks attenuated this fatigue.ConclusionsThis study has demonstrated for the first time that, when tennis players are adequately hydrated and ingest balanced meals between matches, then no large drop in physical performance is observed even during consecutive competitive matches.Trial registrationClinicalTrials.gov: NCT01353872.

Comparison Between 30-15 Intermittent Fitness Test and Multistage Field Test on Physiological Responses in Wheelchair Basketball Players

The intermittent nature of wheelchair court sports suggests using a similar protocol to assess repeated shuttles and recovery abilities. This study aimed to compare performances, physiological responses and perceived rating exertion obtained from the continuous multistage field test (MFT) and the 30-15 intermittent field test (30-15IFT). Eighteen trained wheelchair basketball players (WBP) (WBP: 32.0 ± 5.7 y, IWBF classification: 2.9 ± 1.1 points) performed both incremental field tests in randomized order. Time to exhaustion, maximal rolling velocity (MRV), VO2peak and the peak values of minute ventilation (VEpeak), respiratory frequency (RF) and heart rate (HRpeak) were measured throughout both tests; peak and net blood lactate (Δ[Lact−] = peak–rest values) and perceived rating exertion (RPE) values at the end of each exercise. No significant difference in VO2peak, VEpeak, and RF was found between both tests. 30-15IFT was shorter (12.4 ± 2.4 vs. 14.9 ± 5.1 min, P < 0.05) but induced higher values of MRV and Δ[Lact−] compared to MFT (14.2 ± 1.8 vs. 11.1 ± 1.9 km·h−1 and 8.3 ± 4.2 vs. 6.9 ± 3.3 mmol·L−1, P < 0.05). However, HRpeak and RPE values were higher during MFT than 30-15IFT(172.8 ± 14.0 vs. 166.8 ± 13.8 bpm and 15.3 ± 3.8 vs.13.8 ± 3.5, respectively, P < 0.05). The intermittent shuttles intercepted with rest period occurred during the 30-15IFT could explain a greater anaerobic solicitation. The higher HR and overall RPE values measured at the end of MFT could be explained by its longer duration and a continuous load stress compared to 30-15IFT. In conclusion, 30-15IFT has some advantages over MFT for assess in addition physical fitness and technical performance in WBP.

Effects of Modified Multistage Field Test on Performance and Physiological Responses in Wheelchair Basketball Players

A bioenergetical analysis of manoeuvrability and agility performance for wheelchair players is inexistent. It was aimed at comparing the physiological responses and performance obtained from the octagon multistage field test (MFT) and the modified condition in “8 form” (MFT-8). Sixteen trained wheelchair basketball players performed both tests in randomized condition. The levels performed (end-test score), peak values of oxygen uptake (VO2peak), minute ventilation (VEpeak), heart rate (HRpeak), peak and relative blood lactate (Δ[Lact−] = peak – rest values), and the perceived rating exertion (RPE) were measured. MFT-8 induced higher VO2peak and VEpeak values compared to MFT (VO2peak: 2.5 ± 0.6 versus 2.3 ± 0.6 L·min−1 and VEpeak: 96.3 ± 29.1 versus 86.6 ± 23.4 L·min−1; P < 0.05) with no difference in other parameters. Significant relations between VEpeak and end-test score were correlated for both field tests (P < 0.05). At exhaustion, MFT attained incompletely VO2peak and VEpeak. Among experienced wheelchair players, MFT-8 had no effect on test performance but generates higher physiological responses than MFT. It could be explained by demands of wheelchair skills occurring in 8 form during the modified condition.

