Manish's moment of reckoning came in the IAAF Race Walking Challenge held at Rio Maior in Portugal in the April of 2015. Three Indians had clocked a time which was well within the qualifying mark of 1:24.00 hrs. Manish was on of them with an effort of 1:22.50 to finish in the top ten. He is currently under the tutelage of Russian coach Alexander Atsybashev.
An employee of the Uttarakhand Police, Manish has from childhood days loved this sport of walking. He had qualified in the 50 km event too but it was the 20km event that he had been asked to concentrate. He credits his coach for all the improvement since 2011. To look for a top 10 finish is his first aim in the Rio Olympics.He had done that in the World championship in Beijing.