I used to compete with a 24-32 kg(53-70lbs) kettlebells 30 years ago . Now a 40 lbs(18kg) bell is my starting weight and it feels very heavy . If I start to use it consistently it is not heavy enough, but I do not. Should go to a 53 lbs, but I do not use it regularly and 40 lbs is heavy enough to put me out of breath after 10 reps. Kettlebell training during winter month is not enough for me to graduate to a heavier weight.

Doing turkish get ups, windmills , swings , snatches and presses during winter months builds up legs, back, endurance and lungs for cycling in the spring. Also I use squats with a kettlebell to build up my knees before the cycling season. My knees do not hurt any more in spring when I start climbing.

Combine kettlebells with rope jumping 2-3 times a week in the off season keeps me to be somewhat in shape and not loose too much summer fitness. Although I can not do more than 10-20 reps now with each arm with a 40 lbs bell. I used to be able to go over 100 reps with a 53-70 lbs when I was younger