Changes in Cardiac Tone Regulation with Fatigue after Supra-Maximal Running Exercise

To investigate the effects of fatigue and metabolite accumulation on the postexercicse parasympathetic reactivation, 11 long-sprint runners performed on an outdoor track an exhaustive 400 m long sprint event and a 300 m with the same 400 m pacing strategy. Time constant of heart rate recovery (HRRτ), time (RMSSD), and frequency (HF, and LF) varying vagal-related heart rate variability indexes were assessed during the 7 min period immediately following exercise. Biochemical parameters (blood lactate, pH, PO2, PCO2, SaO2, and HCO3 −) were measured at 1, 4 and 7 min after exercise. Time to perform 300 m was not significantly different between both running trials. HHRτ measured after the 400 m running exercise was longer compared to 300 m running bouts (183.7 ± 11.6 versus 132.1 ± 9.8 s, P < 0.01). Absolute power density in the LF and HF bands was also lower after 400 m compared to the 300 m trial (P < 0.05). No correlation was found between biochemical and cardiac recovery responses except for the PO2 values which were significantly correlated with HF levels measured 4 min after both bouts. Thus, it appears that fatigue rather than metabolic stresses occurring during a supramaximal exercise could explain the delayed postexercise parasympathetic reactivation in longer sprint runs.

Para-Cycling Performance was Rather Limited by Physiological than Functional Factors.

The purpose of the Para-cycling classification is to minimize the impact of impairment on the outcome of competition, so that an athlete’s success in competition relies on training, physical fitness, and personal athletic talent (UCI Cycling Regulations, 2011). Athlete evaluation is done in compliance with the International Paralympic Committee (IPC) Classification Code and International Standard on Athlete Evaluation. A classification panel for athletes with physical impairments in Handbike, Tricycle, and Cycle consists of three International Cycling Union (UCI) accredited classifiers: a medical doctor, physiotherapist, and sports technician. Athletes are classified according to the extent of activity limitation resulting from their impairment. This places athletes according to how much their impairment affects core determinants of performance in cycling. The chapter V of UCI Para-cycling classification guide (UCI Cycling Regulations, 2011) stipulated that the “functional ability of the athletes will decide the final classification” which depends on the nature of spinal cord lesion (complete or incomplete), neurological impairment or amputation. A classification scale is used to include athletes suffering from different pathologies (neurological, amputation) but having comparable multiple functional impairments in the same race category. Since 2010, the UCI included two impairments in the cycling classification: neurological-impairments, with central or peripheral damage, and orthopedic impairments. For example in C1 class, the athletes with hemiplegia, diplegia, athetosis, or ataxia with single above knee and arm amputation. Additionally, a corrective factor essentially based on time – speed relationship is used during Paralympic games “for equity and to be able to compare the podium athlete/medal contenders” (http://www.uci.ch/Modules/BUILTIN/getObject.asp?MenuId=MTI1NjAO Hutzler et al., 1998; Sezer et al., 2004; Ward-Smith, 1985) and our comparison of intergroup performance established in different categories during the last world para-cycling championships (Table ​(Table1),1), it seems the severity of the athlete’s disability is associated with a reduced performance, whatever the duration of effort. One exception was the cycling performance occurred on individual road time trial (TT) and the 1-km Standing Start (1-km Individual TT, i.e., 1-km ITT) events for C4 and C5 categories. This result would reflect, in part, the difference in upper limb response to heterogeneous impairments among C4–C5′ athletes and, therefore, a difference in their gross efficiency (GE), i.e., the ratio between work and energy (Janssen et al., 2001; Leirdal and Ettema, 2011; Stone and Hull, 1993). Previous findings (Crouse et al., 1990; Janssen et al., 2001; Hutzler et al., 1998; Sezer et al., 2004) already suggested that reduced exercise tolerance in amputee and neurological subjects may be due to their reduced GE compared to healthy counterparts. Functional