Many people believe that they need immense physical strength to complete a trek like Lamkhaga, which is not necessarily true. Athletic strength is essential, but mental strength is equally important. Anyone with average physical strength and high mental strength can complete a trek like Lamkhaga pass.
Cardio (aerobic) exercises, like hiking, cycling, swimming, will help you achieve strength before the start of your journey. One crucial thing to remember is that trekking is not a race, so you need to keep up with ample breaks and acclimatization.