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Lower limb peripheral artery disease (LLPAD) is a chronic atherosclerotic disease which leads to narrowing and/or occlusion of arteries supplying the legs. The most characteristic symptom of LLPAD is intermittent claudication (IC), a cramping lower limb (buttocks, thighs, calf, or foot) pain occurring during exercise and resolving with rest. IC is characterized by inadequate oxygen supply (from impaired blood flow) to meet metabolic demand [1]. Based on a large population study, IC prevalence increases from about 2% in a population aged 40–44 years to 7% in a population aged 70–74 years [2]. It has previously been shown that LLPAD patients have a significant reduction in muscle strength [3], walking performance [4], and physical functioning [5] compared to subjects without LLPAD. Moreover, LLPAD patients are also generally less implicated in regular exercise [6] and in daily life activities [5, 7]. These significant reductions may cause decreased quality of life [8] and contribute to increase in mortality risk [9].

Regular exercise training is recommended as one of the primary baseline measures in LLPAD with the aim to improve walking capabilities and contribute to reduce cardiovascular risk [1, 10]. There is a large body of evidence supporting the pivotal role of regular exercise training in improving walking performance [i.e., pain-free walking distance (PFWD), maximal walking distance (MWD), and six-minute walking distance (6MWD)], physical functioning, and quality of life in LLPAD patients [1, 10, 11]. Moreover, it has recently been shown that exercise training also leads to significant improvement in aerobic fitness [peak oxygen uptake (V′O2peak)] [12]. This is relevant, as poor aerobic fitness has been suggested to be a strong mortality predictor in patients with LLPAD [13]. In general, exercise training sessions have a duration which varies between 30 and 60 min (depending on individual exercise tolerance) and are performed two to three times per week for a total of 3 or 6 months [1]. To achieve maximal benefits, exercise training should be supervised by physiotherapists or sport trainers [14]. As blood flow and pressure (ankle-brachial index) are unaffected by exercise training [12], other potential mechanisms, such as changes in microcirculation, endothelial function, muscle metabolism, inflammation, and walking economy, seem to be implicated in the improvement of walking performance [10].

Walking and lower extremity aerobic training (strengthening and aerobic training focused on lower limbs) are the most common modes of training [1, 15]. However, by reason of more severe claudication pain, lower pain tolerance, increased risk of fall linked with an impaired balance, and/or other comorbidities (diabetes, orthopedic, and rheumatic diseases), elderly LLPAD patients cannot always complete a walking training session and/or have a limited enthusiasm with regard to regular exercise. Therefore, in order to allow elderly LLPAD patients to benefit from rehabilitation programs, alternative modes of training (e.g., arm crank ergometer, resistance training, Nordic pole walking, cycling) have also been evaluated, and promising results were described [12, 15, 16].

As the impaired blood flow induces lower limb skeletal muscle ischemia and leg pain during walking, upper limb exercise performed with an arm crank ergometer (Fig. 44.1) may be an interesting pain-free and well-supported training modality [17]. Indeed, it has been demonstrated that 12-week arm crank exercise training performed at 60–70% of the peak work rate (2 min of exercise followed by 2 min of rest for 40 min) may increase walking performance and V′O2peak [17]. This was explained, at least in part, by an increased lower limb oxygen delivery during walking and suggests that circulatory adaptations may also occur in untrained limbs [17]. Indeed, it has been shown that upper limb exercise training may have a systemic anti-inflammatory effect in LLPAD patients [18], which could positively impact endothelial function and reduce cardiovascular risk. Therefore, upper limb training may be especially useful in elderly LLPAD patients with concomitant lower limb diseases affecting walking capacity (orthopedic, rheumatic). Although to our knowledge this type of training has not been evaluated in more severe stage of LLPAD [Fontaine stages III (rest pain) and IV (ischemic ulcers or gangrene)], this might be an interesting opportunity to improve aerobic fitness and reduce the cardiovascular risk.

Fig. 44.1
figure 1

Arm crank ergometer

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Resistance exercise training has also been suggested as an effective training modality [19,20,21,22,23]. Indeed, LLPAD patients have a significant reduction in calf muscle area [24] and also have lower leg strength which is associated with walking capabilities [22]. It has been demonstrated that 12-week whole-body (e.g., calf raise on leg press machine, leg press, leg curl, leg extension, crunches, seated row, bench press) resistance training [3 sets of 10 repetitions performed at the intensity between 11 and 13 (light and somewhat hard, respectively) on Borg’s scale (rating of perceived exertion to monitor level of intensity during exercise)] improves walking performance to a similar extent as treadmill exercise training [21]. Interestingly, compared to walking, this mode of exercise elicits lower pain during the training sessions [23]. Furthermore, longer resistance training programs have also been evaluated. It has been shown that 24-week whole-body resistance training [2 sets of 8–15 repetitions performed at approximately 70% of one repetition maximum (1RM)] significantly improves walking performance and strength compared to control group [20]. Another study [19] showed that 24-week lower limb progressive resistance training (3 sets of 8 repetitions performed at 50–80% 1RM) improves walking performance on treadmill and quality of life (assessed by questionnaire) compared to control group. However, there were no significant changes in the 6MWD compared to control group [19]. Finally, it has recently been demonstrated that intensity of resistance training may also have an impact on the improvement of walking performance. Indeed, 24-week whole-body high-intensity progressive resistance training (3 sets of 8 repetitions performed at 50–80% 1RM) significantly improved the 6MWD and whole-body strength compared to whole-body low-intensity resistance training (3 sets of 8 repetitions performed at 20–30% 1RM) and control group. The adaptations in the high-intensity progressive resistance training group were related to significant changes in bilateral calf and hip extensor skeletal muscle endurance [22].

Nordic pole walking has been shown to increase the PFWD and the MWD compared to walking without poles, suggesting that this type of exercise may improve walking performance despite a higher cardiovascular stimulation [25]. The use of poles may increase the walking speed and reduce the lower extremity load, which seems to be relevant in LLPAD patients [26]. In addition, as elderly LLPAD patients may have an impaired balance [27], the use of poles might also be useful. It has been demonstrated that 24-week Nordic pole walking exercise training, performed at maximal or near to maximal claudication pain, increases walking performance, V′O2peak, and physical functioning (assessed by questionnaire) in LLPAD patients [28]. Nordic pole walking training was found to be as effective as treadmill training for the improvement in walking performance [29].

Cycling exercise might also be a safe and feasible training modality [30]. Although 6-week cycling exercise training performed at vigorous intensity showed a significant increase in cycling time, no significant improvement was observed in walking performance in response to cycling exercise compared to treadmill exercise training (performed at the same relative exercise intensity) in LLPAD patients [30]. However, in a subgroup of patients who experienced similar (anatomic location) exercise-limiting symptoms during walking and cycling, walking performance was improved after cycling training. This suggests a cross-transfer effect of training modalities and highlights the potential role of cycling in some LLPAD patients [30].

In conclusion, data suggest that different training modalities (other than walking) are safe, feasible, and effective in LLPAD patients. These allow elderly LLPAD patients to benefit from rehabilitation programs taking into account their specific needs. Compared to walking, the lower pain induced by other training modalities during exercise may encourage patients to better adhere to regular exercise training. To better optimize training prescription in all LLPAD patients, further research is needed using combined or varied training modalities.

FormalPara Key Points

  • Regular exercise training is recommended as one of the primary baseline measures in LLPAD patients.

  • Other than walking, different training modalities (e.g., arm crank ergometer, resistance training, Nordic pole walking, and cycling) are safe, feasible, and effective in LLPAD patients.