differences in balance, muscle, and motor control between amputees and cerebral palsy suggested that GE and therefore cycling performance are not similar. In a bilateral above knee amputee, Crouse et al. (1990) reported that walking with prostheses requires significant increase in energy expenditure and induces a shorter time to exhaustion compared to controls. Primary effects of stroke on sensorimotor function also include sensory-perceptual dysfunction which could induce technical impairment and a shorter time to exhaustion. However, no significant relationship was found between time to fatigue and motor disability (Corbett, 2009). Sezer et al. (2004) also showed a significant respiratory dysfunction in hemiplegic which could in part explain the difference in time to exhaustion compared with healthy subjects. It has been reported, in valid trained subjects, that maximal oxygen uptake (VO2max) rather than GE explained cycling performance (Capelli et al., 1998; Coyle, 1995). Taken together these previous results suggested that energy expenditure and aerobic capacity rather than motor ability may explain and contribute to cycling performance. During arm-cranking tests, Hutzler et al. (1998) also observed significant differences in aerobic capacity between athletes with different types of impairment (paraplegia, polio, or amputations). They showed that classification accounted for 30 and 38% of the variance in aerobic and anaerobic powers, respectively. This impact of disability was also significant on leg performance (Table ​(Table11). Table 1 Lap time (in seconds) to realize the best performance (±SD) of 1–km standing start for C1–C3 categories and the interclass time difference (delta, s) measured during the UCI World Para-cycling Track championships in 2011. Intermediate times measured during 1-km ITT revealed similar pacing-profiles which were characterized by an initial acceleration followed by a progressive decay in split times (Table ​(Table1).1). Like in valid cyclists, the first 250 m split time was a primary determinant of total 1-km ITT time in para-cyclists. It seems almost certain that the initial acceleration property is limited by the disability level. The 2.4 s separating first and second C1 cyclists after the first 250 m also demonstrated that the nature of disorder (central or peripheral) impacted on performance. Over the remainder of the race, the split time difference between C1–C2 and C1–C3 continuously increased over time whereas it blunted between C2 and C3 athletes. These differences in intergroup responses could be attributable in part to (1) the difference in energy cost between C1 and C2–C3 categories (Capelli et al., 1998) and (2) the adopted pacing strategies. C3 were characterized by a quicker start compared to C2 cyclists. Previously, Corbett (2009) showed that an overly quick start was associated with a concomitant slowing toward the finish. Performance appears to be attributable to faster VO2 responses without a significant change in anaerobic contribution (Bishop et al., 2002). A faster start could also alter the metabolic responses and explain the inability to maintain exercise intensity. Energy requirements may elucidate in part the decrease in time difference from 250 m to 1-km between C2 and C3 and the similar performance between 1-km ITT and 3-km individual pursuit in C2 category during the 2011 world track para-cycling championship (Table ​(Table1).1). The absence of comparative studies on physiological responses between infraclass cyclists makes the task difficult for the IPC to deliver a combined title for the C1–C5 categories during Paralympic Games. Therefore, the question of equity and nation’s strategies remains during a unique race with different final ranking. Based on the metabolic model, cycling performance would be primarily determined by the value of oxygen uptake at the lactate threshold (VO2-LT) and its upper-limit (VO2max; Coyle, 1995; Capelli et al., 1998). Hence, higher VO2max values will increase the time spent at high intensities for less impaired athletes with higher chances of winning. Moreover, the decrease in time difference over the time would promote C2–C3 categories. Finally, the difference in physiological and residual muscle strength between amputated and spinal cord injuries athletes require detailed biomechanical and physiological investigations in order to measure precisely the impact of disability on cycling performance.

