"What client in their right mind would employ us on a work site aged 64?" he said.
The strikes disrupted public transport in the capital, closing one metro line and forcing others to run reduced services. Large numbers of trains were cancelled across France.
Many parents were forced to look after their children, as around 40 percent of primary school teachers and more than 30 percent in the secondary system walked out, according to official estimates.
Unions put the strike participation much higher, at 70 and 65 percent, respectively.
Strikers at state-owned energy provider EDF said they had lowered electricity output by 7,000 megawatts, while grid operator RTE put the figure at 5,000 MW -- enough to power two cities the size of Paris.
But the CGT union said the reduction would have "no impact on users".
CGT chief Philippe Martinez told broadcaster Public Senat earlier Thursday that the pension reform "bundles together everyone's dissatisfaction" with the government. "We all agree that the reform is unjust."
With Paris metros and buses in disarray, basketball fans were expected to have problems getting to the sold-out NBA Paris Game between the Detroit Pistons and Chicago Bulls in the northeast of the capital in the evening.
Opinion polls show that around two-thirds of French people oppose raising the retirement age, a move that comes amid high inflation and with the country still recovering from the economic fallout of the Covid-19 pandemic.
Macron's last attempt at pension reform in 2019 ended a year later when Covid-19 hit Europe. But it had already prompted the longest strike on the Paris transport network in three decades.
The 45-year-old former banker vowed to press ahead with plans to push back the retirement age during his re-election campaign last year, pointing to forecasts that the system could fall into deep deficits at the end of the decade.
But unions are suspicious of the overhaul and want to protect those who started working at a young age or have been toiling in physically demanding jobs.