Ive tried the ankle weights in the past , and they place far too much stress on your lower legs, especially the Achilles tendons, and calf muscles.
The best and safest way to develop leg strength, is to go running in sand dunes.
The famous Merthyr Mawr sand dunes in South Wales, just outside Bridgend, saw the likes of Sebastian Coe, Steve Ovett Steve Cram and Daley Thompson in their Olympic Gold prime, train on the largest sand dune in Europe, called the Big Dipper.
Top athletes from around the world who require body conditioning, still visit Merhyr Mawr, as its regarded as the best location anywhere in Europe.
Running or power walking up deep sand will give your body one heck of a physical workout, and unlike ankle weights, will not place direct stress on your leg muscles.
If you want to experience what extreme fatigue and leg tiredness is all about, where the ankle wights for a short distance, the performance gain or lack of it, is simply not worth it.
Even for someone living in the very flat fen country of East Anglia, regular long walks, will still boost your endurance, and build up your legs muscles, and its all mileage in the bank, for more demanding terrain.
If you have never used ankle weights before, i would give them a wide berth, as the amount of pressure they place on leg muscles that are not used to the stress, is not worth experimenting with.
If you want a leg injury, then wear ankle weights.