Are tetraplegic handbikers going to disappear from team relay in para-cycling?

Since 2007, the International Cycling Union (UCI) and International Paralympic Committee (IPC) organize the most prestigious competitions bound for the athletes with locomotor and sensorial impairments: the Paracycling World Championships, the Para-cycling World Cup and the Paralympic Games (http://www.uci.ch/Modules/BUILTIN/getObject.asp?MenuId=andObjTypeCode=FILEandtype=FILEandid=MzIyNjAandLangId=1, p 3). Based on the functional disability, male and female athletes are divided into four groups of disability for all UCI age categories. One of four, the hand-cycling, includes Women (WH) and Men (MH) whom ride on hand tricycles in prone (i.e., arm power) or kneeling (i.e., arm-trunk power) positions. Based on the anatomic level of spinal cord injury and associated functional limitations (or similar), hand-cycling category contains four classes (H1, H2, H3, and H4) from the most (H1: impaired sympathetic nerve system) to the less (H4: arm cranking ability in kneeling position) limited ability (UCI Rules. Cycling Regulation.– E0712. Part XVI: Para-cycling; Chapter V-16.5.002–16.05.005, 2012). To promote hand-cycling category, UCI inaugurated during the road world championship in 2009 (Bogogno, Italia) a new model of competition, the team relay (TR), then introduced it in road world cup and recently in the Paralympic Games of London 2012. For all para-cycling TR competitions, a team shall be composed of three mixed athletes, including an athlete with a scoring value of one point, for a maximal total of six points per team. Hence, males with completed cervical spinal injury (C6–C8) are worth one point (G1: MH1), two and three points for their counterparts with completed spinal cord injury from 1st to 10th thoracic vertebrae (G2: MH2) and from 11th thoracic vertebrae or below (G3: MH3 and G4: MH4), respectively. Based on the time trial performance (TT) realized during the last Paralympic games, our chronometric analysis showed, in fact, a decrease in TT according to athlete scoring value and so athletes impairment (Table ​(Table1).1). The average of the 5 best times to perform 16 km TT was significant higher for G1 (35 min 55 s ± 2 min 26 s) compared to G2 (31 min 10 s ± 3 min 35 s) and G3 (26 min 14 s ± 0 min 57 s) (p < 0.05). Surprising, female athletes are only included in two categories: WH1 and WH2 are credited of one point and WH3 and WH4, two points (UCI Rules. Cycling Regulation.– E0712. Part XVI: Para-cycling; Chapter V, 16.5.012, 2012). If this scoring system invites to insert women into the TR for success, it raises the question about the place of the most limited athletes in a successful team. In H1 class, male and female athletes present an impaired sympathic nerve system due to a tetraplegia or similar functional ability profile although MH2 and WH2 are paraplegic or equivalent. The MH1 -WH2 mixing supposes to consider a similar cycling performance between tetraplegic male and paraplegic female. However, our chronometric lap time analysis during the last international competitions of Roma, Segovia, and London showed a potential gender-disability effect among athletes with the same scoring value. For example in Table ​Table1,1, averaged lap time was significantly lower of 31.0 ± 9.5 s for WH2 winner compared to her MH1 counterpart during these three competitions. Table 1 Time (in min:sec ± SD) of the 5 first final time trial (16 km) for division H1–4 men and women during the paralympic games in brands Hatch, the 5 September 2012. These differences in TR performance could be explained in part by some different functional and physiological responses between tetraplegia and paraplegia. The measurement aggregation and weighting of the MH1 by manual muscle testing grade (Hislop and Montgomery, 2002) showed a limited elbow extension with a muscle score of grade 6 (total of both triceps), limited handgrip and no balance of the trunk. In their meta-analysis, Haisma et al. (2006) noted that the muscle strength of the upper extremity was comparable between paraplegic subjects and the age- and gender-matched able-bodied population. However, in subjects with cord injury at the cervical lesion, shoulder strength was reduced to 50% of normal predicted values. By isokinetic measurements, Bernard et al. (2004) reported an influence of the anatomical level of spinal lesion on shoulder strength and therefore wheelchair propulsion: lesser was the anatomical site of spinal injury, higher were the values of peak torque and mean power of external rotators. Tweedy and Vanlandewijck (2011) compared the tetraplegic and paraplegic performance on athletic track distances ranged from 100 to 800 m. They showed an incidence of the impairment on the functional possibilities and the gestural efficiency. Although the difference between arm cranking and pushing to propel hand-bike or athletic wheelchair, it is easy to notice the WH2 advantage whom used the entire upper limb and trunk musculature than MH1 who worked with their residual shoulder strength in arm cranking exercise. This difference could be more marked during crossing of stiff slope where in equal speed of movement, the strength developed on cranks could not be any more compensated with an increase of the cranking frequency and a gear ratio reduction. In tetraplegia, respiratory function was also reduced. Numerous works suggested that the level of lesion is inversely correlated with respiratory function (Winslow and Rozovsky, 2003; Schilero et al., 2005) and the association between a reduced baseline airway caliber and a heightened vagomotor airway tone (Schilero et al., 2005). Haisma et al. (2006) in their critical review of 38 studies showed that the weighted mean for peak oxygen uptake and peak power output in tetraplegia subjects was reduced to 55–59% compared to paraplegia subject engaged in arm-cranking or hand-cycling exercise. Tetraplegia athletes are deprived of supraspinal sympathoadrenal control and the sympathic decentralization precludes cardio acceleration by lower peak of heart rate value ranged from 110 to 130 beats.min−1 during a maximal exercise (Schmid et al., 1998; Bhambhani et al., 2010). Compared to paraplegic, cardiac vagal withdrawal in tetraplegic subjects is not sufficient for full expression of cardiac acceleration during dynamic exercise (Coutts et al., 1983). Hence, Beekman et al. (1999) showed a lower speed and a lesser distance performed by tetraplegic subjects with a higher oxygen cost compared to subjects with paraplegia. All these impairments finally places the MH1 in an unfavorable position compared to WH2 in TR constitution. However, the race topography may be impact the infraclass performance difference and so TR successful or unsuccessful. Uphill cycling field may be accentuated the difference in cycling performance between MH1 and WH2. The comparison of TR lap per category showed a greater performance for WH2 than MH1 at Roma, Segovia and London but with a lesser mean time difference during flat (Segovia, mean TR lap difference of 20 s between WH2 and MH1 winners) compared to uphill field events (mean TR lap difference of 35 s for London and 37 s for Roma between WH2 and MH1 win). The literature showed significant physiological and mechanical differences between tetraplegic and paraplegic athletes with spinal cord injury engaged in athletic wheelchair, arm-cranking and hand-cycling exercises. These are amplified during uphill field competition. This paper presents the difficulty to manage athletes with the same scoring point value but a different level of disability in the composition of a successful team relay. Team relay is the only one collective event allowing all H and all nations to participate in the international para-cycling competitions. With the current system of scoring, paraplegic women are favored with regard to the tetraplegic men to be a TR member. In one concerns to the tetraplegic athletes disappearance, we therefore recommend to UCI a high caution in the choice of the race topography.

Effects of Interval Aerobic Training Program with Recovery bouts on cardiorespiratory and endurance fitness in seniors

Interval aerobic training programs (IATP) improve cardiorespiratory and endurance parameters. They are, however, unsuitable to seniors as frequently associated with occurrence of exhaustion and muscle pain. The purpose of this study was to measure the benefits of an IATP designed with recovery bouts (IATP‐R) in terms of cardiorespiratory and endurance parameters and its acceptability among seniors (≥70 years). Sedentary healthy volunteers were randomly assigned either to IATP‐R or sedentary lifestyle. All participants performed an incremental cycle exercise and 6‐minute walk test (6‐MWT) at baseline and 9.5 weeks later. The first ventilatory threshold (VT1); maximal tolerated power (MTP); peak of oxygen uptake (VO2peak); maximal heart rate (HRmax); and distance walked at 6‐MWT were thus measured. IATP‐R consisted of 19 sessions of 30‐minute (6 × 4‐min at VT1 + 1‐minute at 40% of VT1) cycling exercise over 9.5 weeks. With an adherence rate of 94.7% without any significant adverse events, 9.5 weeks of IATP‐R, compared to controls, enhanced endurance (VT1: +18.3 vs −4.6%; HR at baseline VT1: −5.9 vs +0.2%) and cardiorespiratory parameters (VO2peak: +14.1 vs −2.7%; HRmax: +1.6 vs −1.7%; MTP: +19.2 vs −2.3%). The walk distance at the 6‐MWT was also significantly lengthened (+11.6 vs. −3.1%). While these findings resulted from an interim analysis planned when 30 volunteers were enrolled in both groups, IATP‐R appeared as effective, safe, and applicable among sedentary healthy seniors. These characteristics are decisive for exercise training prescription and adherence.